Article

Changes in Body Composition With Yogurt Consumption During Resistance Training in Women

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Abstract

Resistance training is an effective method to decrease body fat (BF) and increase fat-free mass (FFM) and fat oxidation (FO). Dairy foods containing calcium and vitamin D might enhance these benefits. This study investigated the combined effects of habitual yogurt consumption and resistance training on body composition and metabolism. Untrained women (N = 35) participated in an 8-wk resistance-training program. The yogurt group (Y) consumed 3 servings of yogurt containing vitamin D per day, and the control groups maintained their baseline low-dairy-calcium diet. Postexercise, Y consumed 1 of the 3 servings/d fat-free yogurt, the protein group consumed an isocaloric product without calcium or vitamin D, and the carbohydrate group consumed an isocaloric product without protein. Strength, body composition, fasted resting metabolic rate (RMR) and FO, and serum 25-hydroxyvitamin D were measured before and after training. Calories (kcal x kg-1 x d-1) and protein (g x kg-1 x d-1) significantly increased from baseline for Y. FFM increased (main effect p = .002) and %BF decreased (main effect .02) for all groups with training, but Group x Time interactions were not observed. RMR and FO did not change with training for any group. Habitual consumption of yogurt during resistance training did not augment changes in body composition compared with a low-dairy diet. Y decreased %BF as a result of training, however, even with increased calorie consumption.

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... Twenty-two included studies examined the relationship between consumption of yogurt and cultured fermented milk and weight and body composition 70,93-113 ; 5 were RCTs, 96,107,108,112,113 9 were cohort studies, 94,100-102, 104,106,109-111 and 8 were CS studies. 70,81,[93][94][95][97][98][99]105 Six studies 96,97,107,108,112,113 were positive quality and focused on body composition, weight loss, obesity, and muscle soreness. The remaining 16 studies 70,[98][99][100][101][102][103][104][105][106][109][110][111] were neutral quality. ...
... The remaining 16 studies 70,[98][99][100][101][102][103][104][105][106][109][110][111] were neutral quality. In 21 of the 22 studies, [93][94][95][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112][113] subjects were fed yogurt, and in the remaining study 96 they were fed kefir. Eighteen of the 22 studies 94-107, 109-111,113 reported a favorable outcome for weight control or positive body composition effect, and 4 studies 70,93,108,112 reported no effect. ...
... In 21 of the 22 studies, [93][94][95][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112][113] subjects were fed yogurt, and in the remaining study 96 they were fed kefir. Eighteen of the 22 studies 94-107, 109-111,113 reported a favorable outcome for weight control or positive body composition effect, and 4 studies 70,93,108,112 reported no effect. ...
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Consumption of yogurt and other fermented products is associated with improved health outcomes. Although dairy consumption is included in most dietary guidelines, there have been few specific recommendations for yogurt and cultured dairy products. A qualitative systematic review was conducted to determine the effect of consumption of fermented milk products on gastrointestinal and cardiovascular health, cancer risk, weight management, diabetes and metabolic health, and bone density using PRISMA guidelines. English language papers in PubMed were searched, with no date restrictions. In total, 1057 abstracts were screened, of which 602 were excluded owing to lack of appropriate controls, potential biases, and experimental design issues. The remaining 455 papers were independently reviewed by both authors and 108 studies were included in the final review. The authors met regularly to concur, through consensus, on relevance, methods, findings, quality, and conclusions. The included studies were published between 1979 and 2017. From the 108 included studies, 76 reported a favorable outcome of fermented milks on health and 67 of these were considered to be positive or neutral quality according to the Academy of Nutrition and Dietetics' Quality Criteria Checklist. Of the 32 remaining studies, the study outcomes were either not significant (28) or unfavorable (4), and most studies (18) were of neutral quality. A causal relationship exists between lactose digestion and tolerance and yogurt consumption, and consistent associations exist between fermented milk consumption and reduced risk of breast and colorectal cancer and type 2 diabetes, improved weight maintenance, and improved cardiovascular, bone, and gastrointestinal health. Further, an association exists between prostate cancer occurrence and dairy product consumption in general, with no difference between fermented and unfermented products. This article argues that yogurt and other fermented milk products provide favorable health outcomes beyond the milk from which these products are made and that consumption of these products should be encouraged as part of national dietary guidelines. Systematic review registration: PROSPERO registration no. CRD42017068953.
... b: Eight references (Ala-Houhala et al. 1988; Andersen et al. 2013; Hower et al. 2013; Lehtonen-Veromaa et al. 2008; Madsen et al. 2013; Rich-Edwards et al. 2011; Sullivan et al. 2005) provided data on populations which are considered as eight separate studies. c: Forty-nine references (Ala-Houhala et al. 1986 6 ; Barger-Lux et al. 1998; Barnes et al. 2006; Brazier et al. 2002; Bischoff et al. 2003; Bolton-Smith et al. 2007; Bonjour et al. 2013; Braam et al. 2003; Cashman et al. 2014; Cashman et al. 2008; Cashman et al. 2012; Cashman et al. 2009; Close et al. 2013; DeLappe et al. 2006; Forman et al. 2013; Goussous et al. 2005; De Gruijl et al. 2012; Hansen et al. 2010; Harris et al. 2002 7 ; Heaney et al. 2003; Heikkinen et al. 1998; Holick et al. 2008; Holm et al. 2008; Honkanen et al. 1990 8 ; Johnson et al. 2005; Keane et al. 1998; Larsen et al. 2012; Lehman et al. 2013; Madsen et al. 2013; Meier et al. 2004; Mocanu et al. 2009; Nelson et al. 2009; Patel et al. 2001 9 ; Pekkarinen et al. 2010; Porojnicu et al. 2008; Smith et al. 2009; Schmidt et al. 2011; Sorva et al. 1994; Trautvetter et al. 2014; Vieth et al. 2001; Viljakainen et al. 2006; Viljakainen et al. 2009; White et al. 2009; Wood et al. 2014 10 ; Andersen et al. 2013; Darling et al. 2013; MacDonald et al. 2011; Hill et al. 2005; Kift et al. 2013The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure. ...
... In adult populations, seven studies with fortified foods as the intervention were identified (Table 11). Five of the interventions used foods that were fortified with vitamin D 3 (Bonjour et al. 2013; Johnson et al. 2005; Madsen et al. 2013; Mocanu et al. 2009; Trautvetter et al. 2014); two studies did not report on the exact type of vitamin D used (Keane et al. 1998; White et al 2009). Another study was conducted with a food source that was naturally rich in vitamin D, specifically fish (Hansen et al. 2013). ...
... Results on 25(OH)D changes are described below in increasing order of vitamin D dose. White et al (2009) provided, by means of a fortified yogurt, 3µg vitamin D per day for eight weeks and observed a large decrease in 25(OH)D concentration from October through December, that is -135 nmol/L. Madsen et al. (2013) provided, by means of fortified milk and bread, 5 µg vitamin D 3 per day for 26 weeks, which resulted in a significantly lower decrease in 25(OH)D concentration than the decrease observed in the placebo group, specifically about -7 nmol/L versus -29 nmol/L as calculated by subtracting geometric means of follow-up and baseline. ...
Article
In recent years, there has been much attention for the global high prevalence of low blood concentrations of 25(OH)D, as an indicator of vitamin D status. These 25(OH)D concentrations primarily depend upon the level of sun exposure. However, also dietary vitamin D intake is of importance, especially at higher latitudes during winter. To get insight in the amount of oral vitamin D needed to achieve and maintain an adequate 25(OH)D blood concentration, the aim of this review was to systematically investigate the intake-status relationship for vitamin D under minimal endogenous vitamin D synthesis, as preparatory work for the setting of Dietary Reference Values for vitamin D. Searches were conducted in Medline, Embase and Cochrane. All published prospective cohort studies with the vitamin D intake-status relationship as the primary aim of investigation, as well as all trials, issued through 23-7-2014 and covering all ages, were included in this review, which resulted in 7,807 unique hits. Subsequently, 1,323 potentially relevant articles were identified by title and abstract screening. Hand searches led to the inclusion of 22 additional potentially relevant papers. Thus, in total, 1,345 full-text papers were screened. After full text screening, 56 articles met the predefined inclusion criteria, resulting in the inclusion of 65 studies, i.e. 57 trials and 8 prospective cohort studies, in infants, children or adults (one article corresponding to one to three studies). Two of the included studies were conducted in infants, eight in children or adolescents, and 55 in adults. The majority of the studies examined the impact of vitamin D3. Most trials studies showed a dose-response relation between vitamin D intake and status. However, as the impact of a similar dose of vitamin D on 25(OH)D concentration substantially differed across the studies, it is difficult to quantify this dose-response relationship. Therefore, the exact nature of the vitamin D dose-response relationship warrants further investigation, for instance by performing meta-regression analyses.
... Five studies recruited females only. 26,27,29,42,43 One crossover trial recruited males only. 33 In Mozaffarian et al., 36 the NHSI and NHSII cohorts were all female and the HPFS cohort was all male, all pooled for analysis. ...
... Two RCTs investigated the effect of consuming yoghurt around the time of exercise. 27,29 Quality assessment The detailed quality assessment is presented in the Supplementary File. Two RCTs had a low risk of bias in the summary assessment. ...
... High yoghurt consumers gained significantly less weight compared with low yoghurt consumers in one retrospective cohort study (Wang et al., 39 unclear risk of bias) and a similar, nonsignificant trend was reported in the controlled trial by Jordan et al. 31 A significant association between increasing yoghurt consumption and decreasing weight gain was found in another retrospective cohort study, 36 mixed results in another 38 and a nonsignificant effect in the remaining study. 35 Two RCTs, 28,29 both with high risk of bias, reported an increase in body weight with yoghurt consumption, with a similar body weight increase also being reported in some, but not all comparator groups. These trials are discussed below. ...
Article
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Background Yoghurt is part of the diet of many people worldwide and is commonly recognized as a 'health food'. Epidemiological studies suggest yoghurt may be useful as part of weight management programs. In the absence of comprehensive systematic reviews, this systematic review investigated the effect of yoghurt consumption by apparently healthy adults on weight-related outcomes.Methods An extensive literature search was undertaken, as part of a wider scoping review, to identify yoghurt studies. 13 631 records were assessed for their relevance to weight-related outcomes.Results22 publications were eligible according to the review protocol. Cohort studies (n=6) and cross-sectional studies (n=7) all showed a correlation between yoghurt and lower or improved body weight/composition. Six randomised controlled trials (RCTs) and one controlled trial had various limitations, including small size and short duration. One RCT showed significant effects of yoghurt on weight loss, but was confounded by differences in calcium intake. One trial showed non-significant weight gain and the remaining five trials showed non-significant weight losses that were greater in yoghurt consumers.Conclusions Yoghurt consumption is associated with lower BMI, lower body weight/weight gain, smaller waist circumference and lower body fat in epidemiological studies. RCTs suggest weight reduction effects, but do not permit determination of a cause/effect relationship. Well-controlled, adequately powered trials in research and community settings appear likely to identify a modest but beneficial effect of yoghurt consumption for prevention of weight gain and management of obesity. The ready availability of yoghurt (a nutrient dense food) and its ease of introduction to most diets, suggests that educating the public to eat yoghurt as part of a balanced and healthy diet may potentially contribute to improved public health. Future carefully designed RCTs could provide proof of principle and large community-based studies could determine the practical impact of yoghurt on body weight/composition.International Journal of Obesity accepted article preview online, 07 October 2015. doi:10.1038/ijo.2015.202.
... However, studies investigating the impact of protein supplementation on muscle mass and strength gains during more prolonged resistance-type exercise training tend to report discrepant findings. Although some studies report greater gains in muscle mass, muscle fiber size, and/or muscle strength after dietary protein supplementation during prolonged resistance-type exercise training (8)(9)(10)(11)(12)(13)(14)(15)(16), others have failed to confirm such findings (17)(18)(19)(20)(21)(22)(23)(24). In a recent meta-analysis, Cermak et al. (25) showed that these discrepant findings may be largely explained by differences in study design and/or the number of participants included in the study. ...
... The exercise training-induced gains in muscle mass and strength are shown to be further increased after daily supplementation with 27.5 g of dietary protein consumed before sleep. It has been well established that long-term resistance-type exercise training is an effective intervention strategy to increase skeletal muscle mass and strength (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). In the present study, we show substantial increases in whole-body lean mass after 12 wk of resistance-type exercise training ( Table 2). ...
... It has been suggested that protein supplementation can further augment the skeletal muscle adaptive response to prolonged resistance-type exercise training (25). However, there is much discrepancy in the literature on the proposed benefits of protein supplementation to increase muscle mass and strength, with most studies unable to report significantly greater increases in muscle mass or strength after prolonged resistance-type exercise training (17)(18)(19)(20)(21)(22)(23)(24). In the present study, we investigated the impact of daily protein supplementation, provided before sleep, on muscle mass and strength gains during 12 wk of resistance-type exercise training. ...
Article
BACKGROUND: It has been demonstrated that protein ingestion before sleep increases muscle protein synthesis rates during overnight recovery from an exercise bout. However, it remains to be established whether dietary protein ingestion before sleep can effectively augment the muscle adaptive response to resistance-type exercise training. OBJECTIVE: Here we assessed the impact of dietary protein supplementation before sleep on muscle mass and strength gains during resistance-type exercise training. METHODS: Forty-four young men (22 ± 1 y) were randomly assigned to a progressive, 12-wk resistance exercise training program. One group consumed a protein supplement containing 27.5 g of protein, 15 g of carbohydrate, and 0.1 g of fat every night before sleep. The other group received a noncaloric placebo. Muscle hypertrophy was assessed on a whole-body (dual-energy X-ray absorptiometry), limb (computed tomography scan), and muscle fiber (muscle biopsy specimen) level before and after exercise training. Strength was assessed regularly by 1-repetition maximum strength testing. RESULTS: Muscle strength increased after resistance exercise training to a significantly greater extent in the protein-supplemented (PRO) group than in the placebo-supplemented (PLA) group (+164 ± 11 kg and +130 ± 9 kg, respectively; P < 0.001). In addition, quadriceps muscle cross-sectional area increased in both groups over time (P < 0.001), with a greater increase in the PRO group than in the PLA group (+8.4 ± 1.1 cm(2) vs. +4.8 ± 0.8 cm(2), respectively; P < 0.05). Both type I and type II muscle fiber size increased after exercise training (P < 0.001), with a greater increase in type II muscle fiber size in the PRO group (+2319 ± 368 μm(2)) than in the PLA group (+1017 ± 353 μm(2); P < 0.05). CONCLUSION: Protein ingestion before sleep represents an effective dietary strategy to augment muscle mass and strength gains during resistance exercise training in young men. This trial was registered at clinicaltrials.gov as NCT02222415.
