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Thermic effect of food, exercise, and total energy expenditure in active females
Abstract
Objectives
Exercise and the thermic effect of food (TEF) contribute to total energy expenditure (TEE) and overall maintenance of health. The aim of this study was to determine the interaction between TEF and exercise on TEE based on meal protein content.
Design
A randomized, repeated measures study.
Methods
Ten active females, of normal body weight, participated. Preliminary maximal aerobic capacity (VO2max) was determined. Three additional testing sessions consisted of performing a 30-minute bout of exercise at 60% VO2max after consumption of a high (45% total kcal) or low (15% total kcal) protein meal, or fasted.
Results
Repeated measures ANOVA indicated a significant main effect for the feeding protocols (α = .05). The high protein meal elicited a 30.39% and 98.15% greater increase in TEF compared to the low protein meal (p = .006) and fasted state (p < .001), respectively. The low protein meal resulted in 94.34% greater TEF compared to fasted (p < .001). Combined with exercise, high protein meal TEF was significantly greater compared to fasted (p = .010) but was not significantly greater than the low protein meal (p = .122). Significant differences were not found between the low protein meal with exercise compared to fasted conditions (p = .094).
Conclusions
Findings of this study provide insight on increased TEE under acute high protein feeding conditions as compared to a low protein meal and fasted state. Combined with exercise, potential for further increases in TEE exists as a result of TEF.
... There is limited data on changes in the TEF over time [14,[43][44][45], particularly in relation to changes in metabolic rate as people are losing weight; however, this is an area that needs to be examined to better understand how diet contributes to weight loss. As exercise requires energy, research on exercise and the TEF shows changes in TEF when exercise is engaged in after eating, or when eating is engaged in after exercise [46][47][48]. ...
Background
There are large individual differences in weight loss and maintenance. Metabolic testing can provide phenotypical information that can be used to personalize treatment so that people remain in negative energy balance during weight loss and remain in energy balance during maintenance. Behavioral testing can assess the reinforcing value and change in the temporal window related to the personalized diet and exercise program to motivate people to maintain engagement in healthier eating and activity programs.
Objective
Provide an expository overview of how metabolic testing can be used to personalize weight control. Ideas about incorporating behavioral economic concepts are also included.
Methods
A broad overview of how resting metabolic rate, thermic effect of food and respiratory quotient can be used to improve weight control. Also discussed are behavioral economic principles that can maximize adherence to diet and activity protocols.
Results
Research suggests that measuring metabolic rate can be used to set calorie goals for weight loss and maintenance, thermic effect of food to increase energy expenditure, and respiratory quotient to guide macronutrient composition of the diet and maximize fat loss. Developing programs that foster a strong motivation to eat healthier and be active can maximize treatment success.
Conclusion
Incorporating metabolic measures can personalize behavioral weight loss programs, and the use of behavioral economic principles can increase the probability of adherence and long‐term success in weight control.
... Studi tentang asupan kalori telah melihat berbagai dimensi dan elemen keseimbangan energi (Dowd et al., 2012;Farooqi & O'Rahilly, 2006) Tingkat metabolisme istirahat, efek termis dari nutrisi dan latihan fisik mewakili tiga jenis konsumsi energi utama, yang semuanya dapat diukur (Binns et al., 2015). Namun, variasi individu seperti usia, jenis kelamin, dan kondisi kesehatan sering kali mempersulit proses pengukuran (Cunningham, 1991). ...
Penelitian ini bertujuan untuk menganalisis kecocokan pengukuran pengeluaran energi menggunakan accelerometer ActiGraph GT3X dan ergocycle pada aktivitas fisik terkontrol. Metode penelitian ini menggunakan desain eksperimen semu dengan melibatkan 50 mahasiswa Program Studi Ilmu Keolahragaan Universitas Pendidikan Indonesia, terdiri dari 27 laki-laki dan 23 perempuan. Pengukuran dilakukan menggunakan accelerometer yang dipasang pada pinggang partisipan, serta ergocycle dengan tiga tingkat resistansi berbeda. Hasil penelitian menunjukkan rata-rata pengeluaran kalori pada laki-laki lebih tinggi dibandingkan perempuan pada kedua metode pengukuran. Analisis korelasi mengindikasikan hubungan signifikan antara ActiGraph dan ergocycle, menunjukkan bahwa kombinasi kedua alat ini dapat memberikan estimasi energi yang lebih komprehensif. Penelitian ini juga menyoroti keunggulan masing-masing alat, yaitu fleksibilitas ActiGraph untuk aktivitas sehari-hari dan akurasi ergocycle dalam kondisi terkontrol. Kendati demikian, penelitian ini terbatas pada populasi mahasiswa dan aktivitas fisik terkontrol sehingga belum dapat digeneralisasi untuk populasi lebih luas.
... The findings of increased RT recordings from both RFD and MB thermometers due to feed intake supported the earlier observations in rats (Blessing et al., 2012) and in human beings (Hayashi et al., 2014;Binns et al., 2015). Similarly, an increase in RT in goats after exercise agreed well with the previous report in human beings (Neves et al., 2015;Butts et al., 2016). ...
The livestock health monitoring programme becomes central not only for preventing outbreak of the animal diseases, but also for ensuring the fitness of the animals that directly affecting the health of the consumers. Thus, the aim of the current study was to validate the real-time rectal temperature (RT) data of radio frequency based digital (RFD) thermometer with RT data of mercury bulb (MB) thermometer by conducting three experiments in Black Bengal goats. In experiment I, six non-pregnant Black Bengal does with a mean (±SEM) body weight of 10.93 ± 1.33 at the age of 2.25 ± 0.11 years were used to record RT for 2 h on empty stomach and 2 h after feeding at 0, 30, 60, 90 and 120 min using RFD thermometer as well as MB thermometer. In experiment II, previously selected six does were further used to record RT for 2 h before exercise and 2 h after exercise at 0, 30, 60, 90 and 120 min. In experiment III, twelve non-pregnant Black Bengal does with mean (±SEM) body weight of 15.83 ± 2.16 kg at the age of 3.61 ± 0.43 years were challenged with lipopolysaccharide (LPS) μg/kg body weight and RT was recorded at 15 min interval for 1 h prior to the administration of LPS at −60, −45, −30, 15 and 0 min (0 being the time of LPS administration) and then every 15 min interval for 5 h post LPS administration up to 300 min. Two way repeated measures analysis of variance (ANOVA) with post hoc comparisons by Bonferroni test depicted that there was no significant difference (P > 0.05) between real-time RT data recorded by RFD thermometer as well as MB thermometer before and after feeding/exercise/LPS administration. Both RFD thermometer and MB thermometer recorded increased (P < 0.05 or P < 0.001) RT due to the effect of feeding/exercise/LPS administration in experimental goats. Hence, the body temperature recordings from RFD thermometer would be acceptable and thus RFD thermometer could be used for monitoring real-time RT in goats.
