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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic Rate: A Randomized Trial

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The purpose of this study was to determine the effects of resistance training only (RT n=10), dietary intervention only (DIET n=10), resistance training plus diet (RT+DIET n=10) and control (CON n=10) on body composition and resting metabolic rate (RMR) in a cohort of 40 premenopausal female volunteers. Subjects in DIET and RT+DIET were provided with daily macronutrient and calorie goals based on DXA and RMR tests, with protein maintained at 1.4 g/kg/day. Subjects in the RT and RT+DIET groups performed a supervised progressive RT program consisting of exercises for all the major muscle groups of the body. Results showed a significant month-by-group interaction for change in fat mass with no significant linear trend for control. The three treatment groups all showed significant linear decreases in fat mass, but the slope of the decrease became progressively steeper from the RT, to DIET, to RT+DIET. A significant linear increase for lean mass was seen for resistance training-only. There was a non-significant increase in RMR in all groups from Month 0 to Month 4 but no significant month by group interaction. In conclusion, significant reductions in fat mass were achieved by all experimental groups, but results were maximized by RT+DIET. Only the RT group showed significant increases in lean mass.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Note: This article will be published in a forthcoming issue of the
International Journal of Sport Nutrition and Exercise
Metabolism. This article appears here in its accepted, peer-
reviewed form; it has not been copyedited, proofed, or formatted
by the publisher.
Section: Original Research
Article Title: Resistance Training Combined With Diet Decreases Body Fat While Preserving
Lean Mass Independent of Resting Metabolic Rate: A Randomized Trial
Authors: Todd Miller1, Stephanie Mull1, Alan Albert Aragon2, James Krieger3, and Brad Jon
Schoenfeld4
Affiliations: 1George Washington University, Milken School of Public Health, Washington,
D.C. 2California State University, Northridge, CA. 3Weightology, LLC, Issaquah, WA. 4CUNY
Lehman College, Department of Health Sciences, Bronx, NY.
Running Head: Resistance training effects on fat loss
Journal: International Journal of Sport Nutrition and Exercise
Acceptance Date: August 17, 2017
©2017 Human Kinetics, Inc.
DOI: https://doi.org/10.1123/ijsnem.2017-0221
Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
RUNNING TITLE: Resistance training effects on fat loss
Resistance training combined with diet decreases body fat while preserving lean
mass independent of resting metabolic rate: A randomized trial
Todd Miller1
Stephanie Mull1
Alan Albert Aragon2
James Krieger3
Brad Jon Schoenfeld4
1George Washington University, Milken School of Public Health, Washington, D.C.
2California State University, Northridge, CA
3Weightology, LLC, Issaquah, WA, USA
4CUNY Lehman College, Department of Health Sciences, Bronx, NY
WORD COUNT: 2968
Funding: The study was funded by a grant from the Sumner M. Redstone Global Center for
Prevention and Wellness. The authors declare no conflicts of interest.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Abstract
The purpose of this study was to determine the effects of resistance training only (RT n=10),
dietary intervention only (DIET n=10), resistance training plus diet (RT+DIET n=10) and control
(CON n=10) on body composition and resting metabolic rate (RMR) in a cohort of 40
premenopausal female volunteers. Subjects in DIET and RT+DIET were provided with daily
macronutrient and calorie goals based on DXA and RMR tests, with protein maintained at 1.4
g/kg/day. Subjects in the RT and RT+DIET groups performed a supervised progressive RT
program consisting of exercises for all the major muscle groups of the body. Results showed a
significant month-by-group interaction for change in fat mass with no significant linear trend for
control. The three treatment groups all showed significant linear decreases in fat mass, but the
slope of the decrease became progressively steeper from the RT, to DIET, to RT+DIET. A
significant linear increase for lean mass was seen for resistance training-only. There was a non-
significant increase in RMR in all groups from Month 0 to Month 4 but no significant month by
group interaction. In conclusion, significant reductions in fat mass were achieved by all experimental
groups, but results were maximized by RT+DIET. Only the RT group showed significant increases in lean
mass.
Keywords: Body composition, strength training, fat-free mass
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Introduction
Aerobic exercise (AE) is commonly recommended as the most effective exercise modality
for weight loss (Haskell et al., 2007). The American College of Sports Medicine (ACSM) position
stand on physical activity for weight loss recommends 150-250 minutes per week of moderate
intensity physical activity (Donnelly et al., 2009). While the ACSM promotes resistance training
(RT) as a means of increasing fat free mass, which should lead to improved body composition, it
does not promote RT for losing significant amounts of body fat. Similarly, the United States Public
Health Service physical activity guidelines for weight loss do not mention RT at all as a viable
exercise modality for weight loss. This is not surprising, as there is a paucity of research examining
the effects of RT on weight loss. Furthermore, the few studies that have explored RT for weight
loss generally show that it is ineffective (Olson, Dengel, Leon, & Schmitz, 2007; Willis et al.,
2012). Indeed, the effectiveness of any weight loss program is dependent on the size of the caloric
deficit that is created over time, and since AE generally burns more calories per unit of time than
RT (Donnelly et al., 2009), it stands to reason that AE would be the most commonly prescribed
type of exercise for losing weight. Contributing to the exclusion of RT for weight loss is a
widespread belief among dietitians, nutritionists and exercise professionals that it is not possible
to induce hypertrophy while in a caloric deficit, and since the creation of a caloric deficit is
essential for fat loss, the use of RT for muscle growth in a caloric deficit is counter-intuitive. These
beliefs continue to exist despite emerging evidence to the contrary (Josse, Atkinson, Tarnopolsky,
& Phillips, 2011; Longland, Oikawa, Mitchell, Devries, & Phillips, 2016).
RT has been shown to elevate resting metabolism for an extended period of time following
cessation of the training session (Stiegler & Cunliffe, 2006). Additionally, having a greater muscle
mass should lead to a greater resting metabolism (Gallagher et al., 1998). Unlike RT, chronic AE
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
performed in a caloric deficit (which is often the recommendation for effective weight loss) has
the potential to lead to significant decreases in muscle mass, thereby hampering improvements in
body composition (Swift, Johannsen, Lavie, Earnest, & Church, 2014). Ideally, a program
designed to improve body composition should do so through the loss of fat alone, with muscle
mass being maintained or increased. This is particularly important to premenopausal females, as
it has been reported that major weight gain occurs in women at a rate twice that of men, and is
highest in persons aged 25-34 (Williamson, Kahn, Remington, & Anda, 1990). Moreover, women
have lower baseline levels of muscle mass compared to men, and thus are at greater risk of negative
complications when muscle proteins are lost during dieting.
Several reasons could exist for the lack of effectiveness of RT reported in most weight loss
studies (Donnelly et al., 2009). Possible explanations include, but are not limited to, 1) a lack of
control and/or measurement of caloric intake; 2) failure to adjust dietary protein needs to support
muscle growth; and 3) an inadequate RT stimulus. Case studies of clients from our laboratory have
routinely demonstrated that substantial decreases in body fat can be induced with RT as the
exclusive form of exercise. Furthermore, these decreases in body fat occur with concomitant
increases in muscle mass, while in a caloric deficit.