... White et al. [95] also examined whether yogurt was more effective than whey protein or isocaloric carbohydrate in promoting gains in lean mass and strength in previously untrained women. One supplement dose equivalent to one serving of yogurt, which contained 5 g of protein, was provided immediately following the three whole-body resistance training sessions for 8 weeks. ...
... 3.1.1.4 Summary: Untrained Participants An overview of the findings from the subsections for untrained participants is presented in Table 1 and a subsequent detailed list of the findings for protein supplements is provided in Table 2. Protein supplementation likely has no effect on lean mass and strength when training programs last 8 weeks or less [70,77,81,86,95,96]. It has not been possible to determine whether there is a relationship between gains in muscle strength due to protein supplementation and muscle hypertrophy in training programs lasting either less than [73-75, 82, 89, 92-94] or more than 8 weeks when training sessions per week were limited [73,87,89,90]. ...
... Studies with small numbers of participants in some or all of their experimental groups [72,87,91,96,105,107,112,117,118], which results in low statistical power and therefore increased risk of a type II error, should be replicated to verify their findings. In addition, some authors reported, for various reasons, loss of data due to withdrawal or exclusion of participants after the study began [77,85,91,95,96,104,105,107], which may indicate the need to conduct additional testing to validate their results. ...
Article
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Background: Protein supplements are frequently consumed by athletes and recreationally active adults to achieve greater gains in muscle mass and strength and improve physical performance. Objective: This review provides a systematic and comprehensive analysis of the literature that tested the hypothesis that protein supplements accelerate gains in muscle mass and strength resulting in improvements in aerobic and anaerobic power. Evidence statements were created based on an accepted strength of recommendation taxonomy. Data sources: English language articles were searched through PubMed and Google Scholar using protein and supplements together with performance, exercise, strength, and muscle, alone or in combination as keywords. Additional articles were retrieved from reference lists found in these papers. Study selection: Studies recruiting healthy adults between 18 and 50 years of age that evaluated the effects of protein supplements alone or in combination with carbohydrate on a performance metric (e.g., one repetition maximum or isometric or isokinetic muscle strength), metrics of body composition, or measures of aerobic or anaerobic power were included in this review. The literature search identified 32 articles which incorporated test metrics that dealt exclusively with changes in muscle mass and strength, 5 articles that implemented combined resistance and aerobic training or followed participants during their normal sport training programs, and 1 article that evaluated changes in muscle oxidative enzymes and maximal aerobic power. Study appraisal and synthesis methods: All papers were read in detail, and examined for experimental design confounders such as dietary monitoring, history of physical training (i.e., trained and untrained), and the number of participants studied. Studies were also evaluated based on the intensity, frequency, and duration of training, the type and timing of protein supplementation, and the sensitivity of the test metrics. Results: For untrained individuals, consuming supplemental protein likely has no impact on lean mass and muscle strength during the initial weeks of resistance training. However, as the duration, frequency, and volume of resistance training increase, protein supplementation may promote muscle hypertrophy and enhance gains in muscle strength in both untrained and trained individuals. Evidence also suggests that protein supplementation may accelerate gains in both aerobic and anaerobic power. Limitations: To demonstrate measureable gains in strength and performance with exercise training and protein supplementation, many of the studies reviewed recruited untrained participants. Since skeletal muscle responses to exercise and protein supplementation differ between trained and untrained individuals, findings are not easily generalized for all consumers who may be considering the use of protein supplements. Conclusions: This review suggests that protein supplementation may enhance muscle mass and performance when the training stimulus is adequate (e.g., frequency, volume, duration), and dietary intake is consistent with recommendations for physically active individuals.
... Ten of the 17 studies [1][2][3][4][5][6][7][8][9][10] showed superior muscular benefits of a higher protein intake over control (Figure 1). However, seven studies [18][19][20][22][23][24][25] meeting inclusion criteria showed no greater muscular benefits of a higher protein intake compared to control. Thus, we proposed protein spread and change theory as possible explanations for this discrepancy. ...
... Evidence weighs heavily toward muscular benefits from increased protein [1][2][3][4][5][6][7][8][9][10]. Those studies that did not support additional benefits of greater protein still showed that higher protein was as good as an alternative diet [18][19][20][22][23][24][25]. ...
... None of the "no greater benefits" studies were outside of normal distribution. However, three studies [22,24,25] had spreads that were higher than three studies [6,8,10] of the "muscular benefits" grouping. These seemed likely explained, however, by the fact that changes to habitual protein intake were much larger in the latter [6,8,10] than the former [22,24,25]. ...
Article
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An appreciable volume of human clinical data supports increased dietary protein for greater gains from resistance training, but not all findings are in agreement. We recently proposed "protein spread theory" and "protein change theory" in an effort to explain discrepancies in the response to increased dietary protein in weight management interventions. The present review aimed to extend "protein spread theory" and "protein change theory" to studies examining the effects of protein on resistance training induced muscle and strength gains.Protein spread theory proposed that there must have been a sufficient spread or % difference in g/kg/day protein intake between groups during a protein intervention to see muscle and strength differences. Protein change theory postulated that for the higher protein group, there must be a sufficient change from baseline g/kg/day protein intake to during study g/kg/day protein intake to see muscle and strength benefits. Seventeen studies met inclusion criteria. In studies where a higher protein intervention was deemed successful there was, on average, a 66.1% g/kg/day between group intake spread versus a 10.2% g/kg/day spread in studies where a higher protein diet was no more effective than control. The average change in habitual protein intake in studies showing higher protein to be more effective than control was +59.5% compared to +6.5% when additional protein was no more effective than control. The magnitudes of difference between the mean spreads and changes of the present review are similar to our previous review on these theories in a weight management context. Providing sufficient deviation from habitual intake appears to be an important factor in determining the success of additional protein in enhancing muscle and strength gains from resistance training. An increase in dietary protein favorably effects muscle and strength during resistance training.
... To date, no study has examined the effect of an easily consumed dairy product pre-and postexercise in untrained, overweight, premenopausal women who want to lose weight. Other trials examining the topic of postexercise supplementation in promoting healthful body-composition changes in women were short in duration (White, Bauer, Hartz, & Baldridge, 2009), did not match the energy density of the control and experimental supplements (Holm et al., 2008), and did not restrict energy intake (Holm et al., 2008;White et al., 2009). Therefore, the primary purpose of this study was to examine the role of yogurt supplementation in relation to a resistance-exercise program as an effective means to augment increases in lean body mass and strength while reducing body fat in overweight women after an energy-restricted diet. ...
... To date, no study has examined the effect of an easily consumed dairy product pre-and postexercise in untrained, overweight, premenopausal women who want to lose weight. Other trials examining the topic of postexercise supplementation in promoting healthful body-composition changes in women were short in duration (White, Bauer, Hartz, & Baldridge, 2009), did not match the energy density of the control and experimental supplements (Holm et al., 2008), and did not restrict energy intake (Holm et al., 2008;White et al., 2009). Therefore, the primary purpose of this study was to examine the role of yogurt supplementation in relation to a resistance-exercise program as an effective means to augment increases in lean body mass and strength while reducing body fat in overweight women after an energy-restricted diet. ...
... In addition, the CON group reported a larger energy deficit than the YOG group (1,393 vs. 1,134 kJ/day). Other trials have not implemented an energy restriction while attempting to add lean body mass (Andersen et al., 2005;Esmarck et al., 2001;Holm et al., 2008;Josse et al., 2010;Verdijk et al., 2009;White et al., 2009). Finally, White et al. reported significant reductions in percent body fat by time but not by group in their yogurt group despite significantly higher energy intake during the intervention. ...
Article
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To examine the effect of yogurt supplementation pre- and postexercise on changes in body composition in overweight women engaged in a resistance-training program. Participants (age = 36.8 ± 4.8 yr) with a body-mass index of 29.1 ± 2.1 kg/m2 were randomized to yogurt supplement (YOG; n = 15) or isoenergetic sucrose beverage (CONT; n = 14) consumed before and after exercise for 16 wk. Participants were also instructed to reduce energy intake daily (-1,046 kJ) during the study. Body composition was assessed by dual-energy X-ray absorptiometry, waist circumference, and sagittal diameter. Strength was measured with 1-repetition maximum. Dietary recalls were obtained by a multipass approach using Nutrition Data System software. Insulin-like growth factor-1 and insulin-like growth-factor-binding protein-3 were measured with ELISA. Significant weight losses of 2.6 ± 4.5 kg (YOG) and 1.2 ± 2.5 kg (CONT) were observed. Total lean weight increased significantly over time in both YOG (0.8 ± 1.2 kg) and CONT (1.1 ± 0.9 kg). Significant reductions in total fat (YOG = 3.4 ± 4.1 kg vs. CONT = 2.3 ± 2.4 kg) were observed over time. Waist circumference, sagittal diameter, and trunk fat decreased significantly over time without group differences. Both groups significantly decreased energy intake while maintaining protein intake. Strength significantly increased over time in both groups. No changes over time or between groups were observed in hormone levels. These data suggest that yogurt supplementation offered no added benefit for increasing lean mass when combined with resistance training and modest energy restriction.
... Interventions combining resistance exercise and increased dairy consumption on body composition in premenopausal women are limited in number [5,21]. A recent 12-week weight loss trial incorporating resistance training and aerobics [5] compared 4 supplement groups: calcium supplementation (calcium lactate or phosphate), skim milk, or placebo. ...
... There was no greater fat loss among women increasing their calcium intake compared with placebo. In comparison, White et al. [21] studied the effect of 3 supplemental yogurt servings per day in young women during resistance training for 8 weeks. Participating women reported a habitual calcium intake 800 mg per day. ...
... The results of the change in body composition between LOW and HIGH groups are similar to a recent 8-week resistance training study by White et al. [21]. They reported differences between high dairy calcium and low calcium groups in weight and body composition [21]. ...
Article
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To examine the combined treatment effect of a mild energy restriction, high dairy calcium intake, and resistance exercise on promoting favorable body composition changes in overweight women with a low dairy intake. Combined treatment strategies may produce synergistic effects on increasing fat loss and preserving bone in a population at risk for obesity and osteoporosis. Overweight, sedentary women consuming a diet low in dairy calcium (≤1 serving of dairy per day) were randomized either (1) to maintain a low-calcium diet (LOW; ≤ 500 mg; n = 15) or (2) to increase dairy calcium (HIGH; ≥1200 mg; n = 14) for 16 weeks. Both groups began resistance training 3 days per week and received dietary counseling to reduce energy intake by 250 kcal per day. Body composition was measured at the beginning and at the end of the study with dual energy x-ray absorptiometry. Two 24-hour dietary recalls were measured at baseline, midpoint, and end of study with Nutrition Data System for Research software. Participants were 36.8 ± 4.8 years of age, with an average body mass index of 29.1 ± 2.1 kg/m2. Fat mass decreased significantly over time (LOW = 3.8 ± 4.1 kg and HIGH = 1.8 ± 2.1 kg) but was not significantly different by group. Mean energy reduction from baseline was 382 kcal (LOW) and 214 kcal (HIGH; p = 0.14). When change in energy intake was included as a covariate, there was still no significant difference in fat loss between groups. Change in lumbar spine bone mineral density (LOW = -1.5% and HIGH = 0.8%) was significant between groups (p = 0.02). The prescribed mean calcium intake was achieved for each study group (LOW = 454 ± 143 mg and HIGH = 1312 ± 183 mg), with no significant changes in protein intake over time (LOW = 0.9 g/kg and HIGH = 1.0 g/kg, p = 0.08). These results suggest that increasing dairy calcium offers no added benefit in reducing body fat when combined with resistance training and energy restriction. However, increasing dairy calcium improves bone mineral density in premenopausal overweight women.
... To date, only regular yogurt but not GY has been studied in combination with exercise for strength, muscle and body composition. One study in young, normal weight, untrained females indicated no further benefit of regular yogurt (5 g protein/serving, 3x/day) plus RT on increasing strength and lean mass compared to a protein-matched control and a CHO control (26). In addition, only 2 studies using regular yogurt (5 g protein/serving, 2-3 servings/day) in a weight loss context have been conducted, and results on body composition were inconclusive (23). ...
... Our research supports previous findings in young, untrained adults where milk and RT was shown to increase strength greater than a CHO placebo (12,13). However, some training studies that utilize different whole dairy foods like chocolate milk (17) or regular yogurt (26) showed no additional strength increases compared to a CHO placebo. This may be because the amount of protein provided in the aforementioned studies was insufficient to see divergent strength adaptations between the groups. ...