... Although RMR is classically measured at rest, an exercise-induced "carry-over effect" following participation in physical activity (thermic effect of exercise, TEE) (Binns et al. 2015) is believed to exert a strong influence on RMR (Serra and Ryan 2016). Furthermore, while the influence of TEE is often considered only in the immediate, postexercise period, it appears that regular exercise participation can also have a chronic effect on RMR, even in the absence of acute exercise. ...
This study aimed to determine whether resting metabolic rate (RMR) is altered in adults with facioscapulohumeral muscular dystrophy (FSHD). Eleven people with FSHD (51 ± 12yrs, 2 females) and 11 controls (48 ± 14 yrs, 2 females) completed 1 visit, including 30-minutes of indirect calorimetry and dual-energy X-ray absorptiometry (DXA) scanning. RMR was calculated from resting oxygen consumption/carbon dioxide production; regional/whole-body fat mass and lean mass were collected from the DXA scan. Absolute RMR was 15% lower in FSHD (p = 0.04); when normalized to regional/local lean mass, no differences in RMR were observed (p > 0.05). Absolute RMR was correlated with total lean mass for all participants combined (p < 0.01, r = 0.70, males only: p < 0.01, r = 0.81) and when analyzed separately (FSHD males: p = 0.001, r = 0.92 and control males: p = 0.004, r = 0.85). Whole-body lean mass was 16% lower in FSHD and leg, arm and appendicular lean mass were lower in FSHD (p < 0.05 for all), though trunk lean mass was not (p = 0.15). Whole-body fat mass was 45% higher in FSHD, with greater leg fat mass (p = 0.01), but not trunk or arm fat mass (p > 0.05 for both). When RMR was expressed relative to lean body mass, no differences in RMR were found, indicating that the lower levels of lean mass observed in FSHD patients likely contribute to the lower absolute RMR values.
Novelty:RMR is lower among people with FSHD, as compared with controls.
The reduced RMR among people with FSHD is due to disease-related loss in muscle mass and likely related to lower physical activity and/or exercise levels.
... A sedentary lifestyle and unbalanced diet are the two main risk factors to increase chronic diseases, including arterial hypertension, type II diabetes mellitus, and metabolic syndrome that; a sum of the risk factor like as increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels [1,2]. Additionally, Total Energy Expenditure is equal to the sum of Basal Metabolic Rate, Thermic Effect of Food and energy expenditure during physical activities [3,4], also has a direct relationship with the body size and the amount of time in physical activity during 24 h [5,6]. ...
Background and aims
Precise evaluation of resting metabolic rate (RMR) is critical, especially for seniors in syndromes conditions. The study aimed to compare different methods and devices to evaluate the resting metabolic rate and assess them’ reliability in Brazilian women with metabolic syndrome.
Methods
A single-center prospective study with forty elderly postmenopausal women was performed to verify the reliability of indirect calorimetry (IC) versus Bioimpedance (BIA) on RMR fluctuations for an interval length of six months.
Results
Measurements showed a high correlation between devices at baseline [BIA vs IC, intraclass correlation coefficient (ICC) = 0.906 (0.822–0.950)]. Surprisingly, a high correlation was kept between BIA and IC after six months [BIA vs. IC, ICC = 0.909 (0.829–0.952)]. The results suggest that both BIA and IC are excellent strategies to measure RMR in elderly postmenopausal women and with metabolic syndrome.
Conclusions
However, the BIA method presents greater convenience, optimizes patients' time, and does not require prolonged fasting to obtain good reliable results compared to IC.
... For the purposes of the model, it does not matter how the metabolic rate increase is achieved, only that it occurs and is subject to rate and capacity limits. The metabolic rate cannot be arbitrarily increased in response to the signal, so its control authority to remove glucose is limited to approximately 50 grams/hour (for a nominal basal rate of ~2500 kcal/day [35]). ...
At the cellular level, metabolism refers to living cells' physical and chemical reactions that produce the energy required for life. These reactions are generally categorized as catabolic (breaking down large molecules to release energy) or anabolic (synthesizing complex molecules to store energy). Humans' very existence is intimately tied to the successful operation of these cellular metabolic processes. Despite the importance of metabolism, most people possess little insight into its function and often have a vague understanding of how dietary intake and activities impact metabolism. Historically speaking, metabolism and nutrition are relatively immature fields of study, and much of what is understood about the complex regulation of cellular metabolism and its relationship to nutrition has been gleaned in just the last half century. The metabolic processes responsible for converting dietary macronutrients into the chemical energy needed to power biochemical processes were not fully understood until early in the twentieth century, when physiologists Hans Krebs and Fritz Albert Lipmann discovered the citric acid cycle [1]. As understanding of the science behind nutrition and metabolism has evolved, so has the ability to identify and treat metabolic disorders related to dietary imbalances. Despite progress in understanding metabolism, controversies still exist regarding its basic principles, such as the virtues of a low-carbohydrate versus a low-fat diet. Furthermore, even the settled science is slow to influence public policy and health care partly because nutrition education has historically played a minor role in medical training [2]. In a 2006 study, Lincoln Laboratory has developed a novel metabolic fuel model and low-cost breath sensor for measuring, tracking, and enhancing metabolism. The model can predict key metabolic state parameters, including blood glucose levels, available glycogen stores, nutrient substrate utilization, and fat accumulation or depletion, for a given diet and activity profile. It can also predict healthy metabolic responses to a variety of dietary interventions and the onset of medical conditions, such as type 2 diabetes and excessive fat accumulation. The model suggests that the measurement of key metabolic parameters, such as respiratory quotient and energy expenditure, can provide insight into metabolic health and improvements in athletic performance and endurance. »
... High-protein diets may assist with fat mass reduction through a variety of mechanisms including enhanced resting and sleeping energy expenditure [17], elevated activity related energy expenditure, increases in non-exercise activity thermogenesis [18,19] and a greater thermic effect of feeding relative to other macronutrients [20,21]. Furthermore, it is well known that protein feeding acutely elevates muscle protein synthesis post-exercise [22][23][24][25][26][27][28][29], which in theory should result in greater muscle protein accretion over time. ...
Protein is an important component of a healthy diet and appears to be integral to enhancing training adaptations in exercising individuals. The purpose of this narrative review is to provide an evidence-based assessment of the current literature examining increases in dietary protein intake above the recommended dietary allowance (RDA: 0.8 g/kg/d) in conjunction with chronic exercise on body composition (i.e., muscle, fat and bone). We also highlight acute and chronic pre-sleep protein studies as well as the influence of exercise timing on body composition. Overall, a high-protein diet appears to increase muscle accretion and fat loss and may have beneficial effects on bone when combined with exercise. Pre-sleep protein is a viable strategy to help achieve total daily protein goals. Importantly, there appears to be no deleterious effects from a high-protein diet on muscle, fat or bone in exercising individuals.