The purpose of this study was threefold: 1) To determine whether RT combined with
dietary intervention (RT+DIET) results in greater improvements in body composition compared
with RT or DIET alone in overweight/obese premenopausal women; 2) To determine whether RT
combined with dietary intervention (RT+DIET) results in greater improvements in fat mass in the
visceral depot compared with RT or DIET alone, and; 3) To determine whether concomitant
increases in muscle mass and decreases in fat mass can occur while in a caloric deficit.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Methods
Subjects
Subjects were a convenience sample of 40 female volunteers (Body mass = 87.4±12.6;
Height = 165.7±7; Age = 32.3±4.8; BMI = 31.9±4.4). The sample size was based on previous
research by Jabekk (Jabekk, Moe, Meen, Tomten, & Hostmark, 2010) using change in fat mass as
the outcome measure with a target effect size difference of 0.4, alpha of 0.05 and minimum power
of 0.80. Recruitment took place from 4/1/16 to 5/14/16, and follow up took place from 8/15/16 to
9/16/16. The following inclusion criteria had to be met for participation: 1) women between 25-40
years of age; 2) regular menstrual cycle; 3) body fat >30%; 4) normally active; 5) not currently
meeting CDC physical activity guidelines; 6) no organized weight training within past 1 year; 7)
not currently dieting or food logging. Exclusion criteria included: 1) Subjects who do not have the
ability to exercise based on a Physical Activity Readiness questionnaire; 2) history of an eating
disorder; injury or medical issue that would prohibit them from resistance training; 3) pregnant or
nursing. Following recruitment, subjects were given a screening questionnaire either in-person,
electronically (via email), or verbally (via phone), in order to determine whether they were viable
candidates. Informed consent was obtained at the time of screening. The study was conducted
according to the Declaration of Helsinki, and was approved by the local University Ethics
Committee.
Random sequences were generated by the PI using a random number generator app
from https://www.random.org/. A 40 number sequence was randomly produced by the app.
Subjects were then asked by the PI to press the button on the app, and were randomly assigned to
one of 4 groups based on the following result from the app: 0-10 = Control (CON n=10); 11-20=
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Dietary intervention only (DIET n=10); 21-30 = Resistance Training only (RT n=10); 31-40 =
Resistance Training plus Diet (RT+DIET n=10).
Testing:
Subjects meeting criteria as defined by the screening survey reported to the University lab
for secondary screening at 9:00 a.m. following an overnight fast. Body composition was then
measured via Dual Energy X-ray Absorptiometry (iDXA, Lunar; GE Medical Systems, Madison,
WI, USA). All DXA scans were analyzed using enCORE 2012 software, version 14.1 to determine
total percentage of fat and lean tissue, bone mineral content and visceral adipose tissue. Subjects
were instructed to report to the lab after an overnight fast having refrained from exercise for 48
hours and to remain normally hydrated prior to body composition and RMR assessment.
After DXA scanning, subjects underwent testing for resting metabolic rate (RMR) via
indirect calorimetry to determine daily resting caloric expenditure. Subjects sat quietly in a
reclined position and breathed normally for 10-12 minutes through a one-way valve with the nose
plugged. The subject inhaled normal room air, and exhaled air was continuously collected and sent
to a KorrReeVue indirect calorimeter (Korr Medical Technologies, Salt Lake City, UT USA).
RMR was calculated by the calorimeter (Korr ReeVue, Salt Lake City, UT), which automatically
begins collecting gas when it detects the first breath into the machine and then stops automatically
once the collection time is complete.
Follow-up DXA scans were obtained at weeks 4, 8, 12 and 16 and RMR testing was
repeated at week 16.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Diet
Subjects in DIET and RT+DIET groups met individually with a registered dietitian and
were given daily macronutrient and calorie goals based on their DXA and RMR tests. Calculation
of daily caloric intake was based on the Harris-Benedict equation as follows with the objective of
energy-restriction: If the RMR was within 10% of the predicted RMR, intake was set at the RMR;
if the RMR was greater than 10% over the predicted, intake was set at 10% below the measured
RMR; if the RMR was greater than 10% below the predicted, intake was set at 10% above the
measured RMR. Fat intake was set at 20% of total calories. Protein intake was calculated using a
factor of 3.1 g of protein per kg of fat free mass (Helms, Zinn, Rowlands, & Brown, 2014).
Carbohydrate made up the balance of the remaining calories.
Subjects in the DIET and RT+DIET groups began following the prescribed caloric and
macronutrient goals as established in their meeting with the dietitian within one week of the initial
meeting and continued this regimen over the entire course of the study. To track nutritional
consumption, subjects were familiarized with the usage of a phone app & website for food logging
(fatsecret.com). During the course of the study, subjects logged all of their foods daily into the
fatsecret app and the data were then analyzed to determine total energy and macronutrient intake.
Exercise
Within two weeks following initial screening, subjects in the RT and RT+DIET groups
reported to Power Train Sports and Fitness (www.powertrainsports.com) for an exercise
familiarization session. Subjects met with a certified trainer from Power Train who walked them
through the exercise program, taught proper exercise form, and establish appropriate training
loads.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
The RT intervention began within one week following the exercise familiarization session.
All training sessions were performed under the individual supervision of a certified personal trainer
from Power Train. Training sessions continued at a rate of 2-3 per week (depending on training
phase) for 16 weeks.
The RT intervention consisted of two separate workout complexes that were alternated
every 4 weeks for the duration of the 16-week study. Exercise complex one consisted of Squats,
Romanian Deadlifts, Swiss Ball Squats, Bench Press, Lat Pulldown, Dumbbell Shoulder Press,
Incline Dumbbell Fly, Seated Row, Dumbbell Lateral Raise and Low Back Hyperextensions.
Exercise complex two consisted of Deadlifts, Leg Curls, Leg Extensions, Incline Dumbbell Press,
Close Grip Pulldowns, Arnold Press, Cable Crossover, Chest Supported Dumbbell Row, Face
Pulls and Low Back Hyperextension. Each exercise was completed for 4 sets of 10-12RM. Rest
periods between sets were between 60-90 seconds. Subjects trained 3 times per week for weeks 1-
3 of each month, then trained twice weekly during the 4th week of each month. Training loads for
a given exercise were increased when the subject could complete greater than 12 reps on the first
set, or when she could complete 12 reps on all 4 sets. Loads were progressively increased in order
to keep the RM in the 10-12 range.
Statistics
Data were modeled using a linear mixed model for repeated measures, estimated by a
restricted maximum likelihood algorithm, with drop-outs removed from the dataset. Diet
intervention (control, diet, resistance training, resistance training + diet) was included as the
between-subject factor, month (0, 1, 2, 3, 4) was included as the repeated within-subjects factor,
month x intervention was included as the interaction, and subject was included as a random effect.
In cases where significant interactions were present, linear time trends of within-group changes
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
were analyzed using linear mixed models for repeated measures. Comparisons of statistically
significant slopes for linear time trends were done using t-tests with a Holm-Bonferonni correction
for multiple comparisons.. Degrees of freedom were calculated using a Satterthwaite
approximation. Comparisons between self-reported dietary data were performed using
independent t-tests. All analyses were performed using package lmertest in R version 3.3.1 (The
R Foundation for Statistical Computing, Vienna, Austria). Effects were considered significant at
P ≤ 0.05. Data are reported as
x
± SD unless otherwise specified.