Article
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Milk and/or whey protein plus resistance exercise (RT) increase strength and muscle size, and optimize body composition in adult males and females. Greek yogurt (GY) contains similar muscle-supporting nutrients as milk yet it is different in several ways including being a semi-solid food, containing bacterial cultures and having a higher protein content (mostly casein) per serving. GY has yet to be investigated in the context of a RT program. The purpose of this study was to assess the effects of GY consumption plus RT on strength, muscle thickness and body composition in lean, untrained, university-aged males. Thirty untrained, university-aged (20.6 ± 2.2 years) males were randomized to 2 groups (n = 15/group): fat-free, plain GY or a Placebo Pudding (PP; isoenergetic carbohydrate-based pudding) and underwent a combined RT/plyometric training program 3 days/week for 12 weeks. They consumed either GY (20 g protein/dose) or PP (0 g protein/dose) daily, 3 times on training days and 2 times on non-training days. After 12 weeks, both groups significantly increased strength, muscle thickness and fat-free mass (FFM) (p < 0.05). The GY group gained more total strength (GY; 98 ± 37 kg, PP; 57 ± 15 kg), more biceps brachii muscular thickness (GY; 0.46 ± 0.3 cm, PP; 0.12 ± 0.2 cm), more FFM (GY; 2.4 ± 1.5 kg, PP; 1.3 ± 1.3 kg), and reduced % body fat (GY; −1.1 ± 2.2%, PP; 0.1 ± 2.6%) than PP group (p < 0.05 expressed as absolute change). Thus, consumption of GY during a training program resulted in improved strength, muscle thickness and body composition over a carbohydrate-based placebo. Given the results of our study, the general benefits of consuming GY and its distinctiveness from milk, GY can be a plausible, post-exercise, nutrient-rich alternative for positive strength, muscle, and body composition adaptations.
... So, physical activity plays an important role in the development and maintenance of bone mass and density. Peak of the force is an important and decisive factor in the analysis of mechanical load to the bone [13,14]. ...
... The participants in the milk consumption and concurrent training-milk consumed 500 ml of daily milk for 10 weeks [14]. The milk consumption and training group and the milk consumption group drank milk immediately (250 ml) and one hour after training (250 ml). ...
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Background: Osteoporosis is a skeletal metabolic disorder characterized by low bone mineral density (BMD) and reduced bone strength leading to higher bone fractures risk. The present study attempted to investigate the effects of concurrent training (aerobic-resistance) and milk consumption on some markers of BMD in women with osteoporosis. Methods: For this purpose, forty women diagnosed with osteoporosis within an age range of 30-45 years were divided into four groups of ten including concurrent training-milk, concurrent training, milk consumption and control group. The concurrent exercises were performed in ten weeks with three sessions in each week including aerobic training (running at 55-75% of maximum heart rate) and resistance training (4 move in a circle performed two times with 10 repetition maximum (RM)). Milk consumption was two times of 250 ml per day in ten weeks. Before and after treatment, BMDs in the hip and lumbar spine area were estimated with Dual-energy X-ray absorptiometry (DEXA) device and 5 cc blood was taken from a vein in the arm to determine the blood levels of 25-hydroxyvitamin D (25OH-D) and alkaline phosphatase (ALP). Results: Based on the results, blood levels 25OH-D and ALP significantly increased in concurrent training-milk, concurrent training and milk group with higher increase in concurrent training-milk group (P < 0.05). Furthermore, the right and left hip BMD in concurrent training-milk and concurrent training groups increased significantly with higher increase in concurrent training-milk group (p < 0.05). Also, lumbar spine BMD increased significantly in concurrent training-milk and concurrent training (p < 0.05). Conclusions: It seems that combination of concurrent training and milk consumption has more efficient impacts on the BMD of young women diagnosed with osteoporosis compared to the milk or concurrent training groups alone. This treatment can be used as an effective way to improve BMD in young women with diagnosed osteoporosis.
... , Erskine et al. (2012), Veillevoye et al. (2010), Weisgarber et al. (2012), Bembem et al. (2010),Kukuljan et al. (2009),Rankin et al. (2004) White et al. (2009), failed to show any difference between groups or both groups showed improvement. Due to many studies utilizing untrained subjects it may be difficult to differentiate the effects of the resistance training protocols benefits from those of the supplementation alone. ...
... Research by Miekle et al. (2009), Wilouby et al. (2007), Rozenek, Ward, Long, and Garhammer (2002), and White et al. (2009) all utilized the technique of hydrostatic weighing in which subjects are submerged in a known quantity of water and based on Archimedes principal and known standards, the practitioner can calculate the body composition of the subject. Outcomes from these studies were mixed with some finding benefits Wilouby et al. (2007) and others finding no statistically significant changes Miekle et al. (2009),Rozenek et al. (2002),White et al., (2009). Finally, in a study byGoddard, Williamson, and Trappe, (2002), the researchers utilized computerized tomography in order to compare the effects of EAA supplementation vs fructose and failed to demonstrate and significant changes in cross-sectional area. ...
Thesis
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The purposes of this dissertation were to examine the effect of a protein and carbohydrate recovery beverage versus a placebo on weightlifting performance, its effect on muscle morphological changes and specific muscle protein accretion. The following are major finding from the dissertation: 1) Protein and carbohydrate recovery supplementation does not appear to have influence on performance measure in trained weightlifters. This finding may be associated with the short-term nature of this study and the trained population used. 2) Compared with placebo, a protein and carbohydrate beverage provided greater benefits on cross sectional area of type I and type II muscle fibers. Additionally, the block periodization protocol incorporating phase potentiation improved cross sectional area of both groups compared to baseline. 3) Finally, protein and carbohydrate supplementation provided greater benefits on total mTOR and myosin heavy chains 6 & 7. These findings indicate that a protein and carbohydrate beverage provide greater benefits compared with a placebo on cellular signaling, myosin heavy gene expression and muscle fiber increases in trained weightlifters. Improved cross sectional area and increased myosin heavy chains indicate positive adaptations to resistance training combined with supplementation and may indicate improved skeletal muscle qualities necessary for increased power output. The mTOR pathway is the master regulator of cellular growth and increases in total mTOR indicate a greater proclivity for cellular growth and greater activity resulting from resistance training may increase synthesis and accretion of muscle contractile proteins. This dissertation highlighted several benefits of recovery supplementation, however further longitudinal studies utilizing block periodization and well-trained athletes are necessary to fully elucidate benefits for strength and power athletes.
... These results were contrary to our hypothesis. They are, however, in agreement with a number of reports in the literature on both young and older adults that did not demonstrate additional benefits of protein supplementation in various forms (amino acids, yogurt, milk) during RT on body composition ( Burk et al., 2009;Fiatarone et al., 1994;Godard, Williamson, & Trappe, 2002;Iglay, Thyfault, Apolzan, & Campbell, 2007;Kukuljan et al., 2009;Rankin et al., 2004;Thomas et al., 2011;Verdijk et al., 2009;Volek et al., 2003;White, Bauer, Hartz, & Baldridge, 2009). ...
... We observed no significant effect of increased calcium intake in combination with RT on changes in FM, which is consistent with the only other study on milk consumption during RT in adolescents ( Volek et al., 2003), as well as with studies in other age groups of both men and women ( Kukuljan et al., 2009;Rankin et al., 2004;Thomas et al., 2011;White, Bauer, et al., 2009). It has been suggested that the impact of dairy calcium on FM is enhanced in individuals with low baseline calcium intake ( Major et al., 2009;Tremblay & Gilbert, 2011;Wagner et al., 2007). ...
Article
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Fluid milk consumed in conjunction with resistance training (RT) provides additional protein and calcium, which may enhance the effect of RT on body composition. However, the literature on this topic is inconsistent with limited data in adolescents. Therefore, we examined the effects of a supervised RT program (6 mo, 3 d/wk, 7 exercises, 40-85% 1-repetition maximum) with daily milk supplementation (24 oz/day, one 16-oz dose immediately post-RT) on weight, fat mass (FM), and fat-free mass (FFM) assessed via dual-energy X-ray absorptiometry (baseline, 3 mo, 6 mo) in a sample of middle-school students who were randomly assigned to 1 of 3 supplement groups: milk, isocaloric carbohydrate (100% fruit juice), or water (control). Thirty-nine boys and 69 girls (mean age = 13.6 yr, mean BMI percentile = 85th) completed the study: milk n = 36, juice n = 34, water n = 38. The results showed no significant differences between groups for change in body weight (milk = 3.4 ± 3.7 kg, juice = 4.2 ± 3.1 kg, water = 2.3 ± 2.9 kg), FM (milk = 1.1 ± 2.8 kg, juice = 1.6 ± 2.5 kg, water = 0.4 ± 3.6 kg), or FFM (milk = 2.2 ± 1.9 kg, juice = 2.7 ± 1.9 kg, water = 1.7 ± 2.9 kg) over 6 mo. FFM accounted for a high proportion of the increased weight (milk = 62%, juice = 64%, water = 74%). These results from a sample of predominantly overweight adolescents do not support the hypothesis that RT with milk supplementation enhances changes in body composition compared with RT alone.
... How-ever, there is conflicting evidence for the proposed surplus benefits of dietary protein supplementation on the increase in muscle mass and strength during prolonged resistance-type exercise training. Whereas some studies report greater gains in fat-free mass (FFM) 4 , muscle fiber size, and/or muscle strength after protein supplementation during prolonged resistance-type exercise training (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), others (16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34) failed to confirm such benefits. The apparent discrepancy in the literature may be attributed to the numerous differences in study design variables, including, but not limited to, duration of the exercise intervention, training status, age of the population studied, and the amount, type, and timing of protein supplementation. ...
... Although all eligible studies in this meta-analysis shared a common directive, several studies examined slightly different hypotheses. Three studies compared the effect of supplementing different protein sources compared with a placebo on the adaptive response to prolonged exercise training (5,7,20), whereas one study compared the timing of protein supplementation on the adaptive response to prolonged exercise training (29). In these studies, the various groups receiving different protein supplements or protein at different time points were merged to form a single group and then compared with the placebo group. ...
Article
Background: Protein ingestion after a single bout of resistance-type exercise stimulates net muscle protein accretion during acute postexercise recovery. Consequently, it is generally accepted that protein supplementation is required to maximize the adaptive response of the skeletal muscle to prolonged resistance-type exercise training. However, there is much discrepancy in the literature regarding the proposed benefits of protein supplementation during prolonged resistance-type exercise training in younger and older populations. Objective: The objective of the study was to define the efficacy of protein supplementation to augment the adaptive response of the skeletal muscle to prolonged resistance-type exercise training in younger and older populations. Design: A systematic review of interventional evidence was performed through the use of a random-effects meta-analysis model. Data from the outcome variables fat-free mass (FFM), fat mass, type I and II muscle fiber cross-sectional area, and 1 repetition maximum (1-RM) leg press strength were collected from randomized controlled trials (RCTs) investigating the effect of dietary protein supplementation during prolonged (>6 wk) resistance-type exercise training. Results: Data were included from 22 RCTs that included 680 subjects. Protein supplementation showed a positive effect for FFM (weighted mean difference: 0.69 kg; 95% CI: 0.47, 0.91 kg; P < 0.00001) and 1-RM leg press strength (weighted mean difference: 13.5 kg; 95% CI: 6.4, 20.7 kg; P < 0.005) compared with a placebo after prolonged resistance-type exercise training in younger and older subjects. Conclusion: Protein supplementation increases muscle mass and strength gains during prolonged resistance-type exercise training in both younger and older subjects.
... Given that milk and whey robustly increase muscle protein synthesis in the acute setting, it is important to investigate whether this effect translates into longer-term phenotypic changes, i.e. greater lean (muscle) mass gains. Five studies, four carried out in women only and one in a mixed sample, under conditions of weight maintenance or mild energy deficit (–250 kcal/day [31]), combined resistance exercise with milk, yogurt, whey protein, or a milk-like supplement for durations ranging from 6 to 24 weeks [6,31323334. As previously mentioned, whey protein provides all of the essential amino acids that are required for muscle protein synthesis [3, 26] . ...
... Due to its generally pleasant taste, and ease of consumption and digestion, it is an attractive way to provide the body with high-quality dairy post-resistance exercise . Despite this, only two studies of 8 [34] and 16 [31] weeks' duration have utilized yogurt (6 oz) as a post-exercise supplement, and both failed to demonstrate greater increases in lean mass compared to an isoenergetic carbohydrate-containing control. However, the yogurt supplements in both studies contained only 5 g of dairy protein , which is an amount that is substantially less than what is thought to be required (i.e. ...
Article
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Resistance exercise (RE) preceding the provision of high-quality dairy protein supports muscle anabolism. Milk contains bioactive components, including two high-quality protein fractions, calcium and vitamin D, each of which has been shown modulate body composition (increasing lean mass and decreasing fat mass) under energy balance and hypoenergetic conditions. These dairy nutrients are also essential for skeletal health. Acutely, no study of RE and milk/whey consumption has been undertaken exclusively in female athletes, let alone women, nevertheless, studies with both men and women show increased lean mass accretion following milk/whey compared to soy/placebo. Currently, no longer-term RE studies with milk supplementation have been done in female athletes. However, trials in young recreationally active women demonstrated augmented increases in lean mass and decreases in fat mass with RE and milk or whey protein consumption. The amount of protein consumed post-exercise is also important; two trials using yogurt (5 g protein/6 oz) failed to demonstrate a positive change in body composition compared to placebo. For bone health, RE plus dairy improved bone mineral density at clinically important sites and reduced bone resorption. With energy restriction, in one study, higher dairy plus higher protein resulted in greater fat loss, lean mass gain and improved bone health in overweight women. In another study, milk and calcium supplementation showed no greater benefit. Neither trial exclusively utilized RE. Overall, RE and milk/dairy consumption positively impact body composition in women by promoting losses in fat, gains or maintenance of lean mass and preservation of bone. Future studies in female athletes and under energy restriction with RE alone are warranted.
... For example, women aged 26-35 participate in sports for leisure and in order to accompany their family [21][22][23][24][25]. The top three reasons why women aged 36-45 participate in sports are to strengthen their health [26,27], relieve stress, and accompany their families [28][29][30][31]. Women aged 46-50 mainly participate in sports to strengthen their health, to accompany their families, and to prevent diseases [32][33][34][35][36]. ...