... December 2019 | Volume 7 | Issue 4 | Page 145 experiments in rats (Blessing et al., 2012) and in human beings (Hayashi et al., 2014;Binns et al., 2015). Similarly, an increase in RT in Murrah water buffaloes after exercise agreed well with the earlier report in human beings (Neves et al., 2015;Butts et al., 2016). ...
Abstract | Real-time monitoring of body temperature in livestock for detecting the febrile condition, oestrus, heat
stress, onset of calving etc is limited. Thus, the aim was to validate real-time rectal temperature (RT) data of radio frequency
based digital (RFD) thermometer with RT data of mercury bulb (MB) thermometer in female Indian Murrah
buffaloes (Bubalus bubalis). In experiment I, six buffaloes were used to record RT for 2 h on empty stomach and 2 h
after feeding at 0, 30, 60, 90 and 120 min using RFD thermometer as well as MB thermometer. In experiment II, six
buffaloes were again used to record RT for 2 h before exercise and 2 h after exercise at 0, 30, 60, 90 and 120 min. Two
way repeated measures analysis of variance (ANOVA) with post hoc comparisons by Bonferroni test showed that there
was no significant difference (P>0.05) between RT data recorded by RFD thermometer as well as MB thermometer
throughout the monitoring period. The RT data recorded by RFD thermometer and by MB thermometer were increased
(P<0.05) following feeding and exercise in buffaloes. The results obtained in the present study suggest that the
body temperature recordings from RFD thermometer could be used for monitoring real-time RT in buffaloes.
... December 2019 | Volume 7 | Issue 4 | Page 145 experiments in rats (Blessing et al., 2012) and in human beings (Hayashi et al., 2014;Binns et al., 2015). Similarly, an increase in RT in Murrah water buffaloes after exercise agreed well with the earlier report in human beings (Neves et al., 2015;Butts et al., 2016). ...
Real-time monitoring of body temperature in livestock for detecting the febrile condition, oestrus, heat stress, onset of calving etc is limited. Thus, the aim was to validate real-time rectal temperature (RT) data of radio frequency based digital (RFD) thermometer with RT data of mercury bulb (MB) thermometer in female Indian Murrah buffaloes (Bubalus bubalis). In experiment I, six buffaloes were used to record RT for 2 h on empty stomach and 2 h after feeding at 0, 30, 60, 90 and 120 min using RFD thermometer as well as MB thermometer. In experiment II, six buffaloes were again used to record RT for 2 h before exercise and 2 h after exercise at 0, 30, 60, 90 and 120 min. Two way repeated measures analysis of variance (ANOVA) with post hoc comparisons by Bonferroni test showed that there was no significant difference (P>0.05) between RT data recorded by RFD thermometer as well as MB thermometer throughout the monitoring period. The RT data recorded by RFD thermometer and by MB thermometer were increased (P<0.05) following feeding and exercise in buffaloes. The results obtained in the present study suggest that the body temperature recordings from RFD thermometer could be used for monitoring real-time RT in buffaloes.
... Thermic effect of food (TEF) is the amount of energy expended during digestion. TEF contributes to total energy expenditure (EE), because of increases in metabolic rate as the body tries to break down food into absorbable and utilizable components (Binns, Gray, & Di Brezzo, 2015). Ex vivo amylase activation leads to increased amounts of simple sugars following starch hydrolysis (Tester et al., 2006), hence facilitating absorption and thus reducing the thermic effect requirement of food. ...
Energy bioavailability can be influenced by food matrix factors and processing conditions or treatments. In this study, the effects of endogenous sweet potato amylase enzyme activation and slurry solids content of soy‐enriched orange‐fleshed sweet potato (OFSP) porridges on in vivo energy bioavailability (energy, weight gain, and feed efficiency ratio) and porridge acceptability were determined. Fifty‐six weanling albino rats were randomly assigned to two blocks each having eight groups of seven rats. The rats were housed in individual cages in a well‐ventilated animal house. The intervention block had rats fed on activated porridges (held at 75°C for 15 min), while rats in the control block were fed on nonactivated porridges (boiled at 90–95°C for 10 min). The rats were fed for 28 days on 50 ml of porridge per rat per day. The four groups per block were each fed on porridges with varying amounts of total solids content (10%, 15%, 20%, and 25%). Weight gain, energy bioavailability, and feed efficiency ratio were determined at the end of the feeding period. Consumer acceptability of activated and nonactivated porridges at 25% solids content was determined using a nontrained human panel (n = 40). Activation of amylases did not significantly (p > .05) affect the bioavailable energy, cumulative weight gain, and feed efficiency of the rats. Increasing slurry solids content of activated and nonactivated porridges significantly (p < .05) increased feed efficiency ratio (−14.6 ± 11.7 to 102.3 ± 2.3), weight gain (−1.4 to 5.6 g ± 1.9 g), and bioavailable energy (702.8 ± 16.2 to 1242.8 ± 12.2 kcal). Activation of amylases reduced porridge viscosity but did not significantly influence the overall acceptability. This work demonstrates the opportunity of utilizing sweet potato amylases to facilitate the preparation of complementary porridges with appropriate viscosity and increased energy density.
... Of late, there is limited information on the effect of either feed intake or exercise on body temperature in animals. Previous studies have shown that body temperature increased after feed intake in rats [25] and human beings [26,27]. Few reports also depicted an increase in body temperature after exercise in human beings [28,29]. ...
Aim: Dairy cattle health monitoring program becomes vital for detecting the febrile conditions to prevent the outbreak of the animal diseases as well as ensuring the fitness of the animals that are directly affecting the health of the consumers. The aim of this study was to validate real-time rectal temperature (RT) data of radio frequency based digital (RFD) thermometer with RT data of mercury bulb (MB) thermometer in dairy cattle.
Materials and Methods: Two experiments were conducted. In experiment I, six female Jersey crossbred cattle with a mean (±standard error of the mean) body weight of 534.83±13.90 kg at the age of 12±0.52 years were used to record RT for 2 h on empty stomach and 2 h after feeding at 0, 30, 60, 90, and 120 min using a RFD thermometer as well as a MB thermometer. In experiment II, six female Jersey crossbred cattle were further used to record RT for 2 h before exercise and 2 h after exercise at 0, 30, 60, 90, and 120 min. Two-way repeated measures analysis of variance with post hoc comparisons by Bonferroni test was done.
Results: Real-time RT data recorded by RFD thermometer as well as MB thermometer did not differ (p>0.05) before and after feeding/exercise. An increase (p
... One primary mechanism behind the recommendation for increasing protein intake is that it leads to an increased release of ghrelin, resulting in a greater feeling of satiety (Frestedt 230 et al., 2008). An additional potential mechanism for the increased fat loss observed in those groups following the BD may be related to the increased protein consumption leading to an increased thermic effect of food and thermic effect of exercise in healthy, active females (Binns, Gray, & Di Brezzo, 2015). ...