Results
A total of 31 subjects completed the study, with 9 dropouts (Control: n=8; RT: n=9; DIET:
n=9; RT+DIET: n=5). The reasons for the dropouts are as follows: 1 subject got deployed; 1
subject moved; 2 subjects suffered work-related injuries not connected to the study; and 5 subjects
ceased participation for unknown personal reasons. Outcomes for all variables are presented in
Table 1. One-way ANOVA was used to compare baseline characteristics between groups. There were no
significant differences in age (P = 0.73), body mass (P = 0.67), fat mass (P = 0.81), FFM (P = 0.63), BMC
(P = 1.0), or RMR (P = 0.83). Based on review of self-report dietary logs and estimates of energy
expenditure, diet-only achieved a daily energy restriction of ~502 kcal while training+diet achieved a daily
energy restriction of ~632 kcal.
Body Weight
There was a significant month by group interaction (P = 0.02). There was no significant
linear trend for control = 0.41; 95% CI = -1.08, 1.90; P = 0.58) or resistance-training-only groups
(β = 0.18; 95% CI = -0.36, 0.73; P = 0.51). There were similar significant linear decreases for the
diet-only (β = -1.35; 95% CI = -2.03, -0.67; P = 0.0004) and resistance training+diet groups (β = -
1.68; 95% CI = -2.51, -0.85; P = 0.0006). See Figure 1.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Percent Fat
There was a significant month by group interaction (P = 0.004). There was no significant
linear trend for control (β = 0.07; 95% CI = -0.12, 0.26; P = 0.45). There were similar significant
linear decreases for the diet-only (β = -0.40; 95% CI = -0.54, -0.26; P = 0.0), resistance-training
only = -0.38; 95% CI = -0.57, -0.19; P = 0.0003), and resistance-training+diet groups = -
0.53; CI = -0.74, -0.33; P < 0.0001). See Figure 2.
Fat Mass
There was a significant month by group interaction (P = 0.003). There was no significant
linear trend for control (β = 0.38; 95% CI = -0.62, 1.37; P = 0.46). The three treatment groups all
showed significant linear decreases in fat mass, but the slope of the decrease became progressively
steeper from the resistance-training only group, to the diet-only group, to the resistance-
training+diet group (resistance training-only: β = -0.58; 95% CI = -1.02, -0.14; P = 0.01; diet-
only: β = -1.35; 95% CI = -1.87, -0.83; P = 0.0; resistance training+diet: β = -1.80; 95% CI = -
2.43, -1.17; P < 0.0001). See Figure 3. When comparing the three statistically significant slopes
for fat mass using t-tests corrected for multiple comparisons by Holm-Bonferroni, resistance
training+diet showed a significantly greater slope than resistance training-only (P = 0.0019 tested
at 0.017 Holm-Bonferonni threshold); diet-only showed a non-significantly greater slope than
resistance training-only (P = 0.027 tested at 0.025 Holm-Bonferonni threshold). There was no
significant difference between resistance training+diet and diet-only (P = 0.29).
Lean Mass
There was nearly a significant month by group interaction (P = 0.052). There was no
significant linear trend for control (β = 0.03; 95% CI = -0.52, 0.57; P = 0.93), diet-only (β = -0.004;
CI = -0.30, 0.29; P = 0.98), or resistance training+diet (β = 0.11; 95% CI = -0.40, 0.62; P = 0.67).
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
There was a significant linear increase for resistance training-only (β = 0.76; 95% CI = 0.32, 1.2;
P = 0.002). See Figure 4.
Bone Mineral Content
There was no significant month by group interaction (P = 0.077). There were no significant
linear trends for any groups (Control: β = -0.003; 95% CI = -0.01, 0.01; P = 0.60; Diet-Only: β =
-0.01; 95% CI = -0.03, 0.004; P = 0.16; Resistance Training-Only: β = 0.009; 95% CI = -0.004,
0.02; P = 0.17; Resistance Training+Diet: β = 0.008; 95% CI = -0.01, 0.03; P = 0.46).
VAT
There was no significant month by group interaction (P = 0.20), group effect (P = 0.86), or
month effect (P = 0.14) for VAT.
Resting Metabolic Rate (RMR)
There was no significant month by group interaction (P = 0.79) or group effect (P = 0.76).
There was a non-significant (P = 0.092) increase in RMR in all groups from Month 0 to Month 4.
There were no significant interactions or main effects for RMR as a percentage of the predicted
value, with p-values ranging from 0.28 0.58 (pertaining to both the interaction term in the model, and
the two main effects)
Self-Reported Dietary Data
Self-reported dietary data are shown in Table 2. There were no significant differences
between the diet-only and diet+training groups for self-reported calorie intake (P = 0.49),
carbohydrate intake (P = 0.31), fat intake (P = 0.71), or protein intake (P = 0.62). There were also
no significant differences between groups for percentage of goals for calorie intake or
macronutrients (P = 0.23 0.75).
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Group dietary time trends are shown in Table 2. There was no significant month by group
interaction for calories (P = 0.40), protein (P = 0.77), or carbohydrate (P = 0.44). There were no
main effects of group for calories (P = 0.45), protein (P = 0.44), or carbohydrate (P = 0.31), nor
were there main effects of time for calories (P = 0.23), protein (P = 0.09), or carbohydrate (P =
0.41). There was a significant month by group interaction for fat (P = 0.02). There was a significant
linear trend for fat to decrease in the diet only group = -1.20; CI = -2.30, -0.10; P = 0.04),
whereas there was no trend in the diet and training group (P = 0.51).
Discussion
The study produced several notable findings. First, while reductions in fat mass were
achieved by all experimental groups, results were maximized by combining of RT and diet.
Second, only the RT group showed significant increases in lean mass; combining RT with diet
attenuated these increases. Finally, RMR remained unchanged over the course of the study period
for all conditions; changes in lean mass did not significantly affect this outcome.
The well-established negative effects of excess body fat on health and wellness underscore
the importance of determining effective strategies for weight loss. All treatments produced
significant reductions in fat mass over the 16 week study period, with the exception of RT-only,
which showed a decrease in fat mass at months 1-3, but an increase in fat mass at month 4. These
losses persisted in a linear fashion across each month of the study, with the slope of the decrease
becoming progressively steeper from RT-only to DIET-only to RT+DIET. Although RT-only did
not receive any nutritional prescription and were told not to make any modifications to their usual
diet, this group apparently was in a hypocaloric state during the initial 3 months of the trial, perhaps
inspired by a desire to realize additional benefits upon initiating an exercise program. The increase
in fat mass at the fourth month may have reflected a lapse in eating restraint due to an absence of
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
dietary programming. These results reinforce the fact that nutritional intervention combined with
exercise is paramount with respect to fat loss, with exercise providing a supplemental but important
role in the process. Illustrating this point, a systematic review and meta-analysis by Clark (Clark,
2015) found that diet plus RT or a combination of RT and AE had a greater impact on improving
body composition than diet alone. In a study specific to resistance training, Bouchard et al
(Bouchard, Soucy, Senechal, Dionne, & Brochu, 2009) compared the effects of caloric restriction
(CR), resistance training (RT), or a combination of the two (CR + RT) in a cohort of obese
postmenopausal women. Significant fat loss occurred in CR and CR + RT, but not RT alone.
The maintenance of high levels of muscle mass has implications on physical function, and
plays a role in the prevention of common pathologic conditions and chronic diseases (Wolfe,
2006). In this regard, only the RT group showed a significant increase in lean mass, with subjects
gaining 2.2 kg over the 16 week study period. In the absence of caloric restriction, lean mass gains
via resistance training are expected, especially in untrained subjects. In an investigation with a
similar subject profile (obese women age 20-40 yrs in nondieting conditions), Jabekk et al (Jabekk
et al., 2010) reported that the nondieting control group gained 1.5 kg FFM during 10 weeks of RT.