Article
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The “Healthy China 2030” plan states that it is necessary to formulate and implement physical health intervention plans for special groups, including women. Based on questionnaire data from women in seven Chinese cities, our research analyzed the status quo of women’s fitness, its influencing factors, and the differences in and characteristics of different types of women’s fitness demands from four aspects: demography, fitness motivation, fitness behavior, and fitness demands, so as to provide a reference for the promotion of women’s fitness. A total of 3473 valid samples were completed. The questionnaire included five age groups: there were 146 in the “20–29 years old” group, 829 in the “30–39 years old” group, 1088 in the “40–49 years old” group, 1105 in the “50–59 years old” group and 305 in the “60 years old and above” group. The questionnaire used in this study was a self-made questionnaire. The contents of the questionnaire included age, occupation, educational level, family circumstances, and health status, women’s fitness behavior, fitness motivation and fitness demands. The results show that the current situation of urban women’s fitness in China is characterized by low frequency and short duration of exercise. The internal factors affecting women’s fitness demands include fitness motivation and fitness behavior. The external factors affecting their fitness demands are social environment and family environment. The differences in women’s fitness demands mainly come from women’s occupation, monthly income, and family stage.
... One recent study also assessed the effect of dairy consumption and resistance exercise in young women. The women consumed three servings per day of low-fat yogurt, a product with equal protein and no calcium or vitamin D, or a carbohydrate control of equal calories devoid of protein, calcium, and vitamin D (37). After 8 wk of resistance training, subjects gained lean mass and lost fat mass, but there were no significant differences between groups. ...
... Cardiorespiratory fitness (VO 2 max) also increased in these four women by a modest 8%. Our findings for the IG were similar to previous studies that observed the effects of dairy (fermented and non-fermented) supplementation in reduction of body fat in pre-and post-menopausal women and found fermented-dairy intake resulted in increased body fat loss [12][13][14][15]. High protein fermented dairy or yogurt supplementation after performing moderately intense weight-bearing and aerobic exercise may reduce body fat and increase LBM. ...
... Women in the 8-week high kefir and milk diets lost significantly more weight, BMI and WC than those in the control group, but kefir did not cause any additional weight loss than milk. Similarly, yoghurt intake was not superior in a study by White et al. (2009). Despite the well-documented benefits of yoghurt and fermented dairy products in observational studies, direct comparison of probiotic vs nonprobiotic dairy foods on BW and body composition is very limited and variation in the type of probiotic strain or the administered dose could partly explain the inconsistency between the intervention studies. ...
Chapter
The prevalence of obesity has reached epidemic proportions globally, and the trend is especially alarming in children and adolescents. Dairy products provide a range of nutrients that are important to health but contribute to overconsumed nutrients such as fat and saturated fat. Data from existing reviews on the role of dairy products in the development of obesity in childhood and adulthood are inconsistent. This chapter reviews the totality of evidence and the justification for the current approach of limiting dairy in the diet to reduce or prevent obesity or weight gain. The majority of data available from longitudinal and intervention studies in adults provide evidence of neutral associations between intakes of milk and other dairy products, and body weight and adiposity measures. Similar results were found for children and adolescents, while there is limited data for older adults. Although the mechanisms have not been clearly elucidated, they include effects on energy and fat balance, fatty acid absorption, appetite, and the metabolic activity of gut microbiota. In conclusion, although inconsistencies exist, there is little evidence to support the justification for limiting dairy in the diet on the grounds that they may promote obesity.
... However, these findings may be questioned due to very small differences in protein intake between controls and protein groups. Moreover, several studies fail to show any significant effect of protein supplementation combined with resistance training [28][29][30][31]. The discrepancy in the literature may be caused by several factors such as the design of the resistance training program, the dietary habits of subjects, supplementation doses, timing and quality, training status, length of study, and sample size. ...
Article
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During prolonged resistance training, protein supplementation is known to promote morphological changes; however, no previous training studies have tested the effect of insect protein isolate in a human trial. The aim of this study was to investigate the potential effect of insect protein as a dietary supplement to increase muscle hypertrophy and strength gains during prolonged resistance training in young men. Eighteen healthy young men performed resistance training four day/week for eight weeks. Subjects were block randomized into two groups consuming either an insect protein isolate or isocaloric carbohydrate supplementation within 1 h after training and pre-sleep on training days. Strength and body composition were measured before and after intervention to detect adaptions to the resistance training. Three-day weighed dietary records were completed before and during intervention. Fat- and bone- free mass (FBFM) improved significantly in both groups (Mean (95% confidence interval (CI))), control group (Con): (2.5 kg (1.5, 3.5)p <0.01), protein group (Pro): (2.7 kg (1.6, 3.8)p <0.01) from pre- to post-. Leg and bench press one repetition maximum (1 RM) improved by Con: (42.0 kg (32.0, 52.0)p <0.01) and (13.8 kg (10.3, 17.2)p <0.01), Pro: (36.6 kg (27.3, 45.8)p <0.01) and (8.1 kg (4.5, 11.8)p <0.01), respectively. No significant differences in body composition and muscle strength improvements were found between groups. In young healthy men, insect protein supplementation did not improve adaptations to eight weeks of resistance training in comparison to carbohydrate supplementation. A high habitual protein intake in both Con and Pro may partly explain our observation of no superior effect of insect protein supplementation.
... Although a number of studies have shown no effect of added protein/AA supplementation (169,(178)(179)(180)(181)(182)(183)(184)(185)(186)(187)(188)(189)(190)(191), other studies with a high-quality protein supplement during RET occasionally showed improved lean mass and, more infrequently, strength compared with no protein supplementation (182,(192)(193)(194)(195)(196)(197)(198). The reasons for the confusion in the literature have been suggested to stem from differences in study design, choice and measurement of outcomes, target populations, exercise protocols and timing, and the type and amount of the protein supplement or placebo given. ...
Article
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The goal of this critical review is to comprehensively assess the evidence for the molecular, physiologic, and phenotypic skeletal muscle responses to resistance exercise (RE) combined with the nutritional intervention of protein and/or amino acid (AA) ingestion in young adults. We gathered the literature regarding the translational response in human skeletal muscle to acute exposure to RE and protein/AA supplements and the literature describing the phenotypic skeletal muscle adaptation to RE and nutritional interventions. Supplementation of protein/AAs with RE exhibited clear protein dose-dependent effects on translational regulation (protein synthesis) through mammalian target of rapamycin complex 1 (mTORC1) signaling, which was most apparent through increases in p70 ribosomal protein S6 kinase 1 (S6K1) phosphorylation, compared with postexercise recovery in the fasted or carbohydrate-fed state. These acute findings were critically tested via long-term exposure to RE training (RET) and protein/AA supplementation, and it was determined that a diminishing protein/AA supplement effect occurs over a prolonged exposure stimulus after exercise training. Furthermore, we found that protein/AA supplements, combined with RET, produced a positive, albeit minor, effect on the promotion of lean mass growth (when assessed in >20 participants/treatment); a negligible effect on muscle mass; and a negligible to no additional effect on strength. A potential concern we discovered was that the majority of the exercise training studies were underpowered in their ability to discern effects of protein/AA supplementation. Regardless, even when using optimal methodology and large sample sizes, it is clear that the effect size for protein/AA supplementation is low and likely limited to a subset of individuals because the individual variability is high. With regard to nutritional intakes, total protein intake per day, rather than protein timing or quality, appears to be more of a factor on this effect during long-term exercise interventions. There were no differences in strength or mass/muscle mass on RET outcomes between protein types when a leucine threshold (>2 g/dose) was reached. Future research with larger sample sizes and more homogeneity in design is necessary to understand the underlying adaptations and to better evaluate the individual variability in the muscle-adaptive response to protein/AA supplementation during RET.
... But in the present study, according to the sporting history of study participants, and given that not exercised women have half the strength in the upper body and about 2-3 times more in lower body compared to not exercised male competitor, so the possible cause of strength surge in women consuming milk, reflects more potential in women due to the more primary strength in the lower body. Also in the study of White et al., (2009) with research on changes in body composition by eating yogurt during resistance training in women with chest and crus strength test, concluded that subjects in yogurt group had more power than the carbohydrate group or proteins group. About the effect of milk and calcium supplementation on 2max vo , after the intervention it can be stated that there is no significant difference in milk (p=0.000) and calcium supplement (p=0.001) ...
Article
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This study investigated the combined training effects and milk and calcium supplement + vitamin D consumption on fat mass, strength and aerobic power vo ) 2max ( . Trained women ( 20) N  participated in a 8-wk combined – training program. The milk group consumed 2 serving of milk and calcium supplement group consumed an isocaloric product with calcium + vitamin D. Strength, body composition, calcium, Serum 25- hydroxyl vitamin D and vo ) 2max ( were measured before and after training. BF% decreased in both groups with a greater decreased in milk group. Strength in the lower body and vo ) 2max ( increased in both groups. Vitamin D and Ca increased in both groups and this increase in vitamin D was significant in milk group   0.027 P  . It can be acknowledge that milk is a suitable drink for favorable change in body composition with combined training in women.
... The ratio of relative abundance of Bacteroidetes and Firmicutes was previously suggested to differentiate lean and obesity types in humans (Ley et al., 2005(Ley et al., , 2006. Hildebrandt et al. (2009) reported that these changes are more associated with diet than with genetic differences, and the effects of yogurt on weight control have been reported in previous studies (Sun and Zemel, 2004;Diepvens et al., 2007;White et al., 2009). Although the mechanism(s) by which this occurs are yet to be well understood, our results suggest that bacterial community shifts are likely triggered by PFM ingestion. ...
Article
We investigated the effect of consuming probiotic fermented milk (PFM) on the microbial community structure in the human intestinal tract by using high-throughput barcoded pyrosequencing. Six healthy adults ingested 2 servings of PFM daily for 3 wk, and their fecal microbiota were analyzed before and after 3 wk of PFM ingestion period and for another 3 wk following the termination of PFM ingestion (the noningestion period). Fecal microbial communities were characterized by sequencing of the V1-V3 hypervariable regions of the 16S rRNA gene. All subjects showed a similar pattern of microbiota at the phylum level, where the relative abundance of Bacteriodetes species increased during the PFM ingestion period and decreased during the noningestion period. The increase in Bacteroidetes was found to be due to an increase in members of the families Bacteroidaceae or Prevotellaceae. In contrast to PFM-induced adaptation at the phylum level, the taxonomic composition at the genus level showed a considerable alteration in fecal microbiota induced by PFM ingestion. As revealed by analysis of operational taxonomic units (OTU), the numbers of shared OTU were low among the 3 different treatments (before, during, and after PFM ingestion), but the abundance of the shared OTU was relatively high, indicating that the majority (>77.8%) of total microbiota was maintained by shared OTU during PFM ingestion and after its termination. Our results suggest that PFM consumption could alter microbial community structure in the gastrointestinal tract of adult humans while maintaining the stability of microbiota. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
... Various long-term intervention studies have confirmed the paradigm that protein feeding in close temporal proximity to each bout of exercise augments training-induced gains in muscle mass and strength [20][21][22][23][24][115][116][117][118][119][120]. However, many other studies have been unable to confirm these surplus benefits of protein supplementation above and beyond those afforded by exercise training only [121][122][123][124][125][126][127][128][129]. We previously argued that small cohorts and differences in study design may explain this apparent discrepancy in the literature [17]. ...
Article
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Given our rapidly aging world-wide population, the loss of skeletal muscle mass with healthy aging (sarcopenia) represents an important societal and public health concern. Maintaining or adopting an active lifestyle alleviates age-related muscle loss to a certain extent. Over time, even small losses of muscle tissue can hinder the ability to maintain an active lifestyle and, as such, contribute to the development of frailty and metabolic disease. Considerable research focus has addressed the application of dietary protein supplementation to support exercise-induced gains in muscle mass in younger individuals. In contrast, the role of dietary protein in supporting the maintenance (or gain) of skeletal muscle mass in active older persons has received less attention. Older individuals display a blunted muscle protein synthetic response to dietary protein ingestion. However, this reduced anabolic response can largely be overcome when physical activity is performed in close temporal proximity to protein consumption. Moreover, recent evidence has helped elucidate the optimal type and amount of dietary protein that should be ingested by the older adult throughout the day in order to maximize the skeletal muscle adaptive response to physical activity. Evidence demonstrates that when these principles are adhered to, muscle maintenance or hypertrophy over prolonged periods can be further augmented in active older persons. The present review outlines the current understanding of the role that dietary protein occupies in the lifestyle of active older adults as a means to increase skeletal muscle mass, strength and function, and thus support healthier aging.
... The latter is in line with previous work showing that protein supplementation represents an effective dietary strategy to augment further the skeletal muscle adaptive response to more prolonged resistance-type exercise training, resulting in greater gains in skeletal muscle mass and strength [8–19]. However, many other studies have also failed to detect a surplus benefit of dietary protein supplementation on the skeletal muscle adaptive response to more prolonged resistance-type exercise training [20–38]. ...
Article
Full-text available
Dietary protein ingestion following exercise increases muscle protein synthesis rates, stimulates net muscle protein accretion, and facilitates the skeletal muscle adaptive response to prolonged exercise training. Furthermore, recent studies show that protein ingestion before and during exercise also increases muscle protein synthesis rates during resistance- and endurance-type exercise. Therefore, protein ingestion before and during prolonged exercise may represent an effective dietary strategy to enhance the skeletal muscle adaptive response to each exercise session by extending the window of opportunity during which the muscle protein synthetic response is facilitated. Protein ingestion during exercise has also been suggested to improve performance capacity acutely. However, recent studies investigating the impact of protein ingestion during exercise on time trial performance, as opposed to time to exhaustion, do not report ergogenic benefits of protein ingestion. Therefore, it is concluded that protein ingestion with carbohydrate during exercise does not further improve exercise performance when compared with the ingestion of ample amounts of carbohydrate only.