The increasing interest in weight loss has seen a concurrent rise in the supplemental use of thermogenics to aid weight loss efforts. To date, the effectiveness and safety of supplemental proprietary blend thermogenics, in conjunction with high-protein energy-restricted diets have not been thoroughly evaluated. The purpose of this study was to investigate the efficacy of a low-calorie, high-protein diet with and without the concomitant use of a thermogenic supplement on body weight and body composition in apparently healthy females. Subjects were divided into three groups, Bizzy Diet+FitMiss Burn (BURN, N = 12), Bizzy Diet+Placebo (PLA, N = 13), and Control (CON, N = 14), and underwent two testing sessions separated by approximately 3 weeks. Resting blood pressure (BP), resting heart rate (RHR), clinical safety markers, body weight (BW), and body composition were assessed during each testing session. Repeated measures analysis of variance (ANOVA) revealed a significant effect for time relative to BW, total body fat mass (FM), leg FM, and trunk FM. Post hoc analysis revealed that the BURN and PLA groups experienced significant decreases in both BW and total body FM compared to CON (p <.05). There were no significant interactions for BP, RHR, or clinical safety markers over the course of the study. The Bizzy Diet, both with and without the addition of FitMiss Burn thermogenic, appears to be safe for short-term use and may lead to greater improvement in body composition and BW in an apparently healthy female population.
... Glucose utilization as a major fuel to meet metabolic demands during this bout of exercise requires phosphorus during glycogenolysis to form glucose-1-phosphate and glucose-6-phosphate potentially leading to an intracellular phosphorus flux during exercise as observed in other exercising canine studies (20,21). The reason for no dietary differences in phosphorus influx is likely due to the exercise bout being well within the range the time range for carbohydrate oxidation, which relies on either glycogenolysis and to a lesser degree protein or fat metabolism (22). In addition, the CO group had similarly lower serum phosphorus to the LF group, which might be a reflection of overall lower phosphorus in the diet due to corn oil dilution of overall phosphorus intake in this group. ...
Optimal dietary protocols for the athletic canine are often defined by requirements for endurance athletes that do not always translate into optimal dietary interventions for all canine athletes. Prior research studying detection dogs suggests that dietary fat sources can influence olfaction; however, as fat is added to the diet the protein calories can be diminished potentially resulting in decreased red blood cell counts or albumin status. Optimal macronutrient profile for detection dogs may be different considering the unique work they engage in. To study a calorically low protein: high fat (18:57% ME), high protein: high fat (27:57% ME), and high protein: low fat (27:32% ME) approach to feeding, 17 dogs were provided various diets in a 3 × 3 cross over design. Dogs were exercised on a treadmill and blood was taken pre-exercise, immediately post-exercise, 10- and 20-min post-exercise to assess complete blood count, serum chemistry, blood gases, and cortisol; as well as rectal and core body temperature. Exercise induced a decrease in serum phosphorus, potassium, and increases in non-esterified fatty acids and cortisol typical of moderate exercise bouts. A complete and balanced high protein: high-fat diet (27:57% ME) induced decreases in serum cortisol and alkaline phosphatase. Corn oil top dressed low protein: high-fat diet (18:57% ME) induced a slightly better thermal recovery than a complete and balanced high protein: high fat diet and a high protein: low fat (27%:32% ME) diet suggesting some mild advantages when using the low protein: high fat diet that warrant further investigation regarding optimal protein and fat calories and thermal recovery.
... Protein's thermic effect of feeding (TEF) is 19-23 % in both obese and lean individuals whereas carbohydrate is approximately 12-14 % [8]. A high protein diet (45 % total kcal) elicits a 30 % greater TEF than an isocaloric low protein (15 % total kcal) in active females [9]. The subjects in our study did Data are mean ± SD. n = 12 CHO carbohydrate, PRO protein, g grams, kg kilograms, d days, HP high protein, NP normal protein * P < 0.05denotes significantly different than baseline. ...
Background:
Eight weeks of a high protein diet (>3 g/kg/day) coupled with a periodized heavy resistance training program has been shown to positively affect body composition with no deleterious effects on health. Using a randomized, crossover design, resistance-trained male subjects underwent a 16-week intervention (i.e., two 8-week periods) in which they consumed either their normal (i.e., habitual) or a higher protein diet (>3 g/kg/day). Thus, the purpose of this study was to ascertain if significantly increasing protein intake would affect clinical markers of health (i.e., lipids, kidney function, etc.) as well as performance and body composition in young males with extensive resistance training experience.
Methods:
Twelve healthy resistance-trained men volunteered for this study (mean ± SD: age 25.9 ± 3.7 years; height 178.0 ± 8.5 cm; years of resistance training experience 7.6 ± 3.6) with 11 subjects completing most of the assessments. In a randomized crossover trial, subjects were tested at baseline and after two 8-week treatment periods (i.e., habitual [normal] diet and high protein diet) for body composition, measures of health (i.e., blood lipids, comprehensive metabolic panel) and performance. Each subject maintained a food diary for the 16-week treatment period (i.e., 8 weeks on their normal or habitual diet and 8 weeks on a high protein diet). Each subject provided a food diary of two weekdays and one weekend day per week. In addition, subjects kept a diary of their training regimen that was used to calculate total work performed.
Results:
During the normal and high protein phase of the treatment period, subjects consumed 2.6 ± 0.8 and 3.3 ± 0.8 g/kg/day of dietary protein, respectively. The mean protein intake over the 4-month period was 2.9 ± 0.9 g/kg/day. The high protein group consumed significantly more calories and protein (p < 0.05) than the normal protein group. There were no differences in dietary intake between the groups for any other measure. Moreover, there were no significant changes in body composition or markers of health in either group. There were no side effects (i.e., blood lipids, glucose, renal, kidney function etc.) regarding high protein consumption.
Conclusion:
In resistance-trained young men who do not significantly alter their training regimen, consuming a high protein diet (2.6 to 3.3 g/kg/day) over a 4-month period has no effect on blood lipids or markers of renal and hepatic function. Nor were there any changes in performance or body composition. This is the first crossover trial using resistance-trained subjects in which the elevation of protein intake to over four times the recommended dietary allowance has shown no harmful effects.
... Protein has a TEF of approximately 19-23 % in both obese and lean individuals whereas carbohydrate is approximately 12-14 % [19]. In fact, a high protein meal (45 % total kcal) elicits a 30 % greater TEF than an isocaloric low protein meal (15 % total kcal) in active females [20]. It should be noted that the TEF of fat is substantially less in the obese than in lean subjects [19]. ...