Assuming the same rate of gain extended another 6 weeks to match the length of the present study,
this would have amounted to 2.4 kg FFM; which is consistent with the gain of 2.2 kg seen in the
present study. In contrast with recent studies (Josse et al., 2011; Longland et al., 2016), the
RT+DIET group did not show significant increases in lean mass over the duration of the study.
However, it should be noted that there was a linear increase over the first 12 weeks of the study,
with an apparent loss of these gains during the final month. The reason for this finding is not
readily apparent. An additional consideration is that water is the predominant and most widely
fluctuating component of FFM due to varying glycogen concentrations, electrolyte balance
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
influencing hydration, and other factors. Therefore, increases in FFM are not necessarily
accompanied by directly proportional increases in contractile protein and do not necessarily reflect
gains in muscle mass.
Interestingly, the diet-only group did not lose any FFM over the 16 week intervention
period. Research generally shows a loss of lean tissue concomitant to a caloric deficit. It is
conceivable that the high-protein content of the diet (3.1 g/kg/FFM) helped to offset any such
losses. In support of this, a systematic review by Helms et al (Helms et al., 2014) reported that
lean, resistance-trained subjects in hypocaloric conditions required a protein intake of 2.3-3.1 g/kg
FFM in order to maximally protect against lean tissue losses. In addition, the present study did not
involve particularly aggressive caloric restriction (1419 & 1505 kcal/day in DIET and RT + DIET,
respectively). Despite rigorous efforts to ensure compliance to the diet (i.e. weekly review of food
logs, ongoing email support for dietary tracking, and monthly meetings with the dietician to answer
any diet-related questions), there nevertheless is the possibility of under-reporting of caloric intake.
Lichtman et al (Lichtman et al., 1992) found that obese subjects under-reported their intake by an
average of 47% (a group mean of 1053 kcal/day). Thus, in addition to the non-aggressively
prescribed caloric deficit, the potential for under-reporting total energy combined with the high
protein intake target could have spared FFM.
There were no significant changes in RMR noted from pre- to post-study in any of the
conditions studied. Our results on the topic concur with the body of literature, which shows that
changes in lean mass do not necessarily parallel changes in RMR (Stiegler & Cunliffe, 2006).
Although there is a clear metabolic cost of maintaining lean mass, the actual energy expenditure
associated with skeletal muscle is rather low, estimated at only ~13 kcal/kg per day (Wang et al.,
2011). Aristizabal et al. (Aristizabal et al., 2015) recently investigated the possibility of estimating
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
RMR responses in resistance-training subjects via DXA-measured changes in FFM. Although
there was a large degree of interindividual variability, 9 months of resistance training and
supplementation with either protein or carbohydrate increased RMR by an average of 5%, and
FFM (among other factors) was positively correlated with this small but significant increase. In
light of this finding, it is possible that the present study would need a longer duration to detect
significant changes in RMR.
Our study had several notable limitations that must be considered when making evidence-
based inferences from the data. First, although DXA is a well-established modality for estimating
body composition, the measurement of lean mass is specific to all non-fat and bone-free
components, and thus does not necessarily reflect changes in skeletal muscle. Second, given that
the subjects were premenopausal women, menstrual changes may have altered observed changes
in body composition. Third, the findings are specific to obese, premenopausal women and cannot
necessarily be generalized to other populations. Finally, the sample size was rather small, thereby
limiting statistical power for probability assessment.
Conclusion
Findings of this study indicate that a total-body RT program combined with a caloric deficit
is a viable strategy for reducing body fat while preserving lean mass in obese, premenopausal
women. Positive results do not appear to be related to increases in RMR. Given the health-related
implications for carrying excess body fat, these findings indicate that diet is the paramount
consideration for combating obesity and combining nutritional prescription with RT appears to
help optimize changes in body composition.
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
References
Aristizabal, J. C., Freidenreich, D. J., Volk, B. M., Kupchak, B. R., Saenz, C., Maresh, C. M., . . .
Volek, J. S. (2015). Effect of resistance training on resting metabolic rate and its
estimation by a dual-energy X-ray absorptiometry metabolic map. European Journal of
Clinical Nutrition, 69(7), 831-836. doi:10.1038/ejcn.2014.216 [doi]
Bouchard, D. R., Soucy, L., Senechal, M., Dionne, I. J., & Brochu, M. (2009). Impact of
resistance training with or without caloric restriction on physical capacity in obese older
women. Menopause (New York, N.Y.), 16(1), 66-72. doi:10.1097/gme.0b013e31817dacf7
[doi]
Clark, J. E. (2015). Diet, exercise or diet with exercise: Comparing the effectiveness of treatment
options for weight-loss and changes in fitness for adults (18-65 years old) who are
overfat, or obese; systematic review and meta-analysis. Journal of Diabetes and
Metabolic Disorders, 14, 31-015-0154-1. eCollection 2015. doi:10.1186/s40200-015-
0154-1 [doi]
Donnelly, J. E., Blair, S. N., Jakicic, J. M., Manore, M. M., Rankin, J. W., Smith, B. K., &
American College of Sports Medicine. (2009). American college of sports medicine
position stand. appropriate physical activity intervention strategies for weight loss and
prevention of weight regain for adults. Medicine and Science in Sports and Exercise,
41(2), 459-471. doi:10.1249/MSS.0b013e3181949333;
10.1249/MSS.0b013e3181949333
Gallagher, D., Belmonte, D., Deurenberg, P., Wang, Z., Krasnow, N., Pi-Sunyer, F. X., &
Heymsfield, S. B. (1998). Organ-tissue mass measurement allows modeling of REE and
metabolically active tissue mass. The American Journal of Physiology, 275(2 Pt 1),
E249-58.
Haskell, W. L., Lee, I. M., Pate, R. R., Powell, K. E., Blair, S. N., Franklin, B. A., . . . American
Heart Association. (2007). Physical activity and public health: Updated recommendation
for adults from the american college of sports medicine and the american heart
association. Circulation, 116(9), 1081-1093. doi:CIRCULATIONAHA.107.185649 [pii]
Helms, E. R., Zinn, C., Rowlands, D. S., & Brown, S. R. (2014). A systematic review of dietary
protein during caloric restriction in resistance trained lean athletes: A case for higher
intakes. International Journal of Sport Nutrition and Exercise Metabolism, 24(2), 127-
138. doi:10.1123/ijsnem.2013-0054 [doi]
Jabekk, P. T., Moe, I. A., Meen, H. D., Tomten, S. E., & Hostmark, A. T. (2010). Resistance
training in overweight women on a ketogenic diet conserved lean body mass while
reducing body fat. Nutrition & Metabolism, 7, 17-7075-7-17. doi:10.1186/1743-7075-7-
17 [doi]
Downloaded by Griffith University Library on 09/06/17, Volume 0, Article Number 0
Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Josse, A. R., Atkinson, S. A., Tarnopolsky, M. A., & Phillips, S. M. (2011). Increased
consumption of dairy foods and protein during diet- and exercise-induced weight loss
promotes fat mass loss and lean mass gain in overweight and obese premenopausal
women. The Journal of Nutrition, 141(9), 1626-1634. doi:10.3945/jn.111.141028 [doi]
Lichtman, S. W., Pisarska, K., Berman, E. R., Pestone, M., Dowling, H., Offenbacher, E., . . .