... Initial pre-screening revealed 29 potential studies that investigated nutrient timing with respect to muscular adaptations. Of these studies, 3 did not meet criteria for sufficient supplemental protein intake [28][29][30] and in another the timing of consumption was outside the defined post-workout range [31]. Thus, a total of 25 studies ultimately were deemed suitable for inclusion. ...
Article
Full-text available
Protein timing is a popular dietary strategy designed to optimize the adaptive response to exercise. The strategy involves consuming protein in and around a training session in an effort to facilitate muscular repair and remodeling, and thereby enhance post-exercise strength- and hypertrophy-related adaptations. Despite the apparent biological plausibility of the strategy, however, the effectiveness of protein timing in chronic training studies has been decidedly mixed. The purpose of this paper therefore was to conduct a multi-level meta-regression of randomized controlled trials to determine whether protein timing is a viable strategy for enhancing post-exercise muscular adaptations. The strength analysis comprised 478 subjects and 96 ESs, nested within 41 treatment or control groups and 20 studies. The hypertrophy analysis comprised 525 subjects and 132 ESs, nested with 47 treatment or control groups and 23 studies. A simple pooled analysis of protein timing without controlling for covariates showed a small to moderate effect on muscle hypertrophy with no significant effect found on muscle strength. In the full meta-regression model controlling for all covariates, however, no significant differences were found between treatment and control for strength or hypertrophy. The reduced model was not significantly different from the full model for either strength or hypertrophy. With respect to hypertrophy, total protein intake was the strongest predictor of ES magnitude. These results refute the commonly held belief that the timing of protein intake in and around a training session is critical to muscular adaptations and indicate that consuming adequate protein in combination with resistance exercise is the key factor for maximizing muscle protein accretion.
... In addition, dairy products are usually enriched with vitamin D, which could mediate the effect of calcium on body fat as shown in animal studies [31]. However, this has not been observed in human studies [32,33]. The present study did not find significant differences in body composition and serum lipids profile between the high dairy group and the high elemental calcium group. ...
Article
Epidemiologic studies have shown that a high calcium intake is related to lower body weight, fat, and serum lipids in obese individuals. However, clinical studies have shown inconclusive results. The present study was conducted to determine if dairy or calcium supplementation alters body composition or serum lipids in Puerto Rican obese adults without dietary energy restriction or exercise. A 21-wk randomized clinical trial was conducted in 30 obese adults, aged 21-50 y, with usual calcium intakes <700 mg/d. Subjects were randomly assigned to the following: high dairy (∼ 1300 mg/d of calcium from dairy products by substituting foods); high calcium (∼ 1300 mg/d of calcium; ∼ 700 mg/d from diet and 600 mg/d from a supplement); or placebo. Subjects were asked to continue their established dietary intake (except for the high dairy group) and their physical activity during the study. Body weight was measured monthly; body fat, bone, and serum lipids (total cholesterol, high-density lipoprotein, low-density lipoprotein, and triacylglycerol) were measured at baseline and at 21 wk. Pairwise differences in study endpoints among the groups were assessed using ANOVA and post-hoc analysis. Grand mean calcium intake was 1200 ± 370 (median 1187) mg/d in the high dairy group, 1171 ± 265 (median 1165) mg/d in the high calcium group, and 668 ± 273 (median 691) mg/d in the control group, which was significantly lower compared to the two treatment groups (P < 0.001). There were no significant group effects in any of the outcome variables. A high dairy or calcium diet alone did not alter body composition or serum lipids profile in a sample of Puerto Rican obese adults.
... One recent study also assessed the effect of dairy consumption and resistance exercise in young women. The women consumed three servings per day of low-fat yogurt, a product with equal protein and no calcium or vitamin D, or a carbohydrate control of equal calories devoid of protein, calcium, and vitamin D (37). After 8 wk of resistance training, subjects gained lean mass and lost fat mass, but there were no significant differences between groups. ...
Article
Full-text available
We aimed to determine whether women consuming fat-free milk versus isoenergetic carbohydrate after resistance exercise would see augmented gains in lean mass and reductions in fat mass similar to what we observed in young men. Young women were randomized to drink either fat-free milk (MILK: n = 10; age (mean +/- SD) = 23.2 +/- 2.8 yr; BMI = 26.2 +/- 4.2 kg x m(-2)) or isoenergetic carbohydrate (CON: n = 10; age = 22.4 +/- 2.4 yr; BMI = 25.2 +/- 3.8 kg x m(-2)) immediately after and 1 h after exercise (2 x 500 mL). Subjects exercised 5 d x wk(-1) for 12 wk. Body composition changes were measured by dual-energy x-ray absorptiometry, and subjects' strength and fasting blood were measured before and after training. CON gained weight after training (CON: +0.86 +/- 0.4 kg, P < 0.05; MILK: +0.50 +/- 0.4 kg, P = 0.29). Lean mass increased with training in both groups (P < 0.01), with a greater net gain in MILK versus CON (1.9 +/- 0.2 vs 1.1 +/- 0.2 kg, respectively, P < 0.01). Fat mass decreased with training in MILK only (-1.6 +/- 0.4 kg, P < 0.01; CON: -0.3 +/- 0.3 kg, P = 0.41). Isotonic strength increased more in MILK than CON (P < 0.05) for some exercises. Serum 25-hydroxyvitamin D increased in both groups but to a greater extent in MILK than CON (+6.5 +/- 1.1 vs +2.8 +/- 1.3 nM, respectively, P < 0.05), and parathyroid hormone decreased only in MILK (-1.2 +/- 0.2 pM, P < 0.01). Heavy, whole-body resistance exercise with the consumption of milk versus carbohydrate in the early postexercise period resulted in greater muscle mass accretion, strength gains, fat mass loss, and a possible reduction in bone turnover in women after 12 wk. Our results, similar to those in men, highlight that milk is an effective drink to support favorable body composition changes in women with resistance training.
Article
Due to the important roles of resistance training and protein consumption in the prevention and treatment of sarcopenia, we assessed the efficacy of post-exercise Icelandic yogurt consumption on lean mass, strength, and skeletal muscle regulatory factors in healthy untrained older males. Thirty healthy untrained older males (age = 68 ± 4 yr) were randomly assigned to Icelandic yogurt (IR; n =15, 18 g of protein) or an iso-energetic placebo (PR; n =15, 0 g protein) immediately following resistance training (3x/week) for eight weeks. Before and after training, lean mass, strength, and skeletal muscle regulatory factors (insulin-like growth factor-1 [IGF-1], transforming growth factor-beta 1 [TGF-β1], growth differentiation factor 15 [GDF15], Activin A, myostatin [MST], and follistatin [FST]) were assessed. There were group x time interactions (p < 0.05) for body mass (IR: Δ 1, PR: Δ 0.7 kg), body mass index (IR: Δ 0.3, PR: Δ 0.2 kg∙m ⁻² ), lean mass (IR: Δ 1.3, PR: Δ 0.6 kg), bench press (IR: Δ 4, PR: 2.3 kg), leg press (IR: Δ 4.2, PR: Δ 2.5 kg), IGF-1 (IR: Δ 0.5, Δ PR: 0.1 ng∙mL ⁻¹ ), TGF-β (IR: Δ −0.2, PR: Δ −0.1 ng∙mL ⁻¹ ), GDF15 (IR: Δ −10.3, PR: Δ −4.8 pg∙mL ⁻¹ ), Activin A (IR: Δ −9.8, PR: Δ −2.9 pg∙mL ⁻¹ ), MST (IR: Δ −0.1, PR: Δ −0.04 ng∙mL ⁻¹ ), and FST (IR: Δ 0.09, PR: Δ 0.03 ng∙mL ⁻¹ ), with Icelandic yogurt consumption resulting in greater changes compared to placebo. The addition of Icelandic yogurt consumption to a resistance training program improved lean mass, strength, and altered skeletal muscle regulatory factors in healthy untrained older males compared to placebo. Therefore, Icelandic yogurt as a nutrient-dense source and cost-effective supplement enhances muscular gains mediated by resistance training and consequently may be used as a strategy for the prevention of sarcopenia.
Article
Protein intake above the Recommended Dietary Allowance (RDA) and resistance training are known anabolic stimuli to support healthy aging. Specifically, protein supplementation after resistance exercise and nightly are strategies to maximize utilization of protein intake above the RDA in healthy adults. As such, the primary objective was to examine the efficacy of protein supplementation and nutritional counseling resulting in either moderate (MOD: ~1.0 g·kg ⁻¹ ·d ⁻¹ ) or higher (HIGH: ~1.6 g·kg ⁻¹ ·d ⁻¹ ) protein intake during resistance training on strength (one-repetition maximum, 1-RM; isokinetic and isometric peak torque) in healthy middle-aged adults. Exploratory analyses include diet-exercise effects on lean body mass (LBM), clinical biomarkers, gut microbiota, and diet composition. 50 middle-aged adults (age: 50 ± 8 y, BMI: 27.2 ± 4.1 kg·m ⁻² ) were randomized to either MOD or HIGH protein intake during a 10-week resistance training program (3 × week). Participants received dietary counseling and consumed either 15 g (MOD) or 30 g (HIGH) of protein from lean beef in the immediate post-exercise period and each evening. Maximal strength (1-RM) for all upper and lower body exercises significantly increased with no effect of protein intake (P<0.050). There was a main effect of time for LBM (P<0.005). Cardiovascular, renal, or glycemic biomarkers were not affected by the intervention. Gut microbiota were associated with several health outcomes (P<0.050). In conclusion, higher protein intake above moderate amounts does not potentiate resistance training adaptations in previously untrained middle-aged adults. This trial was registered at clinicaltrials.gov as NCT03029975.
Article
Objective To determine the effects of multi-ingredient protein (MIP) supplements on resistance exercise training (RT)-induced gains in muscle mass and strength compared with protein-only (PRO) or placebo supplementation. Data sources Systematic search of MEDLINE, Embase, CINAHL and SPORTDiscus. Eligibility criteria Randomised controlled trials with interventions including RT ≥6 weeks in duration and a MIP supplement. Design Random effects meta-analyses were conducted to determine the effect of supplementation on fat-free mass (FFM), fat mass, one-repetition maximum (1RM) upper body and 1RM lower body muscular strength. Subgroup analyses compared the efficacy of MIP supplementation relative to training status and chronological age. Results The most common MIP supplements included protein with creatine (n=17) or vitamin D (n=10). Data from 35 trials with 1387 participants showed significant (p<0.05) increases in FFM (0.80 kg (95% CI 0.44 to 1.15)), 1RM lower body (4.22 kg (95% CI 0.79 to 7.64)) and 1RM upper body (2.56 kg (95% CI 0.79 to 4.33)) where a supplement was compared with all non-MIP supplemented conditions (means (95% CI)). Subgroup analyses indicated a greater effect of MIP supplements compared with all non-MIP supplements on FFM in untrained (0.95 kg (95% CI 0.51 to 1.39), p<0.0001) and older participants (0.77 kg (95% CI 0.11 to 1.43), p=0.02); taking MIP supplements was also associated with gains in 1RM upper body (1.56 kg (95% CI 0.80 to 2.33), p=0.01) in older adults. Summary/conclusions When MIP supplements were combined with resistance exercise training, there were greater gains in FFM and strength in healthy adults than in counterparts who were supplemented with non-MIP. MIP supplements were not superior when directly compared with PRO supplements. The magnitude of effect of MIP supplements was greater (in absolute values) in untrained and elderly individuals undertaking RT than it was in trained individuals and in younger people. Trial registration number CRD42017081970.
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zet Obezite bir halk sağlığı problemidir ve gelişiminde enerji dengesinin yanı sıra, besinsel nedenlerin de anahtar rol oynadığı bilinmektedir. Diyet kalsiyumu ise, kemik sağlığı üzerindeki etkisinin bilinmesi yanı sıra son çalışmalarda vücut ağırlık kontrolüne etkisi üzerinde durulan bir besin öğesi olmuştur. Birçok epidemiyolojik çalışma, günlük süt ve ürünlerinin uzun süreli tüketiminin vücut ağırlık ve yağ kütlesindeki azalma ile ilişkili olduğu görüşünü savunmaktadır. Makale de bu görüşü destekleyen/desteklemeyen farklı çalışmalara yer verilmekle birlikte kalsiyumun ağırlık kontrolü üzerindeki etki mekanizması açıklanmaya çalışılmıştır. Anahtar Kelimeler: Kalsiyum; ağırlık kontrolü; obezite Calcium and weight control-Publications summaries Abstract Obesity is a public health problem. And it is known that both energy balance and nutritional factors are effective on it. The effects of dietary calcium on bone health are known however with recent studies, it has become a food item that focused on the effect on body weight control. Most epidemiyolojik studies claim that there is a relationship between long-term consumption of diary milk and milk products and the decrease of body weight and fat mass. In this article, there are different studies that support or do not support this idea. However the effect mechanism of calcium on weight control is tried to be explained.
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Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) derived dietary reference values (DRVs) for vitamin D. The Panel considers that serum 25(OH)D concentration, which reflects the amount of vitamin D attained from both cutaneous synthesis and dietary sources, can be used as a biomarker of vitamin D status in adult and children populations. The Panel notes that the evidence on the relationship between serum 25(OH)D concentration and musculoskeletal health outcomes in adults, infants and children, and adverse pregnancy-related health outcomes, is widely variable. The Panel considers that Average Requirements and Population Reference Intakes for vitamin D cannot be derived, and therefore defines adequate intakes (AIs), for all population groups. Taking into account the overall evidence and uncertainties, the Panel considers that a serum 25(OH)D concentration of 50 nmol/L is a suitable target value for all population groups, in view of setting the AIs. For adults, an AI for vitamin D is set at 15 μg/day, based on a meta-regression analysis and considering that, at this intake, the majority of the population will achieve a serum 25(OH)D concentration near or above the target of 50 nmol/L. For children aged 1–17 years, an AI for vitamin D is set at 15 μg/day, based on the meta-regression analysis. For infants aged 7–11 months, an AI for vitamin D is set at 10 μg/day, based on trials in infants. For pregnant and lactating women, the Panel sets the same AI as for non-pregnant non-lactating women, i.e. 15 μg/day. The Panel underlines that the meta-regression was done on data collected under conditions of assumed minimal cutaneous vitamin D synthesis. In the presence of cutaneous vitamin D synthesis, the requirement for dietary vitamin D is lower or may even be zero.