... Protein has a TEF of approximately 19-23 % in both obese and lean individuals whereas carbohydrate is approximately 12-14 % [19]. In fact, a high protein meal (45 % total kcal) elicits a 30 % greater TEF than an isocaloric low protein meal (15 % total kcal) in active females [20]. It should be noted that the TEF of fat is substantially less in the obese than in lean subjects [19]. ...
Background:
The consumption of a high protein diet (>4 g/kg/d) in trained men and women who did not alter their exercise program has been previously shown to have no significant effect on body composition. Thus, the purpose of this investigation was to determine if a high protein diet in conjunction with a periodized heavy resistance training program would affect indices of body composition, performance and health.
Methods:
Forty-eight healthy resistance-trained men and women completed this study (mean ± SD; Normal Protein group [NP n = 17, four female and 13 male]: 24.8 ± 6.9 yr; 174.0 ± 9.5 cm height; 74.7 ± 9.6 kg body weight; 2.4 ± 1.7 yr of training; High Protein group [HP n = 31, seven female and 24 male]: 22.9 ± 3.1 yr; 172.3 ± 7.7 cm; 74.3 ± 12.4 kg; 4.9 ± 4.1 yr of training). Moreover, all subjects participated in a split-routine, periodized heavy resistance-training program. Training and daily diet logs were kept by each subject. Subjects in the NP and HP groups were instructed to consume their baseline (~2 g/kg/d) and >3 g/kg/d of dietary protein, respectively.
Results:
Subjects in the NP and HP groups consumed 2.3 and 3.4 g/kg/day of dietary protein during the treatment period. The NP group consumed significantly (p < 0.05) more protein during the treatment period compared to their baseline intake. The HP group consumed more (p < 0.05) total energy and protein during the treatment period compared to their baseline intake. Furthermore, the HP group consumed significantly more (p < 0.05) total calories and protein compared to the NP group. There were significant time by group (p ≤ 0.05) changes in body weight (change: +1.3 ± 1.3 kg NP, -0.1 ± 2.5 HP), fat mass (change: -0.3 ± 2.2 kg NP, -1.7 ± 2.3 HP), and % body fat (change: -0.7 ± 2.8 NP, -2.4 ± 2.9 HP). The NP group gained significantly more body weight than the HP group; however, the HP group experienced a greater decrease in fat mass and % body fat. There was a significant time effect for FFM; however, there was a non-significant time by group effect for FFM (change: +1.5 ± 1.8 NP, +1.5 ± 2.2 HP). Furthermore, a significant time effect (p ≤ 0.05) was seen in both groups vis a vis improvements in maximal strength (i.e., 1-RM squat and bench) vertical jump and pull-ups; however, there were no significant time by group effects (p ≥ 0.05) for all exercise performance measures. Additionally, there were no changes in any of the blood parameters (i.e., basic metabolic panel).
Conclusion:
Consuming a high protein diet (3.4 g/kg/d) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition. Furthermore, there is no evidence that consuming a high protein diet has any deleterious effects.
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Stunting prevalence in Indonesia, including East Java Province, fell into high category and mandates public health concern. In developing countries, the possibility of stunted child can be reduced if women of reproductive age have good health and nutrition. Community health workers (CHWs), or widely known as Kader Kesehatan in Indonesia, are essential public health workforce who carry out several activities including providing nutrition education to women of reproductive age. This study aimed to assess the knowledge of Kader Kesehatan actively work in an urban village in Surabaya, Indonesia, and provided sufficient education in order to improve the knowledge of Kader Kesehatan in regards to nutrition. This study was conducted through a community development event in an urban village (kelurahan) in Surabaya, East Java, Indonesia. Fifty-two Kader Kesehatan residing and actively work with the community of the urban village were enrolled in this study. Theoretical subjects were delivered using lecture method, while technical subjects were delivered using small-group instruction method. Pre-test and post-test were administered prior and after education, respectively. Prior to the education, most Kader Kesehatan could not answer and perform anthropometric measurement correctly for all subjects related to stunting in children under five and women nutrition. Following the nutrition education, the knowledge of Kader Kesehatan was improved significantly (p<0.05). Despite the experience of working with the community, Kader Kesehatan need continuous education in order to improve their knowledge, especially about nutrition; thus, able to provide adequate education for women and helping the effort of stunting reduction in Indonesia.
Background: Visceral fat accumulation due to the decrease in estrogen levels, and gaining weight after menopause, increases the risk of metabolic syndrome and cardiovascular diseases in postmenopausal women; While physical activity at Fatmax and green tea consumption are recommended for increasing fat oxidation. Methods: 24 sedentary postmenopausal women were divided into two groups: exercise+supplemnet and exercise+placebo. Exercise tests were performed by gas analyzer device and blood samples were collected after 12 hours of fasting overnight in pre and post test phases. The supplement group had a daily intake of 1200 mg of green tea extract in capsule form. The training Protocol contained two weeks of aerobic exercise at an intensity of about maximum fat oxidation which was performed four times a week and each session took 40 to 50 minutes. Results: After two weeks, the amounts of weight, body mass index, waist to hip ratio, average total carbohydrate oxidation and HDL were significantly decreased in both groups (p≤0.05). The peak oxygen consumption, maximum fat oxidation, Fatmax and the average total fat oxidation increased but were not significant (p>0.05). Triglyceride (P=0.003) and visceral fat levels (P=0.044) only declined significantly in exercise+placebo group and LDL levels (P=0.043) only increased in exercise+supplement, significantly. Fat percentage also decreased in two groups which was not significant (p>0.05). Conclusions: Short-term aerobic exercise at Fatmax, alone and along with green tea consumption, reduced body weight and improved average total carbohydrate oxidation in sedentary postmenopausal women and aerobic exercise with green tea was more effective in reducing triglycerides and visceral fat levels.
Protein is the only dietary macronutrient required for life. As such, it is reasonable to consider dietary protein as the centerpiece of a healthy eating pattern. To do so requires consideration of what type of protein should be eaten. Account should be taken of the quality of the protein, the density of the protein in the protein food source, and the non-protein components of protein food source. The quality of protein can be quantified based on the amount and profile of essential amino acids (EAAs), as well as the true ileal digestibility of the EAAs in the protein. The density of protein in a food source can be quantified on the basis of the amount of total calories ingested to achieve intake of the daily requirement of all EAAs. Non-protein components of protein food sources can be considered in terms of the amount and nature of fat, carbohydrate and fiber, as well as the content of micronutrients. Potential beneficial effects of high-quality protein food sources should be balanced against any possible adverse effects. When all of these factors are considered we conclude that animal-based protein foods (e.g., eggs, dairy, meat, fish, poultry) occupy an important place in a healthy eating pattern.