Heymsfield, S. B. (1992). Discrepancy between self-reported and actual caloric intake
and exercise in obese subjects. The New England Journal of Medicine, 327(27), 1893-
1898. doi:10.1056/NEJM199212313272701 [doi]
Longland, T. M., Oikawa, S. Y., Mitchell, C. J., Devries, M. C., & Phillips, S. M. (2016). Higher
compared with lower dietary protein during an energy deficit combined with intense
exercise promotes greater lean mass gain and fat mass loss: A randomized trial. The
American Journal of Clinical Nutrition, 103(3), 738-746. doi:10.3945/ajcn.115.119339
[doi]
Olson, T. P., Dengel, D. R., Leon, A. S., & Schmitz, K. H. (2007). Changes in inflammatory
biomarkers following one-year of moderate resistance training in overweight women.
International Journal of Obesity (2005), 31(6), 996-1003. doi:0803534 [pii]
Stiegler, P., & Cunliffe, A. (2006). The role of diet and exercise for the maintenance of fat-free
mass and resting metabolic rate during weight loss. Sports Medicine (Auckland, N.Z.),
36(3), 239-262. doi:3635 [pii]
Swift, D. L., Johannsen, N. M., Lavie, C. J., Earnest, C. P., & Church, T. S. (2014). The role of
exercise and physical activity in weight loss and maintenance. Progress in
Cardiovascular Diseases, 56(4), 441-447. doi:10.1016/j.pcad.2013.09.012 [doi]
Wang, Z., Ying, Z., Bosy-Westphal, A., Zhang, J., Heller, M., Later, W., . . . Muller, M. J.
(2011). Evaluation of specific metabolic rates of major organs and tissues: Comparison
between men and women. American Journal of Human Biology : The Official Journal of
the Human Biology Council, 23(3), 333-338. doi:10.1002/ajhb.21137 [doi]
Williamson, D. F., Kahn, H. S., Remington, P. L., & Anda, R. F. (1990). The 10-year incidence
of overweight and major weight gain in US adults. Archives of Internal Medicine, 150(3),
665-672.
Willis, L. H., Slentz, C. A., Bateman, L. A., Shields, A. T., Piner, L. W., Bales, C. W., . . . Kraus,
W. E. (2012). Effects of aerobic and/or resistance training on body mass and fat mass in
overweight or obese adults. Journal of Applied Physiology (Bethesda, Md.: 1985),
113(12), 1831-1837. doi:10.1152/japplphysiol.01370.2011 [doi]
Wolfe, R. R. (2006). The underappreciated role of muscle in health and disease. The American
Journal of Clinical Nutrition, 84(3), 475-482. doi:84/3/475 [pii]
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Figure 1. Effect of experimental conditions on changes in body weight in Diet Only, Resistance
Training Only, and Resistance Training + Diet groups for each month across the duration of the
study. * denotes significant linear trend
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Figure 2. Effect of experimental conditions on changes in percent body fat in Diet Only,
Resistance Training Only, and Resistance Training + Diet groups for each month across the
duration of the study. * denotes significant linear trend
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Figure 3. Effect of experimental conditions on changes in fat mass in Diet Only, Resistance
Training Only, and Resistance Training + Diet groups for each month across the duration of the
study. * denotes significant linear trend
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
Figure 4. Effect of experimental conditions on changes in lean mass in Diet Only, Resistance
Training Only, and Resistance Training + Diet groups for each month across the duration of the
study. * denotes significant linear trend
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
TABLE 1: Outcomes for all variables across time (mean ± SD)
Outcome
Group
Month 0
Month 2
Month 4
Body Weight
(kgs)*
Control
86.0 ± 15.2
86.8 ± 18.0
Diet**
82.0 ± 11.3
80.3 ± 10.3
79.7 ± 10.2
Training
85.9 ± 15.3
86.1 ± 15.3
88.3 ± 16.0
Training +
Diet**
91.1 ± 4.4
89.5 ± 4.6
88.0 ± 4.0
Percent Fat*
Control
43.0 ± 6.0
43.3 ± 6.5
Diet**
44.0 ± 4.4
42.9 ± 4.2
42.2 ± 4.0
Training**
44.3 ± 6.0
42.9 ± 5.7
43.1 ± 6.6
Training +
Diet**
45.3 ± 4.7
43.8 ± 4.6
43.3 ± 4.5
Fat Mass
(kgs)*
Control
37.5 ± 10.5
38.1 ± 12.1
Diet**
36.4 ± 7.9
34.7 ± 7.0
33.9 ± 6.8
Training
38.6 ± 11.0
37.4 ± 10.5
38.6 ± 11.7
Training +
Diet**
41.3 ± 5.1
39.2 ± 5.1
38.0 ± 4.4
Lean Mass
(kgs)
Control
45.9 ± 6.9
46.0 ± 8.0
Diet
43.0 ± 4.6
43.0 ± 4.7
43.1 ± 4.6
Training**
44.7 ± 6.4
46.0 ± 6.7
46.9 ± 6.5
Training +
Diet
47.1 ± 4.5
47.6 ± 4.4
47.1 ± 4.7
BMC (kgs)
Control
2.7 ± 0.3
2.7 ± 0.3
Diet
2.7 ± 0.4
2.7 ± 0.4
2.7 ± 0.5
Training
2.7 ± 0.5
2.7 ± 1.0
2.7 ± 0.5
Training +
Diet
5.9 ± 0.4
5.9 ± 0.4
5.9 ± 0.3
VAT (kgs)
Control
0.9 ± 0.4
1.0 ± 0.5
Diet
0.8 ± 0.5
0.7 ± 0.4
0.7 ± 0.4
Training
0.8 ± 0.5
0.8 ± 0.6
0.9 ± 0.6
Training +
Diet
0.9 ± 0.4
0.9 ± 0.4
0.8 ± 0.3
RMR (kcal/d)
Control
1494 ± 193
1624 ± 301
Diet
1484 ± 232
1563 ± 216
Training
1525 ± 174
1544 ± 190
Training +
Diet
1595 ± 334
1673 ± 175
* = significant group x month interaction (P < 0.05)
** = significant linear time trend within group (P < 0.05)
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Resistance Training Combined With Diet Decreases Body Fat While Preserving Lean Mass Independent of Resting Metabolic
Rate: A Randomized Trial” by Miller T et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2017 Human Kinetics, Inc.
TABLE 2: Self-Reported Dietary Intake of Energy and Macronutrients for Each Month of the
Study (mean ± SD)
Aggregate Dietary Data
Diet Only
Diet + Training
Kcal
1419 ± 183
1505 ± 223
Protein (g)
114 ± 21
120 ± 23
Carbohydrate (g)
145 ± 24
159 ± 22
Fat (g)
42 ± 5
41 ± 7
Dietary Data by Month
Month 1
Month 2
Month 3
Month 4
Kcal
Diet
1439 ± 104
1441 ± 179
1397 ± 294
1401 ± 186
Diet+Training
1467 ± 319
1574 ± 211
1533 ± 219
1448 ± 198
Protein (g)
Diet
108 ± 17
116 ± 20
110 ± 34
108 ± 23
Diet+Training
118 ± 27
130 ± 20
122 ± 27
112 ± 29
arbohydrate (g)
Diet
147 ± 18
147 ± 27
143 ± 32
143 ± 25
Diet+Training
154 ± 36
165 ± 23
164 ± 32
154 ± 25
Fat (g) *
Diet**
46 ± 5
42 ± 6
40 ± 8
42 ± 5
Diet+Training
39 ± 8
42 ± 8
42 ± 7
41 ± 6
* = significant group x month interaction (P < 0.05)
** = significant linear time trend within group (P < 0.05)
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... However, EE calculations for single exercises, and acute changes to metabolic rate are not necessarily indicative of longer-term reductions in fat loss and body composition changes -potentially due to other lifestyle factors and behavioural compensation resulting in ~55-64% less weight loss than expected 24 . Further, Miller, et al. 25 reported reductions in fat mass by both diet and diet +RT groups. However, lean mass increased following RT only, and these changes did not significantly affect resting EE. ...