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Objective We performed a systematic review, meta-analysis and meta-regression to determine if dietary protein supplementation augments resistance exercise training (RET)-induced gains in muscle mass and strength. Data sources A systematic search of Medline, Embase, CINAHL and SportDiscus. Eligibility criteria Only randomised controlled trials with RET ≥6 weeks in duration and dietary protein supplementation. Design Random-effects meta-analyses and meta-regressions with four a priori determined covariates. Two-phase break point analysis was used to determine the relationship between total protein intake and changes in fat-free mass (FFM). Results Data from 49 studies with 1863 participants showed that dietary protein supplementation significantly (all p<0.05) increased changes (means (95% CI)) in: strength—one-repetition-maximum (2.49 kg (0.64, 4.33)), FFM (0.30 kg (0.09, 0.52)) and muscle size—muscle fibre cross-sectional area (CSA; 310 µm² (51, 570)) and mid-femur CSA (7.2 mm² (0.20, 14.30)) during periods of prolonged RET. The impact of protein supplementation on gains in FFM was reduced with increasing age (−0.01 kg (−0.02,–0.00), p=0.002) and was more effective in resistance-trained individuals (0.75 kg (0.09, 1.40), p=0.03). Protein supplementation beyond total protein intakes of 1.62 g/kg/day resulted in no further RET-induced gains in FFM. Summary/conclusion Dietary protein supplementation significantly enhanced changes in muscle strength and size during prolonged RET in healthy adults. Increasing age reduces and training experience increases the efficacy of protein supplementation during RET. With protein supplementation, protein intakes at amounts greater than ~1.6 g/kg/day do not further contribute RET-induced gains in FFM.
Thesis
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The age-related progressive loss of skeletal muscle mass and function, termed sarcope-nia, is associated with physical disabilities, the loss of independence, and an increased risk of developing chronic metabolic disease. Skeletal muscle satellite cells play a key role in the maintenance, regeneration and growth of muscle tissue. Therefore, age-related changes in satellite cell content and/or function have been suggested to play an important role in the etiology of sarcopenia. In this thesis, we examined the potential regulatory role of satellite cell pool size and function in relation to both acute and more prolonged muscle atrophy and hypertrophy signals in humans. In Chapter 2 of this thesis we determined muscle fiber characteristics in skeletal muscle tissue in a large group of people with ages ranging over the entire life span. We ob-served a decline in type II muscle fiber size with an increasing age. The type II muscle fiber atrophy with aging is accompanied by a muscle fiber type-specific decline in satel-lite cell content. However, the age-related reduction in type II muscle fiber size and satellite cell content can be completely reversed following prolonged resistance type exercise training in healthy elderly men. Obviously, the reduced level of physical activity may play an important role in the development of type II muscle fiber atrophy and asso-ciated changes in satellite cell content with aging. In Chapter 3 we studied the impact of reducing the level of physical activity on muscle fiber size and satellite cell content. Young adults were subjected to 2 weeks of one-legged knee immobilization by means of a full leg cast. Two weeks of single legged knee immobilization resulted in a considerable decline in both type I and type II muscle fiber size but without any changes in satellite and/or myonuclear content. Subsequently, the work in this chapter suggests that a de-cline in satellite cell content is not a mechanistic prerequisite for disuse induced muscle atrophy. Apart from satellite cell content, impairments in the satellite cell activation response to anabolic stimuli may also contribute to the development of sarcopenia. Chapter 4 and 5 introduce novel immunohistological techniques that were applied to investigate changes in satellite cell activation status in human skeletal muscle biopsy samples. Skeletal mus-cle satellite cell activation status is shown to change within 9 hours of recovery after exercise. In addition, we report that changes in satellite cell content and/or activation status occur in a muscle fiber type-specific manner during the first 24 h after a single bout of exercise. These two studies emphasize the importance of analyzing changes in satellite cell activation, proliferation and/or differentiation in a muscle fiber type-specific manner in response to various anabolic stimuli in both health and disease. Sub-sequently, in Chapter 6 we determined the time-dependent changes in type I and type II muscle fiber satellite cell content and activation status in both healthy young and elderly men in response to a single bout of resistance type exercise. In this study we demon-strate that during post-exercise recovery the increase in satellite cell content is delayed with aging and is accompanied by a blunted satellite cell activation response. This atten-uated response may be instrumental in the reduced capacity of senescent muscle to respond to prolonged resistance type exercise training. In a further attempt to unravel the different factors involved in the satellite cell re-sponse to an exercise stimulus, we also looked at the potential role of nutrition. It has been well-documented that during post-exercise recovery, dietary protein intake is essential to support the increase in myofibrillar muscle protein synthesis, thereby allow-ing net muscle protein accretion. On the other hand, for more long-term muscle adapta-tion, satellite cells are required to provide additional myonuclei to allow muscle fiber hypertrophy. In Chapter 7, we investigated whether dietary protein intake is also pre-requisite to allow a proper satellite response during recovery from a single bout of re-sistance type exercise. Here we show that an acute reduction in protein intake does not affect the increase in satellite cell content but does change the timeline of myostatin expression during 72 h of post-exercise recovery. We speculate that the altered myo-statin response may represent a compensatory response to allow muscle reconditioning to occur when dietary protein becomes available. Moving forward in the line of a combined exercise and nutritional approach, in Chapter 8 we assessed whether dietary protein ingestion prior to sleep would have a surplus benefit on the increase in skeletal muscle mass and strength following 12 weeks of re-sistance type exercise training. In a previous study from our lab we have shown that protein ingestion prior to sleep increases muscle protein synthesis rates during post-exercise overnight recovery. However, whether these acute changes in muscle protein synthesis also translate to skeletal muscle adaptation to more prolonged resistance type exercise training remained to be established. In agreement with earlier work, progres-sive resistance type exercise training resulted in an increase in skeletal muscle mass and strength in both the placebo as well as the protein supplemented group of healthy young men. However, the increase in skeletal muscle mass and strength was significantly greater in the protein supplemented group. We concluded that protein ingestion prior to sleep represents an effective dietary strategy to augment skeletal muscle mass and strength gains during prolonged resistance type exercise training in healthy young males. On the muscle fiber level, the gains in muscle mass and strength in response to the 12 weeks training program were accompanied by both type I and type II muscle fiber hy-pertrophy. It is generally believed that muscle fiber hypertrophy is initially supported by an increase in myonuclear domain size. However, the existing myonuclei can only sup-port the underlying increase in transcriptional activity to a certain extent. Subsequently, the incorporation of new, satellite cell derived myonuclei may be required to allow more extensive long-term muscle fiber growth, as was also shown in Chapter 2. In Chap-ter 9, we specifically examined whether an initial (temporary) increase in myonuclear domain size represents a crucial driving force for subsequent myonuclear accretion in response to prolonged resistance type exercise training. Therefore, the change in mus-cle fiber size, myonuclear domain size, myonuclear and satellite cell content were as-sessed at different time-points throughout 12 weeks of resistance type exercise train-ing. We show that muscle fiber hypertrophy is accompanied by a time-dependent in-crease in myonuclear and satellite cell content in response to 12 weeks of resistance type exercise training in young men. However, the exercise training induced muscle fiber hypertrophy is not accompanied by any temporary or permanent increase in myo-nuclear domain size. As such, changes in myonuclear domain size do not seem to be required to elicit myonuclear accretion and support subsequent muscle hypertrophy in healthy young males. The final chapter addresses the implications of the findings presented in this thesis, and identifies a number of key topics that need to be addressed in future research. This thesis shows that skeletal muscle satellite cells represent an important factor in exercise induced muscle fiber hypertrophy. As such, an impairment in satellite cell function dur-ing post-exercise recovery, as observed in healthy elderly men, may be a crucial factor in the development of sarcopenia, and forms a primary target for intervention strategies aimed to counteract sarcopenia and improve muscle mass and function in the elderly.
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At the dawn of the third millennium, we are confronted with a disturbing phenomenon: although global life expectancy still increases, this is not the case for healthy life expectancy! The explanation of this seemingly contradiction is mainly due to the rising prevalence of the new pandemia of chronic non-communicable diseases (NCDs). Even in low and middle income countries, the improvement in healthcare status and life expectancy is paralled by the increase of NCDs, as in all countries worldwide. Since the United Nations General Assembly held in New York in 2011, many publications have emphasized the close link between NCDs and nutrition. The NCDs epidemic forces us to reconsider the public health perspectives. Many governments, non-governmental organizations and other institutions are actively involved in educational nutrition programs and campaigns; however their efforts seldom obtain the results hoped for. It is extremely difficult to induce changes in lifestyle and behavior that have built up over a long period of time. However, it becomes urgent to adapt to our changing life-environment where traditional wisdom and intuitive choices are giving way to individual thinking and search for (often uncontrolled) information. This engenders a number of unprecedented challenges and it calls for a re-appraisal of the existing paradigms to achieve an adequate management of the upstream determinants of health instead of a (pre)dominant medical and hospital-centric approach. In the era of personalized healthcare, it is time to empower policy makers, professionals and citizens for achieving an evidence-based change in the health-disease interface and decision-making process for public health interventions. The scientific and professional society Health Technology Assessment International (HTAi) has recognized nutrition as a health technology by creating a Interest Group (IG) dedicated to research on methodologies and assessments of nutrition-related public health, while taking into account contextual factors (ethical, legal, social, organizational, economic, ...) in order to generate meaningful outcomes for establishing evidence-based health policies. This Research Topic aims to elaborate on some of the potential hurdles which have to be overcome for the sake of sustainable healthcare provisions anywhere in the world, such as shortcomings in methodological approaches, regulatory frameworks, gaps between evidence, its hierarchy and final recommendations for public health management.
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Background: The health effects of conventional yogurt have been investigated for over a century; however, few systematic reviews have been conducted to assess the extent of the health benefits of yogurt. Objective: The aim of this scoping review was to assess the volume of available evidence on the health effects of conventional yogurt. Methods: The review was guided by a protocol agreed a priori and informed by an extensive literature search conducted in November 2013. Randomized controlled trials were selected and categorized according to the eligibility criteria established in the protocol. Results: 213 studies were identified as relevant to the scoping question. The number of eligible studies identified for each outcome were: bone health (14 studies), weight management and nutrition related health outcomes (81 studies), metabolic health (6 studies); cardiovascular health (57 studies); gastrointestinal health (24 studies); cancer (39 studies); diabetes (13 studies), Parkinson's disease risk (3 studies), all-cause mortality (3 studies), skin complaints (3 studies), respiratory complaints (3 studies), joint pain/function (2 studies); the remaining 8 studies reported a variety of other outcomes. For studies of a similar design and which assessed the same outcomes in similar population groups, we report the potential for the combining of data across studies in systematic reviews. Conclusions: This scoping review has revealed the extensive evidence base for many outcomes which could be the focus of systematic reviews exploring the health effects of conventional yogurt consumption.
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Background & aims: The impact of vitamin D supplementation in overweight and obese adults during resistance training on body composition, muscle function, and glucose tolerance was investigated. Methods: Twenty-three overweight and obese (age: 26.1±4.7 y; BMI: 31.3±3.2 kg/m(2); 25-hydroxyvitamin D: 19.3±7.2 ng/mL) adults were recruited for participation in a double-blind, placebo-controlled trial. Participants were randomly divided into vitamin D (VitD, 4000 IU/d; 5 females, 5 males) and placebo (PL; 7 females, 6 males) groups. Both groups completed 12 weeks of resistance training. 25-hydroxyvitamin D, parathyroid hormone, body composition, and glucose tolerance were assessed at baseline and 12 weeks. Muscle function (strength and power) was assessed at baseline, 4, 8, and 12 weeks. Results: During the intervention, 25-hydroxyvitamin D increased and parathyroid hormone decreased in the VitD group (P<0.05). Peak power was significantly increased at 4 weeks in the VitD group only (P<0.05). Regression analysis revealed an inverse association between the change in 25-hydroxyvitamin D with the change in waist-to-hip ratio (R(2)=0.205, P=0.02). No other improvements were observed with supplementation. Conclusions: Vitamin D supplementation in overweight and obese adults during resistance training induced an early improvement in peak power, and elevated vitamin D status was associated with reduced waist-to-hip ratio. Clinical trial registration number: NCT01199926.
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Public health guidelines primarily focus on the promotion of physical activity and steady-state aerobic exercise, which enhances cardiorespiratory fitness and has some impact on body composition. However, research demonstrates that resistance exercise training has profound effects on the musculoskeletal system, contributes to the maintenance of functional abilities, and prevents osteoporosis, sarcopenia, lower-back pain, and other disabilities. More recent seminal research demonstrates that resistance training may positively affect risk factors such as insulin resistance, resting metabolic rate, glucose metabolism, blood pressure, body fat, and gastrointestinal transit time, which are associated with diabetes, heart disease, and cancer. Research also indicates that virtually all the benefits of resistance training are likely to be obtained in two 15- to 20-min training sessions a week. Sensible resistance training involves precise controlled movements for each major muscle group and does not require the use of very heavy resistance. Along with brief prescriptive steady-state aerobic exercise, resistance training should be a central component of public health promotion programs.