The effects of meal size and frequency on thermic effect of food (TEF) were examined in seven healthy normal-weight young women. Each volunteer consumed in random order one of two identical meals [3138 kJ (750 kcal), 54.5% carbohydrate, 14.0% protein, 31.5% fat]. One meal was taken over 10 min [large meal (LM)] whereas the other was taken in six equal portions of 523 kJ (125 kcal) at 30-min intervals over a 3-h period [small meals (SM)]. Metabolic rate was measured for 1 h before and every 30 min after the meal started for 5 h. When expressed as either kJ/min (kcal/min) or kJ/5h (kcal/5h), TEF was significantly higher in the LM day than in the SM day (P less than 0.05). We conclude that the temporal pattern in which a mixed caloric load is eaten affects the thermogenic response and may be an important determinant of energy balance after a meal.
The thermic effect of food at rest, during 30 min of cycle ergometer exercise, and after exercise was studied in eight lean (mean +/- SEM, 10 +/- 1% body fat, hydrostatically-determined) and eight obese men (30 +/- 2% body fat). The lean and obese mean were matched with respect to age, height, weight, and body mass index (BMI) to determine the relationship between thermogenesis and body composition, independent of body weight. All men were overweight, defined as a BMI between 26-34, but the obese had three times more body fat and significantly less lean body mass than the lean men. Metabolic rate was measured by indirect calorimetry under four conditions on separate mornings, in randomized order, after an overnight fast: 3 h of rest in the postabsorptive state; 3 h of rest after a 750-kcal mixed meal (14% protein, 31.5% fat, and 54.5% carbohydrate); during 30 min of cycling and for 3 h post exercise in the postabsorptive state; and during 30 min of cycling performed 30 min after the test meal and for 3 h post exercise. The thermic effect of food, which is the difference between postabsorptive and postprandial energy expenditure, was significantly higher for the lean than the obese men under the rest, post exercise, and exercise conditions: the increments in metabolic rate for the lean and obese men, respectively, were 48 +/- 7 vs. 28 +/- 4 kcal over 3 h rest (P less than 0.05); 44 +/- 7 vs. 16 +/- 5 kcal over 3 h post exercise (P less than 0.05); and 19 +/- 3 vs. 6 +/- 3 kcal over 30 min of exercise (P less than 0.05). The thermic effect of food was significantly negatively related to body fat content under the rest (r = -0.55), post exercise (r = -0.66), and exercise (r = -0.58) conditions. The results of this study indicate that for men of similar total body weight and BMI, body composition is a significant determinant of postprandial thermogenesis; the responses of obese are significantly blunted compared with those of lean men.
No current treatment for obesity reliably sustains weight loss, perhaps because compensatory metabolic processes resist the maintenance of the altered body weight. We examined the effects of experimental perturbations of body weight on energy expenditure to determine whether they lead to metabolic changes and whether obese subjects and those who have never been obese respond similarly.
We repeatedly measured 24-hour total energy expenditure, resting and nonresting energy expenditure, and the thermic effect of feeding in 18 obese subjects and 23 subjects who had never been obese. The subjects were studied at their usual body weight and after losing 10 to 20 percent of their body weight by underfeeding or gaining 10 percent by overfeeding.
Maintenance of a body weight at a level 10 percent or more below the initial weight was associated with a mean (+/- SD) reduction in total energy expenditure of 6 +/- 3 kcal per kilogram of fat-free mass per day in the subjects who had never been obese (P < 0.001) and 8 +/- 5 kcal per kilogram per day in the obese subjects (P < 0.001). Resting energy expenditure and nonresting energy expenditure each decreased 3 to 4 kcal per kilogram of fat-free mass per day in both groups of subjects. Maintenance of body weight at a level 10 percent above the usual weight was associated with an increase in total energy expenditure of 9 +/- 7 kcal per kilogram of fat-free mass per day in the subjects who had never been obese (P < 0.001) and 8 +/- 4 kcal per kilogram per day in the obese subjects (P < 0.001). The thermic effect of feeding and nonresting energy expenditure increased by approximately 1 to 2 and 8 to 9 kcal per kilogram of fat-free mass per day, respectively, after weight gain. These changes in energy expenditure were not related to the degree of adiposity or the sex of the subjects.
Maintenance of a reduced or elevated body weight is associated with compensatory changes in energy expenditure, which oppose the maintenance of a body weight that is different from the usual weight. These compensatory changes may account for the poor long-term efficacy of treatments for obesity.
The aim of this study was to determine the effects of exercise at different intensities on 24-h energy expenditure (EE) and substrate oxidation. Sixteen adults (8 men and 8 women) were studied on three occasions [sedentary day (Con), a low-intensity exercise day (LI; 400 kcal at 40% of maximal oxygen consumption) and a high-intensity exercise day (HI; 400 kcal at 70% of maximal oxygen consumption)] by using whole room indirect calorimetry. Both 24-h EE and carbohydrate oxidation were significantly elevated on the exercise days (Con < LI = HI), but 24-h fat oxidation was not different across conditions. Muscle enzymatic profile was not consistently related to 24-h fat or carbohydrate oxidation. With further analysis, it was found that, compared with men, women sustained slightly higher rates of 24-h fat oxidation (mg x kg FFM(-1) x min(-1)) and had a muscle enzymatic profile favoring fat oxidation. It is concluded that exercise intensity has no effect on 24-h EE or nutrient oxidation. Additionally, it appears that women may sustain slightly greater 24-h fat oxidation rates during waking and active periods of the day.
The thermic effect of food (TEF) declines with advancing age in adult humans but is enhanced in the habitually exercising state. The responsiveness of the sympathetic nervous system (SNS) has been implicated in these differences in TEF. We tested the hypotheses that 1) the reduction in TEF with aging is associated with an attenuated SNS response to acute energy intake; and 2) the greater TEF observed in endurance exercise-trained adults is associated with an augmented SNS response. Four groups of healthy men were studied: 16 young and 11 older sedentary men and nine young and 10 older habitually exercising men. Metabolic rate (indirect calorimetry, ventilated hood), skeletal muscle sympathetic nerve activity (MSNA; peroneal microneurography), and plasma norepinephrine and plasma epinephrine concentrations were measured before and for up to 4 h after ingestion of a carbohydrate drink (2.5 g/kg fat-free mass). TEF was approximately 50% greater in young compared with older men (P < 0.05) and approximately 25% greater in exercising compared with sedentary men (P < 0.05). In contrast, the MSNA, plasma norepinephrine, and plasma epinephrine responses were not different among the four groups. Covarying for MSNA did not significantly alter the observed differences in TEF. Habitual exercise status did not affect the age-associated decline in TEF. These findings demonstrate that altered postprandial whole-body and skeletal muscle SNS activation is not an important mechanism mediating either the reduction in TEF with aging or the augmented TEF associated with the exercise-trained state in healthy men. Differences in beta-adrenergic responsiveness to postprandial sympathoadrenal stimulation and/or nonsympathetic adrenergic influences likely explain the age- and habitual exercise-related differences in TEF.