... The smallest effect size of interest for change in fat mass was determined as 3.3% loss of baseline body weight as fat mass based upon recommendations from American College of Sports Medicine Position Stand regarding weight loss 35 and that a previous study using a similar RT and dietary intervention over a ~4-week period found similar results 25 . A linear mixed effect model was fit using the "lme4" package 36 and which was essentially a within participant extension of an analysis of covariance model with adjustment for baseline measures. ...
... This suggests that any previously identified difference in EE during-or post-resistance exercise resulting from heavier-or lighter-load training [22][23] , does not translate to differences in reduction of fat mass (kg) or body fat percentage over the course of longitudinal intervention. Within conditions, both HL and LL interventions showed similar reductions in fat mass (HL, m= -0.67kg; LL, m= -0.55kg), and body fat percentage (HL, m= -0.70%; LL, m= -0.62%) although neither reached our pre-determined bounds of smallest meaningful change (i.e., 3.3% loss of baseline weight as fat mass 25,35 ). As a 4-week intervention period the present findings for fat mass and body fat percentage reductions are smaller than that reported for the first month of previous research considering diet and resistance training (e.g., -1.4kg, and -1.1% 25 ). ...
Preprint
Full-text available
To date no studies have compared resistance training loading strategies combined with dietary intervention for fat loss. Thus, we performed a randomised crossover design comparing four weeks of heavier- (HL; ~80% 1RM) and lighter-load (LL; ~60% 1RM) resistance training, combined with calorie restriction and dietary guidance, including resistance trained participants (n=130; males=49, females=81). Both conditions performed low-volume, (single set of 9 exercises, 2x/week) effort matched (to momentary failure), but non-work-matched protocols. Testing was completed pre- and post-each intervention. Fat mass (kg) was the primary outcome, and a smallest effect size of interest (SESOI) was established at 3.3% loss of baseline bodyweight. Body fat percentage, lean mass, and strength (7-10RM) for chest press, leg press, and pull-down exercises were also measured. An 8-week washout period of traditional training with normal calorie interspersed each intervention. Both interventions showed small statistically equivalent (within the SESOI) reductions in fat mass (HL: -0.67 kg [95%CI -0.91 to 0.42]; LL: -0.55 kg [95%CI -0.80 to -0.31]) which were also equivalent between conditions (HL – LL: -0.113 kg [95%CI -0.437 kg to 0.212 kg]). Changes in body fat percentage and lean mass were also minimal. Strength increases were small, similar between conditions, and within a previously determined SESOI for the population included (10.1%). Fat loss reductions are not impacted by resistance training load; both HL and LL produce similar, yet small, changes to body composition over a 4-week intervention. However, the maintenance of both lean mass and strength highlights the value of resistance training during dietary intervention.
... However, they included studies in which caloric restriction was different between intervention and control groups [14,15]. They also failed to include several relevant randomized controlled trials (RCTs) [11,[16][17][18][19][20][21]; therefore, their results might be biased. ...
... The included investigations were published between 1997 and 2018. Eight eligible articles were published in the USA [6,11,17,21,[26][27][28][29], one in Canada [20], Egypt [10], Brazil [16], and three in Asian countries [9,18,19]. All studies used a parallel design and the intervention duration ranged from 12 to 36 weeks. ...
... Most studies were conducted on females, except 3 studies which included both genders [6,16,29], and the participants were aged 30-80 years. Eight trials were conducted among postmenopausal women [6,11,16,20,21,[27][28][29], 3 trials included premenopausal participants [9,10,17] and pre-and post-menopausal women [18,19,26]. Moreover, the health status of participants was as follows: healthy overweight and/or obese individuals [9, 10, 17-21, 26, 27], patients with T2DM [16], healthy and individuals with stable hyperlipidemia and hypertension [11,28], healthy and subjects with stable medication [6], and overweight/obese with cardiometabolic disease or metabolic syndrome [29]. ...
Article
The effects of exercise in conjunction with weight-loss diets on bone health are mixed. Our objective was to systematically review and meta-analyze controlled clinical trials in adults investigating the addition of exercise to a weight-loss diet compared with a calorie-matched weight-loss diet without exercise on bone measures. Online databases including PubMed/MEDLINE, EMBASE, ISI (Web of Science), Scopus, and Google Scholar were searched up to April 2021 with no restriction. A random effects model was used to calculate the overall estimates. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Fourteen eligible controlled clinical trials were included in the systematic review. The meta-analysis revealed that, compared to weight-loss diets alone, the addition of exercise did not improve total body bone mineral density (BMD) [weighted mean difference (WMD) = 0.002 g/cm2, P = 0.62, n = 8], lumbar BMD (WMD = 0.007 g/cm2, P = 0.44, n = 9), total hip BMD (WMD = 0.015 g/cm2, P = 0.14, n = 4) and total bone mineral content (BMC) (WMD = - 11.97 g, P = 0.29, n = 7). Subgroup analysis revealed that resistance exercise in conjunction with hypocaloric diets positively affects total BMD compared to an energy restrictive diet alone (WMD = 0.01 g/cm2, P = 0.003, n = 3). Overall, it appears that only resistance exercise beneficially affects total BMD during a calorie-restricted diet in adults. Further well-controlled and long-term clinical trials are still needed to confirm these results. PROSPERO registration number: CRD42020173434.
... Cabe destacar que Pinto et al. (2014) lograron mejorar la fuerza y pruebas de rendimiento funcional en adultos mayores sedentarios con sólo 6 semanas de entrena-miento de fuerza, 2 sesiones/semana. Además, el entrenamiento de fuerza ayuda a conservar la masa magra mientras se reduce la grasa corporal (Miller et al., 2018;Mora et al., 2020;Sardeli et al., 2018), por lo que se optimiza la composición corporal y la salud metabólica. ...
... Debido a que la impedancia bioeléctrica tiene cierto error de estimación por varios factores (Sergi et al., 2017), no se puede asegurar que se haya producido tal disminución de forma exacta. Por otro lado, se podría afirmar que se ha mantenido la masa magra durante la pérdida de grasa gracias al entrenamiento (Miller et al., 2018;Sardeli et al., 2018), así como una mejora de la calidad muscular . ...
Article
Full-text available
La sociedad está envejeciendo, y se estima que este segmento seguirá aumentando en los próximos años. Objetivo: Examinar los efectos que producen 5 semanas de entrenamiento en el rendimiento funcional, fuerza de agarre, perímetro de cintura, masa grasa y percepción de dolor general. Método: 28 sujetos (edad ≥ 55 años), sedentarios, participaron en un programa de entrenamiento de fuerza y entrenamiento aeróbico, de 5 semanas, 5 sesiones semanales de 50-60 minutos de duración. Resultados: Existen diferencias estadísticamente significativas entre los valores previos y posteriores al programa. La magnitud de estas diferencias puede considerarse grande en el Timed Up and Go Test (-27.3%, p=0.000, d=3.01), 30-Second Chair Stand Test (+42%, p=0.000, d=1.77) y percepción de dolor día (-54.7%, p=0.000, d=1.27) y noche (-58.2%, p=0.000, d=1.02). Conclusión: Tras la aplicación del programa de entrenamiento concurrente descrito, todas las variables analizadas han evolucionado favorablemente. Dichas variables están directamente relacionadas con la composición corporal, calidad de vida, reducción del dolor, así como mejora de fuerza para las actividades cotidianas de las personas mayores.