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Seventy-three healthy, male subjects randomly divided into 3 groups participated in a study to determine the effects of 2 high-calorie nutritional supplements on body composition, body segment circumferences, and muscular strength following a resistance-training (RT) program. In addition to their normal diets group 1 (CHO/PRO; n=26) consumed a 8.4 Mj x day(-1) (2010 kcal) high calorie, high protein supplement containing 356 g carbohydrate and 106 g protein. Group 2 (CHO; n=25) consumed a carbohydrate supplement that was isocaloric with CHO/PRO. Group 3 (CTRL; n=22) received no supplement and served as a control. All subjects were placed on a 4-day x week(-1) RT program for 8 weeks. Dietary analysis revealed no significant differences in total energy consumption or nutrients at any time in the non-supplemented diets of the 3 groups. Significant (p= or <0.05) increases in body mass (BM) and fat-free mass (FFM) were observed in CHO/PRO and CHO compared to CTRL. Mean (+/- SD) increases in BM were 3.1+/-3.1 kg and 3.1+/-2.2 kg, respectively. Fat-free mass significantly (p= or <0.05) increased 2.9+/-3.4 kg in CHO/PRO and 3.4+/-2.5 kg in CHO. Muscular strength, as measured by a one-repetition maximum in the bench press, leg press, and lat-pull down increased significantly (p= or <0.05) in all groups. No significant differences in strength measures were observed among groups following training. Results indicate that high-calorie supplements are effective in increasing BM and FFM when combined with RT. However, once individual protein requirements are met, energy content of the diet has the largest effect on body composition.
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To determine if total calcium (Ca(2+)) intake and intake of Ca(2+) from dairy sources are related to whole-body fat oxidation. : Cross-sectional study. A total of 35 (21 m, 14 f) non-obese, healthy adults (mean+/-s.d., age: 31+/-6 y; weight: 71.2+/-12.3 kg; BMI: 23.7+/-2.9 kg m(-2); body fat: 21.4+/-5.4%). Daily (24 h) energy expenditure (EE) and macronutrient oxidation using whole-room indirect calorimetry; habitual Ca(2+) intake estimated from analysis of 4-day food records; acute Ca(2+) intake estimated from measured food intake during a 24-h stay in a room calorimeter. Acute Ca(2+) intake (mg. kcal(-1)) was positively correlated with fat oxidation over 24 h (r=0.38, P=0.03), during sleep (r=0.36, P=0.04), and during light physical activity (r=0.32, P=0.07). Acute Ca(2+) intake was inversely correlated with 24-h respiratory quotient (RQ) (r=-0.36, P=0.04) and RQ during sleep (r=-0.31, P=0.07). After adjustment for fat mass, fat-free mass, energy balance, acute fat intake, and habitual fat intake, acute Ca(2+) intake explained approximately 10% of the variance in 24-h fat oxidation. Habitual Ca(2+) intake was not significantly correlated to fat oxidation or RQ. Total Ca(2+) intake and Ca(2+) intake from dairy sources were similarly correlated with fat oxidation. In backwards stepwise models, total Ca(2+) intake was a stronger predictor of 24 h fat oxidation than dairy Ca(2+) intake. Higher acute Ca(2+) intake is associated with higher rates of whole-body fat oxidation. These effects were apparent over 24 h, during sleep and, to a lesser extent, during light physical activity. Calcium intake from dairy sources was not a more important predictor of fat oxidation than total Ca(2+) intake.
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To examine the differences arising from indexing resting metabolic rate (RMR) against fat-free mass (FFM) determined using two-, three- and four-compartment body composition models. All RMR and body composition measurements were conducted on the same day for each subject following compliance with premeasurement protocols. Data were generated from measurements on 104 males (age 32.1+/-12.1 y (mean+/-s.d.); body mass 81.15+/-12.85 kg; height 179.5+/-6.5 cm; body fat 20.6+/-7.6%). Body density (BD), total body water (TBW) and bone mineral mass (BMM) were measured by hydrodensitometry, deuterium dilution and dual energy X-ray absorptiometry (DXA), respectively. These measures were used to determine two (hydrodensitometry: BD; hydrometry: TBW)-, three (BD and TBW)- and four- compartment (BD, TBW and BMM) FFM values. DXA also provided three compartment derived FFM values. RMR was measured using open circuit indirect calorimetry. Three (body fat group: lean, moderate, high) x five (body composition determination: hydrodensitometry, hydrometry, three-compartment, DXA, four-compartment) ANOVAs were conducted on FFM and RMR kJ.kg FFM(-1).d(-1). Within-group comparisons revealed that hydrodensitometry and DXA were associated with significant (P<0.001) overestimations and underestimations of FFM and RMR kJ.kg FFM(-1).d(-1), respectively, compared with four-compartment-derived criterion values. A significant interaction (P<0.001) resulted from DXA's greater deviations from criterion values in lean subjects. While hydrometric means were not significantly (P> or =0.68) different from criterion values intraindividual differences were large (FFM: -1.5 to 2.9 kg; RMR: -6.0 to 3.2 kJ.kg FFM(-1).d(-1)). The relationship between RMR kJ.kg FFM(-1).d(-1) and exercise status would best be investigated using three (BD, TBW)- or four (BD, TBW, BMM)-compartment body composition models to determine FFM. Other models either significantly underestimate indexed RMR (hydrodensitometry, DXA) or display large intraindividual differences (hydrometry) compared with four-compartment derived criterion values. Australian Research Council (small grants scheme).
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Increasing 1,25-dihydroxyvitamin D in response to low-calcium diets stimulates adipocyte Ca2+ influx and, as a consequence, stimulates lipogenesis, suppresses lipolysis, and increases lipid accumulation, whereas increasing dietary calcium inhibits these effects and markedly accelerates fat loss in mice subjected to caloric restriction. Our objective was to determine the effects of increasing dietary calcium in the face of caloric restriction in humans. We performed a randomized, placebo-controlled trial in 32 obese adults. Patients were maintained for 24 weeks on balanced deficit diets (500 kcal/d deficit) and randomized to a standard diet (400 to 500 mg of dietary calcium/d supplemented with placebo), a high-calcium diet (standard diet supplemented with 800 mg of calcium/d), or high-dairy diet (1200 to 1300 mg of dietary calcium/d supplemented with placebo). Patients assigned to the standard diet lost 6.4 +/- 2.5% of their body weight, which was increased by 26% (to 8.6 +/- 1.1%) on the high-calcium diet and 70% (to 10.9 +/- 1.6% of body weight) on the high-dairy diet (p < 0.01). Fat loss was similarly augmented by the high-calcium and high-dairy diets, by 38% and 64%, respectively (p < 0.01). Moreover, fat loss from the trunk region represented 19.0 +/- 7.9% of total fat loss on the low-calcium diet, and this fraction was increased to 50.1 +/- 6.4% and 66.2 +/- 3.0% on the high-calcium and high-dairy diets, respectively (p < 0.001). Increasing dietary calcium significantly augmented weight and fat loss secondary to caloric restriction and increased the percentage of fat lost from the trunk region, whereas dairy products exerted a substantially greater effect.
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Observational studies have shown an inverse association between dietary calcium intake and body weight, and a causal relation is likely. However, the underlying mechanisms are not understood. We examined whether high and low calcium intakes from mainly low-fat dairy products, in diets high or normal in protein content, have effects on 24-h energy expenditure (EE) and substrate oxidation, fecal energy and fat excretion, and concentrations of substrates and hormones involved in energy metabolism and appetite. In all, 10 subjects participated in a randomized crossover study of three isocaloric 1-week diets with: low calcium and normal protein (LC/NP: 500 mg calcium, 15% of energy (E%) from protein), high calcium and normal protein (HC/NP: 1800 mg calcium, 15E% protein), and high calcium and high protein (HC/HP: 1800 mg calcium, 23E% protein). The calcium intake had no effect on 24-h EE or fat oxidation, but fecal fat excretion increased approximately 2.5-fold during the HC/NP diet compared with the LC/NP and the HC/HP diets (14.2 vs 6.0 and 5.9 g/day; P < 0.05). The HC/NP diet also increased fecal energy excretion as compared with the LC/NP and the HC/HP diets (1045 vs 684 and 668 kJ/day; P < 0.05). There were no effects on blood cholesterol, free fatty acids, triacylglycerol, insulin, leptin, or thyroid hormones. A short-term increase in dietary calcium intake, together with a normal protein intake, increased fecal fat and energy excretion by approximately 350 kJ/day. This observation may contribute to explain why a high-calcium diet produces weight loss, and it suggests that an interaction with dietary protein level may be important.
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Dairy Ca intake has been shown to be superior to elemental Ca in increasing the loss of body fat during energy restriction. We questioned whether the mechanisms involved an increase in postprandial energy expenditure, fat oxidation and/or a greater lipolysis. The acute effects of different sources of Ca were examined in eight subjects, aged 47-66 years and BMI 27.6-36.1 kg/m2, in a three-way cross-over study. Subjects were randomly provided breakfast meals either low in dairy Ca and vitamin D (LD; control), high in non-dairy Ca (calcium citrate) but low in vitamin D (HC) or high in dairy Ca and vitamin D (HD). Diet-induced thermogenesis, fat oxidation rates (FOR), carbohydrate oxidation rates (COR), insulin, glucose, NEFA and glycerol were measured hourly over a 6 h postprandial period. Postprandial data were calculated as a change (Delta) from the fasting value. Results showed that DeltaNEFA was significantly different between meals (LD -1.50 (sem 0.26), HC -1.22 (sem 0.32), HD -0.94 (sem 0.27) mmol/l x 6 h; P = 0.035), with a lesser suppression following both high-Ca meals. DeltaFOR was significantly higher following the two high-Ca meals (LD -6.5 (sem 2.2), HC 2.93 (sem 2.34), HD 3.3 (sem 2.5) g x 6 h; P = 0.005), while reciprocally DeltaCOR was significantly lower. DeltaGlycerol was less suppressed following the high-Ca meals but statistical significance was not achieved. No differences in diet-induced thermogenesis, insulin or glucose were observed. Regardless of source, Ca intake acutely stimulated postprandial fat oxidation; and there was a lesser suppression of NEFA following these meals.
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Data suggest that a diet deficient in calcium is associated with higher body weight and that augmenting calcium intake may reduce weight and fat gain or enhance loss. Our aim was to determine whether calcium supplementation during a weight loss intervention affects body fat or weight loss. Data were combined from three separate 25-wk randomized, double blind, placebo-controlled trials of 1000 mg/d calcium supplementation in 100 premenopausal and postmenopausal women. The primary outcome measures were change in body weight and fat mass adjusted for baseline values. There were no significant differences in body weight or fat mass change between the placebo and the calcium-supplemented groups in the pooled analysis (adjusted mean +/- SE; body weight, placebo -6.2 +/- 0.7 vs. Ca -7.0 +/- 0.7 kg; fat mass, placebo -4.5 +/- 0.6 vs. Ca -5.5 +/- 0.6 kg), and no significant interactions of calcium supplementation with menopausal/diet status. Analysis as separate trials also found no significant differences between the placebo and the calcium groups. Calcium supplementation did not significantly affect amount of weight or fat lost by women counseled to follow a moderately restricted diet for 25 wk. Nevertheless, the magnitude and direction of the differences for group means are consistent with a hypothesized small effect.
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Specific receptors for vitamin D have been identified in human muscle tissue. Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls. We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls. In a double-blind randomized controlled trial, we studied 122 elderly women (mean age, 85.3 years; range, 63-99 years) in long-stay geriatric care. Participants received 1200 mg calcium plus 800 IU cholecalciferol (Cal+D-group; n = 62) or 1200 mg calcium (Cal-group; n = 60) per day over a 12-week treatment period. The number of falls per person (0, 1, 2-5, 6-7, >7 falls) was compared between the treatment groups. In an intention to treat analysis, a Poisson regression model was used to compare falls after controlling for age, number of falls in a 6-week pretreatment period, and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations. Among fallers in the treatment period, crude excessive fall rate (treatment - pretreatment falls) was compared between treatment groups. Change in musculoskeletal function (summed score of knee flexor and extensor strength, grip strength, and the timed up&go test) was measured as a secondary outcome. Among subjects in the Cal+D-group, there were significant increases in median serum 25-hydroxyvitamin D (+71%) and 1,25-dihydroxyvitamin D (+8%). Before treatment, mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group. In the 12-week treatment period, mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group. After adjustment, Cal+D-treatment accounted for a 49% reduction of falls (95% CI, 14-71%; p < 0.01) based on the fall categories stated above. Among fallers of the treatment period, the crude average number of excessive falls was significantly higher in the Cal-group (p = 0.045). Musculoskeletal function improved significantly in the Cal+D-group (p = 0.0094). A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49% compared with calcium alone. Over this short-term intervention, recurrent fallers seem to benefit most by the treatment. The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function.
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We have previously demonstrated an antiobesity effect of dietary Ca; this is largely mediated by Ca suppression of calcitriol levels, resulting in reduced adipocyte intracellular Ca2+ and, consequently, a coordinated increase in lipid utilization and decrease in lipogenesis. Notably, dairy Ca is markedly more effective than other Ca sources. Obese subjects were placed on balanced deficit (-500 kcal/day) diets and randomized to control (400-500 mg Ca/day; n = 16) or yogurt (1100 mg Ca/day; n = 18) treatments for 12 weeks. Dietary macronutrients and fiber were held constant at the US average. Body weight, body fat and fat distribution (by dual-energy X-ray absorptiometry), blood pressure and circulating lipids were measured at baseline and after 12 weeks of intervention. Fat loss was markedly increased on the yogurt diet (-4.43+/-0.47 vs -2.75+/-0.73 kg in yogurt and control groups; P<0.005) while lean tissue loss was reduced by 31% on the yogurt diet. Trunk fat loss was augmented by 81% on the yogurt vs control diet (P<0.001), and this was reflected in a markedly greater reduction in waist circumference (-3.99+/-0.48 vs -0.58+/-1.04 cm, P<0.001). Further, the fraction of fat lost from the trunk was higher on the yogurt diet vs control (P<0.005). Isocaloric substitution of yogurt for other foods significantly augments fat loss and reduces central adiposity during energy restriction..