A new Open Access journal, Nutrition & Metabolism (N&M) will publish articles that integrate nutrition with biochemistry and molecular biology. The open access process is chosen to provide rapid and accessible dissemination of new results and perspectives in a field that is of great current interest. Manuscripts in all areas of nutritional biochemistry will be considered but three areas of particular interest are lipoprotein metabolism, amino acids as metabolic signals, and the effect of macronutrient composition of diet on health. The need for the journal is identified in the epidemic of obesity, diabetes, dyslipidemias and related diseases, and a sudden increase in popular diets, as well as renewed interest in intermediary metabolism.
The role of exercise training in energy balance has been reviewed. Recent well-conducted studies showed that exercise may increase energy expenditure not only during the period of exercise itself but during the postexercise period as well. This notion of excess postexercise oxygen consumption (EPOC), which has been a controversial issue for many years, is now becoming a generally well-accepted concept, the consensus being that EPOC takes place following prolonged and strenuous exercise bouts. Besides, the role of EPOC in long-term energy balance remains to be determined. Long-term energy balance studies carried out in rats show that exercise affects energy balance by altering food intake and promoting energy expenditure. In male rats exercise causes a marked decrease in energy intake which contributes, in association with the expenditure of exercise itself, to retard lean and fat tissue growth. From the suppressed deposition of lean body mass, decreases in basal metabolic rate can be predicted in males. In female rats, exercise does not affect food intake; the lower energy gain of exercise-trained females results from the elevated expenditure rate associated with exercise itself. In both male and female rats, there is no evidence that exercise training affects energy expenditure other than during exercise itself unless the habitual feeding pattern of the rats is radically modified. The interactive effects of diet and exercise, which have to be further investigated in long-term energy balance, emerge as a promising area of research.
The effect of energy content and protein concentration of a test meal and exercise intensity on the thermic effect of food (TEF) was examined. TEF was measured in eight men in response to meals representing 15, 30, and 45% of daily energy requirement; protein concentrations of 15, 30, and 45% of energy of the meal, and exercise intensities of 35, 50, and 65% of maximum capacity. In response to energy content of the meals, total 3-h TEF (mean +/- SEM) 4.0 +/- 0.83, 9.7 +/- 1.15, and 10.8 +/- 0.79 1 O2 for the 15, 30, and 45% meals, respectively, indicating a positive linear and a negative quadratic relationship. Although the 15% protein meal resulted in the smallest TEF, 150-270 min after the meal, total 5-h increase in oxygen consumption did not differ among the three protein meals. Exercise intensity did not alter TEF. Energy content of the test meal had the greatest effect on TEF.
Daily energy expenditure consists of three components: basal metabolic rate, diet-induced thermogenesis and the energy cost of physical activity. Here, data on diet-induced thermogenesis are reviewed in relation to measuring conditions and characteristics of the diet.
Measuring conditions include nutritional status of the subject, physical activity and duration of the observation. Diet characteristics are energy content and macronutrient composition.
Most studies measure diet-induced thermogenesis as the increase in energy expenditure above basal metabolic rate. Generally, the hierarchy in macronutrient oxidation in the postprandial state is reflected similarly in diet-induced thermogenesis, with the sequence alcohol, protein, carbohydrate, and fat. A mixed diet consumed at energy balance results in a diet induced energy expenditure of 5 to 15 % of daily energy expenditure. Values are higher at a relatively high protein and alcohol consumption and lower at a high fat consumption. Protein induced thermogenesis has an important effect on satiety.
In conclusion, the main determinants of diet-induced thermogenesis are the energy content and the protein- and alcohol fraction of the diet. Protein plays a key role in body weight regulation through satiety related to diet-induced thermogenesis.
The effects of a single meal on oxygen consumption (Vo2) before and during exercise in 6 normal men have been studied. Ingestion of 1,000 or 3,000 kcal for breakfast increased Vo2 (thermic effect) by 10%, but the larger breakfast did not induce a greater effect than the smaller one. During exercise after food ingestion, there was an additional thermic effect which had the same magnitude as the effect of food itself. The thermic effects of exercise and food ingestion were not altered in 4 subjects who ingested 4,000 extra kcal daily for 30 days or in 2 subjects who ate a high protein and a low protein diet for 2 wk periods.
1. In order to reinvestigate the classical concept of specific dynamic action of food, the thermic effect of ingested glucose (50 g) or essential amino acids (50 g) or both was measured in seven healthy male subjects dressed in shorts, by using both direct and indirect calorimetry simultaneously. Experiments were performed under conditions of thermal comfort at 28°.
2. Energy ‘balance’ (heat production minus heat losses) was negative during the control period (mean heat deficit: −16.0 ± 0.8 kJ/m ² per h.
3. Metabolic rate increased 13.6 ± 1.8% after the glucose load, 17.2 ± 1.4% after amino acids, and 17.3 ± 2.9% after both glucose and amino acids: thus there was no additive thermic effect when both nutrients were given together.
4. In contrast to the metabolic rate, heat losses were not significantly altered after nutrient ingestion; consequently, the energy ‘balance’ became rapidly positive.
5. These results show that: (a) the food-induced thermogenesis, for a moderate energy intake, is less dependent on the nature of the nutrients than was classically admitted; (b) this increased heat production mainly induces changes in heat storage rather than in heat losses during the first hours following ingestion of a meal.
The effects of intermittent exercise on increases in metabolic rate and plasma insulin, glucose, and triglyceride concentrations at 1, 2, and 3 h after an 800-kcal meal were examined in six healthy volunteers. Mean plasma insulin concentrations were significantly lower (-61%) at the end of a 15-min exercise session on a stationary bicycle (50 W) at 1 h after the meal, compared to insulin concentrations when subjects rested throughout the test, but had returned to normal resting levels by 30 min after the end of the exercise bout. Mean plasma glucose concentrations were not significantly different at the end of the exercise bouts than they were at comparable times of the resting study, but were about 20 mg/dl higher 30 min after the exercise bouts. Plasma triglyceride concentrations increased by approximately 50% after the meal, and this effect was not influenced by exercise. Resting metabolic rate increased by 19.9 +/- 2.1, 20.6 +/- 2.1, and 15.1 +/- 2.4 kcal/h at 1, 2, and 3 h after meal onset, and the metabolic rate during exercise increased by 13.8 +/- 4.4, 16.8 +/- 3.5, and 11.6 +/- 3.4 kcal/h at 1, 2, and 3 h after meal onset. These data suggest that postprandial exercise would be no more beneficial than preprandial exercise in increasing energy expenditure.