... While resistance exercise impact on RMR of adolescent female athletes with low EA has not been addressed, a protective effect of resistance exercise on RMR during caloric restriction has been described. Resistance training combined with diet decreased fat mass but preserved FFM and RMR in adult women [53] and middle-aged obese individuals [13] compared to diet only groups. Silva et al. [54] showed that competitive athletes could increase FFM while losing fat mass despite a negative energy balance. ...
Article
Full-text available
Background Resting metabolic rate (RMR) has been examined as a proxy for low energy availability (EA). Previous studies have been limited to adult athletes, despite the serious health consequences of low EA, particularly during adolescence. This study aimed to explore the relationship between RMR and EA in competitive teenage girl runners. Methods Eighteen girl runners (mean ± standard-deviation; age, 16.8 ± 0.9 years; body mass, 45.6 ± 5.2 kg, %fat, 13.5 ± 4.2 %) in the same competitive high-school team were evaluated. Each runner was asked to report dietary records with photos and training logs for seven days. Energy intake (EI) was assessed by Registered Dietitian Nutritionists. The runners were evaluated on a treadmill with an indirect calorimeter to yield individual prediction equations for oxygen consumption using running velocity and heart rate (HR). Exercise energy expenditure (EEE) was calculated by the equations based on training logs and HR. Daily EA was calculated by subtracting EEE from EI. The daily means of these variables were calculated. RMR was measured early in the morning by whole-room calorimetry after overnight sleep on concluding the final day of the seven-day assessment. The ratio of measured RMR to predicted RMR (RMR ratio) was calculated by race, age, sex-specific formulae, and Cunningham’s equation. Body composition was measured using dual-energy X-ray absorptiometry. Bivariate correlation analyses were used to examine the relationship between variables. Results RMR, EI, EEE, and EA were 26.9 ± 2.4, 56.8 ± 15.2, 21.7 ± 5.9, and 35.0 ± 15.0 kcal⋅kg ⁻¹ FFM⋅d ⁻¹ , respectively. RMR reduced linearly with statistical significance, while EA decreased to a threshold level (30 kcal⋅kg ⁻¹ FFM⋅d ⁻¹ ) ( r= 0.58, p= 0.048). Further reduction in RMR was not observed when EA fell below the threshold. There was no significant correlation between RMR ratios and EA, irrespective of the prediction formulae used. Conclusions These results suggest that RMR does not reduce with a decrease in EA among highly competitive and lean teenage girl runners. RMR remains disproportionally higher than expected in low EA states. Free-living teenage girl runners with low EA should be cautiously identified using RMR as a proxy for EA change.
... There were no significant differences in resting metabolic rate between the two groups, suggesting that as long as the caloric restriction is not severe, that relatively high protein is consumed, and resistance training is performedadverse metabolic adaptations can be minimized regardless of a flexible or rigid dietary approach to caloric restriction [38][39][40]. Both treatment groups displayed high levels of cognitive restraint during the diet phase. ...
Article
Full-text available
Background The purpose of this study was to compare a flexible vs. rigid diet on weight loss and subsequent weight regain in resistance-trained (RT) participants in a randomized, parallel group design. Methods Twenty-three males and females (25.6 ± 6.1 yrs; 170 ± 8.1 cm; 75.4 ± 10.3 kg) completed the 20-week intervention (consisting of a 10-week diet phase and a 10-week post-diet phase). Participants were randomized to a flexible diet (FLEX) comprised of non-specific foods or a rigid diet (RIGID) comprised of specific foods. Participants adhered to an ~20%kcal reduction during the first 10-weeks of the intervention and were instructed to eat ad libitum for the final 10-weeks. Body composition and resting metabolic rate were assessed 5 times: (baseline, 5, 10 [end of diet phase], 16, and 20 weeks). Results During the 10-week diet phase, both groups significantly reduced bodyweight (FLEX: baseline = 76.1 ± 8.4kg, post-diet = 73.5 ± 8.8 kg, ▲2.6 kg; RIGID: baseline = 74.9 ± 12.2 kg, post-diet = 71.9 ± 11.7 kg, ▲3.0 kg, p < 0.001); fat mass (FLEX: baseline = 14.8 ± 5.7 kg, post-diet = 12.5 ± 5.0 kg, ▲2.3 kg; RIGID: baseline = 18.1 ± 6.2 kg, post-diet = 14.9 ± 6.5 kg, ▲3.2 kg p < 0.001) and body fat% (FLEX: baseline = 19.4 ± 8.5%, post-diet = 17.0 ± 7.1%, ▲2.4%; RIGID: baseline = 24.0 ± 6.2%, post-diet = 20.7 ± 7.1%, ▲3.3%; p < 0.001). There were no significant differences between the two groups for any variable during the diet phase. During the post-diet phase, a significant diet x time interaction ( p < 0.001) was observed for FFM with the FLEX group gaining a greater amount of FFM (+1.7 kg) in comparison with the RIGID group (−0.7 kg). Conclusions A flexible or rigid diet strategy is equally effective for weight loss during a caloric restriction diet in free-living, RT individuals. While post-diet FFM gains were greater in the FLEX group, there were no significant differences in the amount of time spent in resistance and aerobic exercise modes nor were there any significant differences in protein and total caloric intakes between the two diet groups. In the absence of a clear physiological rationale for increases in FFM, in addition to the lack of a standardized diet during the post-diet phase, we refrain from attributing the increases in FFM in the FLEX group to their diet assignment during the diet phase of the investigation. We recommend future research investigate additional physiological and psychological effects of flexible diets and weight regain in lean individuals.
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Body fat and muscle mass showed opposing associations with mortality. The results of research on the effectiveness of popular body mass (BM) loss diets in obese subjects showed 20 to 30% loss of muscle mass within the total BM loss; conversely, when the subjects used a whole-food, plant-based (WFPB) diet, the loss was up to 42%. Therefore, we suggest an improvement. The aim of this retrospective analysis of data was to examine the assessment of changes in the body composition of 217 participants from all over Slovenia who joined our ongoing, community-based WFPB lifestyle programme from 2016 to 2021 and underwent two successive measurements of medically approved bioelectrical impedance. The WFPB lifestyle programme consisted of (i) nutrition, (ii) physical activity (PA) and (iii) a support system. The primary outcomes included the (vector of) change of body fat mass (BFM) per body height (BH), fat-free mass (FFM) per BH and whole-body phase angle (PhA) from the initial values to the first follow-up (FU) of the whole sample and for both sexes. Further, we examined the FFM change within the total BM loss according to their BMI classification and depending on how much BM they lost (5 kg < BM ≥ 5 kg) within the FU time (103.6 ± 89.8 day). Participants experienced a decrease in BFM per BH (−0.02 ± 0.02 kg/cm, p < 0.001), no change in FFM and an increase in PhA (0.2 ± 0.7°, p < 0.001). Importantly, the participants in the obesity BMI class achieved only partial FFM preservation (−1.5 ± 3.6 kg, p = 0.032 of FFM loss (20%) within −7.5 ± 6.1 kg, p < 0.001 of BM loss). However, the participants who lost BM < 5 kg had a significantly increased FFM (0.8 ± 3.2 kg, p = 0.001 of FFM (57%) within −1.4 ± 1.8 kg, p < 0.001 of BM loss), whereas the participants who lost BM ≥ 5 kg experienced a decrease in FFM (−2.2 ± 3.9 kg, p < 0.001 of FFM (−25%) within −8.8 ± 5.2 kg, p < 0.001 of BM loss). To conclude, the WFPB lifestyle, on average, effectively preserved FFM during BM and/or BFM loss among the normal and pre-obesity BMI classes but only partially among the obese BMI class and those who lost ≥ 5 kg of BM. Importantly, a customized PA strategy is needed for obese BMI class participants, where general resistance training is not possible or safe in order to preserve their muscle mass more effectively. In addition, muscle mass preservation is important for further improvements of BM, body composition and visual body image.