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Our objective was to determine the effects of dairy consumption on adiposity and body composition in obese African Americans. We performed two randomized trials in obese African-American adults. In the first (weight maintenance), 34 subjects were maintained on a low calcium (500 mg/d)/low dairy (<1 serving/d) or high dairy (1200 mg Ca/d diet including 3 servings of dairy) diet with no change in energy or macronutrient intake for 24 weeks. In the second trial (weight loss), 29 subjects were similarly randomized to the low or high dairy diets and placed on a caloric restriction regimen (-500 kcal/d). In the first trial, body weight remained stable for both groups throughout the maintenance study. The high dairy diet resulted in decreases in total body fat (2.16 kg, p < 0.01), trunk fat (1.03 kg, p < 0.01), insulin (18.7 pM, p < 0.04), and blood pressure (6.8 mm Hg systolic, p < 0.01; 4.25 mm Hg diastolic, p < 0.01) and an increase in lean mass (1.08 kg, p < 0.04), whereas there were no significant changes in the low dairy group. In the second trial, although both diets produced significant weight and fat loss, weight and fat loss on the high dairy diet were approximately 2-fold higher (p < 0.01), and loss of lean body mass was markedly reduced (p < 0.001) compared with the low dairy diet. Substitution of calcium-rich foods in isocaloric diets reduced adiposity and improved metabolic profiles in obese African Americans without energy restriction or weight loss and augmented weight and fat loss secondary to energy restriction.
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Vitamin D supplementation is suggested to reduce the risk of falls among ambulatory or institutionalized elderly subjects. The present study was undertaken to address the reduced risk of falls and hip fractures in patients with long-standing stroke by vitamin D supplementation. Ninety-six elderly women with poststroke hemiplegia were followed for two years. Patients were randomly assigned to one of the two groups, and 48 patients received 1,000 IU ergocalciferol daily, and the remaining 48 received placebo. The number of falls per person and incidence of hip fractures were compared between the two groups. Strength and tissue ATPase of skeletal muscles on the nonparetic side were assessed before and after the study. At baseline, serum 25-hydroxyvitamin D levels were in the deficient range (<10 ng/ml) in all patients; and vitamin D treatment enhanced serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels. Vitamin D treatment accounted for a 59% reduction in falls (95% CI, 28-81%; p = 0.003). There were increases in the relative number and size of type II muscle fibers and improved muscle strength in the vitamin D-treated group. Hip fractures occurred in 4 of 48 placebo group and 0 in 48 vitamin D2 group during the 2-year study period (log-rank, p = 0.049). Vitamin D may increase muscle strength by improving atrophy of type II muscle fibers, which may lead to decreased falls and hip fractures.
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Recent evidence suggests that diets high in calcium and dairy products are associated with lower body weight, particularly lower body fat levels. The purpose of this study was to compare weight and body fat loss on a calorie-restricted, low-dairy (CR) vs. high-dairy (CR+D) diet. Fifty-four subjects (BMI 30 +/- 2.5 kg/m2, 45 +/- 6.6 years, 4 men) were randomly assigned to calorie-restricted (-500 kcal/d) low-dairy calcium (n = 29; approximately 1 serving dairy/d, 500 mg/d calcium) or high-dairy calcium (n = 25; 3 to 4 servings dairy/d, 1200 to 1400 mg/d calcium) diets for 12 months. Main outcome measures included change in weight (kilograms) and body fat (percentage). There were no significant differences between groups at baseline. At 12 months, weight and body fat loss were not significantly different. Subjects in the CR vs. CR+D conditions lost 9.6 +/- 6.5 vs. 10.8 +/- 5.9 kg (p = 0.56) and 9.0 +/- 3.8 vs. 10.1 +/- 3.6 kg body fat (p = 0.37). These findings suggest that a high-dairy calcium diet does not substantially improve weight loss beyond what can be achieved in a behavioral intervention.
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Evidence from molecular and animal research and epidemiologic investigations indicates that calcium intake may be inversely related to body weight, possibly through alterations in 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] metabolism. We tested whether energy and substrate metabolism and adipose tissue enzyme messenger RNA (mRNA) expression can be altered by dietary calcium intake in healthy, nonobese, human volunteers consuming an isocaloric diet. Twelve healthy men [age: 28 +/- 2 y; body mass index (BMI; in kg/m(2)): 25.2 +/- 06] received 3 isocaloric diets [high calcium (1259 +/- 9 mg/d), high dairy (high/high); high calcium (1259 +/- 9 mg/d), low dairy (high/low); and low calcium (349 +/- 8 mg/d), low dairy (low/low)] in a randomized crossover design. At the end of the 7-d dietary periods, 24-h energy expenditure and substrate metabolism were measured, and fat biopsy specimens were obtained to determine mRNA expression in genes involved in the lipolytic and lipogenic pathways. The 24-h energy expenditure was 11.8 +/- 0.3, 11.6 +/- 0.3, and 11.7 +/- 0.3 MJ/24 h in the high/high, high/low, and low/low conditions, respectively. Fat oxidation in these conditions was 108 +/- 7, 105 +/- 9, and 100 +/- 6 g/24 h. These differences were not statistically significant. mRNA concentrations of UCP2, FAS, GPDH2, HSL, and PPARG did not differ significantly. Serum 1,25(OH)(2)D(3) concentrations changed from 175 +/- 16 to 138 +/- 15, 181 +/- 23 to 159 +/- 19, and 164 +/- 13 to 198 +/- 19 pmol/L in the high/high, high/low, and low/low conditions, respectively, and was significantly different between the high/high and low/low conditions (P < 0.05). Altering the dietary calcium content for 7 d does not influence substrate metabolism, energy metabolism, or gene expression in proteins related to fat metabolism, despite significant changes in 1,25(OH)(2)D(3) concentrations.
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Previous studies have examined the response of muscle protein to resistance exercise and nutrient ingestion. Net muscle protein synthesis results from the combination of resistance exercise and amino acid intake. No study has examined the response of muscle protein to ingestion of protein in the context of a food. This study was designed to determine the response of net muscle protein balance following resistance exercise to ingestion of nutrients as components of milk. Three groups of volunteers ingested one of three milk drinks each: 237 g of fat-free milk (FM), 237 g of whole milk (WM), and 393 g of fat-free milk isocaloric with the WM (IM). Milk was ingested 1 h following a leg resistance exercise routine. Net muscle protein balance was determined by measuring amino acid balance across the leg. Arterial concentrations of representative amino acids increased in response to milk ingestion. Threonine balance and phenylalanine balance were both > 0 following milk ingestion. Net amino acid uptake for threonine was 2.8-fold greater (P < 0.05) for WM than for FM. Mean uptake of phenylalanine was 80 and 85% greater for WM and IM, respectively, than for FM, but not statistically different. Threonine uptake relative to ingested was significantly (P < 0.05) higher for WM (21 +/- 6%) than FM (11 +/- 5%), but not IM (12 +/- 3%). Mean phenylalanine uptake/ingested also was greatest for WM, but not significantly. Ingestion of milk following resistance exercise results in phenylalanine and threonine uptake, representative of net muscle protein synthesis. These results suggest that whole milk may have increased utilization of available amino acids for protein synthesis.
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Several factors may alter apparent resting metabolic rate (RMR) during measurement with indirect calorimetry. Likewise, numerous indirect calorimetry measurement protocols have been developed over the years, and the methodology employed could influence test results. As part of a larger project to determine the role of indirect calorimetry in clinical practice, a systematic review of the literature was undertaken to determine the ideal subject condition and test methodology for obtaining reliable measurement of RMR with indirect calorimetry. Food, ethanol, caffeine, and nicotine affect RMR for a variable number of hours after consumption; therefore, intake of these items must be controlled before measurement. Activities of daily living increase metabolic rate, but a short rest (< or =20 minutes) before testing is sufficient for the effect to dissipate. Moderate or vigorous physical activity has a longer carryover effect and therefore must be controlled in the hours before a measurement of RMR is attempted. Limited data were found regarding ideal ambient conditions for RMR testing. Measurement duration of 10 minutes with the first 5 minutes deleted and the remaining 5 minutes having a coefficient of variation <10% gave accurate readings of RMR. Individuals preparing for RMR measurement via indirect calorimetry should refrain from eating, consuming ethanol and nicotine, smoking, and engaging in physical activity for varying times before measurement. The test site should be physically comfortable and the individual should have 10 to 20 minutes to rest before measurement commences. A 10-minute test duration with the first 5 minutes discarded and the remaining 5 minutes having a coefficient of variation of <10% will give an accurate measure of RMR.
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The aim was to assess the effects of resistance training and vitamin D supplementation on physical performance of healthy elderly subjects. Ninety-six subjects, aged 70 years or more with 25 OH vitamin D levels of 16 ng/ml or less, were randomized to a resistance training or control group. Trained and control groups were further randomized to receive in a double blind fashion, vitamin D 400 IU plus 800 mg of calcium per day or calcium alone. Subjects were followed for nine months. Serum 25 OH vitamin D increased from 12.4+/-2.2 to 25.8+/-6.5 ng/ml among subjects supplemented with vitamin D. Trained subjects had significant improvements in quadriceps muscle strength, the short physical performance test and timed up and go. The latter improved more in trained subjects supplemented with vitamin D. At the end of the follow up, gait speed was higher among subjects supplemented with vitamin (whether trained or not) than in non-supplemented subjects (838+/-147 and 768+/-127 m/12 min, respectively, p=0.02). Romberg ratio was lower among supplemented controls than non-supplemented trained subjects (128+/-40% and 144+/-37%, respectively, p=0.05). In conclusion, vitamin D supplementation improved gait speed and body sway, and training improved muscle strength.
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Previous results from this laboratory suggest that a 1-year dairy intake intervention in young women does not alter fat mass. The objective of this study was to determine the impact of the 1-year dairy intervention 6 months after completion of the intervention. Previously, normal-weight young women (n = 154) were randomized to one of three calcium intake groups: control (<800 mg/d), medium dairy (1000 to 1100 mg/d), or high dairy (1300 to 1400 mg/d) for a 1-year trial (n = 135 completed). In the current study, 51 women were assessed 6 months after completion of the intervention trial. Body compositions (body fat, lean mass) were measured using DXA. Self-report questionnaires were utilized to measure activity and dietary intake (kilocalories, calcium). The high-dairy group (n = 19) maintained an elevated calcium intake (1027 +/- 380 mg/d) at 18 months compared with the control group (n = 18, 818 +/- 292; p = 0.02). Mean calcium intake over the 18 months predicted a negative change in fat mass (p = 0.04) when baseline BMI was controlled in regression analysis (model R(2) = 0.11). 25-Hydroxyvitamin D levels were correlated with fat mass at each time-point (baseline, r = -0.41, p = 0.003; 12 months, r = -0.42, p = 0.002; 18 months, r = -0.32, p = 0.02) but did not predict changes in fat mass. Dietary calcium intake over 18 months predicted a negative change in body fat mass. Thus, increased dietary calcium intakes through dairy products may prevent fat mass accumulation in young, healthy, normal-weight women.
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The dependence of the resting metabolic rate (RMR) on the fat-free mass (FFM) of temporarily fasted well-fed subjects has been studied by many researchers over the years. The results of 10 such studies yield an average linear dependence with a slope of 75 +/- 15 kJ/kg per day. In the work of Keys et al (The biology of human starvation. Minneapolis, MN: University of Minnesota Press, 1950) on semistarved subjects, however, the slope of the RMR dependence on the FFM was found to be 280 +/- 50 kJ/kg per day. The argument presented in this article is that the result derived for the large group of well-fed subjects is cross-sectional information, whereas that for the semistarved subjects is longitudinal data. The linear regression of the longitudinal data yields a negative offset term that when combined with the RMR vs FFM slope divides the FFM into active and inactive components, active tissue being that which interacts directly with oxygen. The linearity of the RMR vs FFM curve suggests that the elements of the active tissue mass are energetically similar regardless of their distribution in the body's organ systems. The active-inactive model implies that the longitudinal data results from the decrease in active tissue alone, whereas cross-sectional data for different individuals correspond to an admixture of both active and inactive tissue. For different individuals having the average RMR vs FFM slope of the semistarved subjects, it is calculated that a change in the FFM consists of about 27% active and 73% inactive tissue. A histogram of the individual longitudinal RMR vs FFM slopes for the 32 semistarved subjects yields an unexpected non-Gaussian distribution with a minimal value of 158 kJ/kg per day and a maximal value of 405 kJ/kg per day.
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The purpose of this study was to investigate the impact of dietary calcium or dairy product intake on total energy expenditure (TEE), fat oxidation, and thermic effect of a meal (TEM) during a weight loss trial. The intervention included a prescribed 500-kcal deficit diet in a randomized placebo-controlled calcium or dairy product intervention employing twenty-four 18 to 31-year-old (22.2+/-3.1 years, mean +/- s.d.) overweight women (75.5+/-9.6 kg). TEM and fat oxidation were measured using respiratory gas exchange after a meal challenge, and TEE was measured by doubly labeled water. Fat mass (FM) and lean mass (fat-free mass (FFM)) were measured by dual-energy X-ray absorptiometry. Subjects were randomized into one of these three intervention groups: (i) placebo (<800 mg/day calcium intake); (ii) 900 mg/day calcium supplement; (iii) three servings of dairy products/day to achieve an additional 900 mg/day. There were no group effects observed in change in TEE; however, a group effect was observed for fat oxidation after adjusting for FFM (P=0.02). The treatment effect was due to an increase in fat oxidation in the calcium-supplemented group of 1.5+/-0.6 g/h, P=0.02. Baseline 25-hydroxyvitamin D (25OHD) was positively correlated with TEM (R=0.31, P=0.004), and trended toward a correlation with fat oxidation (P=0.06), independent of group assignment. Finally, the change in log parathyroid hormone (PTH) was positively correlated with the change in trunk FM (R=0.27, P=0.03). These results support that calcium intake increases fat oxidation, but does not change TEE and that adequate vitamin D status may enhance TEM and fat oxidation.