The thermic effect of food during incremental cycle ergometer exercise was compared in six normal weight and six obese men (mean +/- SEM 104 +/- 5% and 160 +/- 11% ideal body weight, respectively). Graded exercise tests were performed after a 12-h fast and 60 min after the start of a 910 kcal mixed meal, on separate days. The thermic of food during exercise, which is the fed minus the fasting oxygen consumption (VO2), was significantly greater for the normal than the obese men at submaximal intensities from O (unloaded cycling) to 100 W (p less than 0.05). The mean slope of the regressions of VO2 (ml . min-1) on power output (W), which reflects the rate of increase in energy expended relative to increases in external work performed, did not differ significantly between the fed and fasting conditions for either group, but the mean (+/- SEM) intercept was significantly higher for the normal, but not the obese men, in the fed than the fasting state (599 +/- 53 versus 497 +/- 47 ml O2 . min-1 for the normal men and 819 +/- 126 versus 821 +/- 145 ml O2 . min-1 for the obese men). These results indicate that the thermic effect of food during exercise, which is virtually absent in the obese men, does not increase significantly across submaximal power outputs for the normal men and therefore does not reflect a significant reduction in efficiency.
The recent literature suggests that high-protein, low-fat diets promote a greater degree of weight loss compared to high-carbohydrate, low-fat diets, but the mechanism of this enhanced weight loss is unclear. This study compared the acute, energy-cost of meal-induced thermogenesis on a high-protein, low-fat diet versus a high-carbohydrate, low-fat diet.
Ten healthy, normal weight, non-smoking female volunteers aged 19-22 years were recruited from a campus population. Using a randomized, cross-over design, subjects consumed the high-protein and the high-carbohydrate diets for one day each, and testing was separated by a 28- or 56-day interval. Control diets were consumed for two days prior to each test day. On test day, the resting energy expenditure, the non-protein respiratory quotient and body temperature were measured following a 10-hour fast and at 2.5-hour post breakfast, lunch and dinner. Fasting blood samples were collected test day and the next morning, and complete 24-hour urine samples were collected the day of testing.
Postprandial thermogenesis at 2.5 hours post-meal averaged about twofold higher on the high protein diet versus the high carbohydrate diet, and differences were significant after the breakfast and the dinner meals (p < 0.05). Body temperature was slightly higher on the high protein diet (p = 0.08 after the dinner meal). Changes in the respiratory quotient post-meals did not differ by diet, and there was no difference in 24-hour glomerular filtration rates by diet. Nitrogen balance was significantly greater on the high-protein diet compared to the high-carbohydrate diet (7.6 +/- 0.9 and -0.4 +/- 0.5 gN/day, p < 0.05), and at 24-hour post-intervention, fasting plasma urea nitrogen concentrations were raised on the high protein diet versus the high-carbohydrate diet (13.9 +/- 0.9 and 11.2 +/- 1.0 mg/dL respectively, p < 0.05).
These data indicate an added energy-cost associated with high-protein, low-fat diets and may help explain the efficacy of such diets for weight loss.
The aim of this review was to evaluate data regarding potential thermodynamic mechanisms for increased rates of weight loss in subjects consuming diets high in protein and/or low in carbohydrate. Studies that compared weight loss and energy expenditure in adults consuming diets high in protein and/or low in carbohydrate with those in adults consuming diets low in fat were reviewed. In addition, studies that measured the metabolizable energy of proteins, fats, and carbohydrates were reviewed. Diets high in protein and/or low in carbohydrate produced an approximately equal to 2.5-kg greater weight loss after 12 wk of treatment. Neither macronutrient-specific differences in the availability of dietary energy nor changes in energy expenditure could explain these differences in weight loss. Thermodynamics dictate that a calorie is a calorie regardless of the macronutrient composition of the diet. Further research on differences in the composition of weight loss and on the influence of satiety on compliance with energy-restricted diets is needed to explain the observed increase in weight loss with diets high in protein and/or low in carbohydrate.
For years, proponents of some fad diets have claimed that higher amounts of protein facilitate weight loss. Only in recent years have studies begun to examine the effects of high protein diets on energy expenditure, subsequent energy intake and weight loss as compared to lower protein diets. In this study, we conducted a systematic review of randomized investigations on the effects of high protein diets on dietary thermogenesis, satiety, body weight and fat loss. There is convincing evidence that a higher protein intake increases thermogenesis and satiety compared to diets of lower protein content. The weight of evidence also suggests that high protein meals lead to a reduced subsequent energy intake. Some evidence suggests that diets higher in protein result in an increased weight loss and fat loss as compared to diets lower in protein, but findings have not been consistent. In dietary practice, it may be beneficial to partially replace refined carbohydrate with protein sources that are low in saturated fat. Although recent evidence supports potential benefit, rigorous longer-term studies are needed to investigate the effects of high protein diets on weight loss and weight maintenance.
The thermic effect of food (TEF) is an important physiological determinant of total daily energy expenditure (EE) and energy balance. TEF is believed to be mediated in part by sympathetic nervous system activation and consequent beta-adrenergic receptor (beta-AR) stimulation of metabolism. TEF is greater in habitually exercising than in sedentary adults, despite similar postprandial sympathetic nervous system activation. We determined whether augmented TEF in habitually exercising adults is associated with enhanced peripheral thermogenic responsiveness to beta-AR stimulation. In separate experiments in 22 sedentary and 29 habitually exercising adults, we measured the increase in EE (indirect calorimetry, ventilated hood) during beta-AR stimulation (intravenous isoproterenol: 6, 12, and 24 ng x kg fat-free mass(-1) x min(-1)) and EE before and after a liquid meal (40% of resting EE; 53% carbohydrate, 32% fat, 15% protein). The increase in EE during incremental isoproterenol administration was greater (P = 0.01) in habitual exercisers (0.34 +/- 0.03, 0.54 +/- 0.04, 0.81 +/- 0.05 kJ/min; means +/- SE) than in sedentary adults (0.26 +/- 0.03, 0.40 +/- 0.03, 0.64 +/- 0.04 kJ/min). The area under the TEF response curve was also greater (P = 0.04) in habitual exercisers (160 +/- 9 kJ) than in sedentary adults (130 +/- 11 kJ) and was positively related to beta-AR thermogenic responsiveness (r = 0.32, P = 0.02). We conclude that TEF is related to beta-AR thermogenic responsiveness and that the greater TEF in habitual exercisers is attributable in part to their augmented beta-AR thermogenic responsiveness. Our results also suggest that peripheral thermogenic responsiveness to beta-AR stimulation is a physiological determinant of TEF and hence energy balance in healthy adult humans.
ACSM's guidelines for exercise testing and prescription
- Wr Thompson
Thompson WR. ACSM's guidelines for exercise testing and prescription, 8th ed. Philadelphia, PA, Lippincott Williams & Wilkins, 2010.