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Background Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown.Objectives This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat.DesignSystematic review with meta-analysis.Data SourcesWe searched five electronic databases up to January 2021.Eligibility CriteriaWe included randomised trials that compared full-body resistance training for at least 4 weeks to no-exercise control in healthy adults.AnalysisWe assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components.ResultsFrom 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6–15). Compared to the control, resistance training reduced body fat percentage by − 1.46% (95% confidence interval − 1.78 to − 1.14, p < 0.0001), body fat mass by − 0.55 kg (95% confidence interval − 0.75 to − 0.34, p < 0.0001) and visceral fat by a standardised mean difference of − 0.49 (95% confidence interval − 0.87 to − 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size.Summary/Conclusions Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults.Study Registrationosf.io/hsk32.
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Weight loss can have substantial health benefits for overweight or obese persons; however, the ratio of fat:lean tissue loss may be more important. We aimed to determine how daily exercise (resistance and/or aerobic) and a hypoenergetic diet varying in protein and calcium content from dairy foods would affect the composition of weight lost in otherwise healthy, premenopausal, overweight, and obese women. Ninety participants were randomized to 3 groups (n = 30/group): high protein, high dairy (HPHD), adequate protein, medium dairy (APMD), and adequate protein, low dairy (APLD) differing in the quantity of total dietary protein and dairy food-source protein consumed: 30 and 15%, 15 and 7.5%, or 15 and <2% of energy, respectively. Body composition was measured by DXA at 0, 8, and 16 wk and MRI (n = 39) to assess visceral adipose tissue (VAT) volume at 0 and 16 wk. All groups lost body weight (P < 0.05) and fat (P < 0.01); however, fat loss during wk 8-16 was greater in the HPHD group than in the APMD and APLD groups (P < 0.05). The HPHD group gained lean tissue with a greater increase during 8-16 wk than the APMD group, which maintained lean mass and the APLD group, which lost lean mass (P < 0.05). The HPHD group also lost more VAT as assessed by MRI (P < 0.05) and trunk fat as assessed by DXA (P < 0.005) than the APLD group. The reduction in VAT in all groups was correlated with intakes of calcium (r = 0.40; P < 0.05) and protein (r = 0.32; P < 0.05). Therefore, diet- and exercise-induced weight loss with higher protein and increased dairy product intakes promotes more favorable body composition changes in women characterized by greater total and visceral fat loss and lean mass gain.
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The aim of the present study was to compare the effects of 10 weeks resistance training in combination with either a regular diet (Ex) or a low carbohydrate, ketogenic diet (Lc+Ex) in overweight women on body weight and body composition. 18 untrained women between 20 and 40 years with BMI >/= 25 kg*m-2 were randomly assigned into the Ex or Lc+Ex group. Both groups performed 60-100 min of varied resistance exercise twice weekly. Dietary estimates were based on two 4-day weighed records. Body composition was estimated using Dual Energy X-ray Absorptiometry. Fasting blood samples were analyzed for total-, HDL- and LDL-cholesterol, triacylglycerols, and glucose. 16 subjects were included in the analyses. Percentage of energy (En%) from carbohydrates, fat and protein was 6, 66, and 22 respectively in the (Lc+Ex) group and 41, 34, 17 in the Ex group. Mean weight change (pre-post) was -5.6 +/- 2.6 kg in Lc+Ex; (p < 0.001) and 0.8 +/- 1.5 kg in Ex; (p = 0.175). The Lc+Ex group lost 5.6 +/- 2.9 kg of fat mass (p = 0.001) with no significant change in lean body mass (LBM), while the Ex group gained 1.6 +/- 1.8 kg of LBM (p = 0.045) with no significant change in fat mass (p = 0.059). Fasting blood lipids and blood glucose were not significantly affected by the interventions. Resistance exercise in combination with a ketogenic diet may reduce body fat without significantly changing LBM, while resistance exercise on a regular diet may increase LBM in without significantly affecting fat mass. Fasting blood lipids do not seem to be negatively influenced by the combination of resistance exercise and a low carbohydrate diet.
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Recent guidelines on exercise for weight loss and weight maintenance include resistance training as part of the exercise prescription. Yet, few studies have compared the effects of similar amounts of aerobic and resistance training on body mass and fat mass in overweight adults. STRRIDE AT/RT, a randomized trial, compared aerobic training, resistance training and a combination of the two to determine the optimal mode of exercise for obesity reduction. Participants were 119 sedentary, overweight or obese adults who were randomized to one of three 8-month exercise protocols: 1) RT: resistance training; 2) AT: aerobic training; and 3) AT/RT: aerobic and resistance training (combination of AT and RT). Primary outcomes included total body mass, fat mass and lean body mass. The AT and AT/RT groups reduced total body mass and fat mass more than RT (p<0.05), but they were not different from each other. RT and AT/RT increased lean body mass more than AT (p<0.05). While requiring double the time commitment, a program of combined AT and RT did not result in significantly more fat mass or body mass reductions over AT alone. Balancing time commitments against health benefits, it appears that AT is the optimal mode of exercise for reducing fat mass and body mass while a program including RT is needed for increasing lean mass in middle-aged, overweight/obese individuals.
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The specific resting metabolic rates (K(i) , in kcal/kg per day) of major organs and tissues in the Reference Man were suggested in 1992 by Elia: 200 for liver, 240 for brain, 440 for heart and kidneys, 13 for skeletal muscle, 4.5 for adipose tissue and 12 for the residual mass. However, it is unknown whether gender influences the K(i) values. The aim of the present study was to compare the K(i) values observed in nonelderly nonobese men to the corresponding values in women. Elia's K(i) values were evaluated based on a mechanistic model: REE = Σ(K(i) × T(i) ), where REE is whole-body resting energy expenditure measured by indirect calorimetry and T(i) is the mass of major organs and tissues measured by magnetic resonance imaging. Marginal 95% confidence intervals (CIs) for the model-estimated K(i) values were calculated by stepwise univariate regression analysis. Subjects were nonelderly (age 20-49 years) nonobese (BMI 18.5-29.9 kg/m(2) ) men (n = 49) and women (n = 57). The measured REE (REEm) and the mass of major organs and skeletal muscle were all greater in the men than in women. The predicted REE by Elia's K(i) values were correlated with REEm in men (r = 0.87) and women (r = 0.86, both P < 0.001). Elia's K(i) values were within the range of 95% CIs for both men and women groups, revealing that gender adjustment is not necessary. Elia's proposed adult K(i) values are valid in both nonelderly nonobese men and women. Further studies are needed to explore the potential influences of age and obesity on K(i) values in humans.