scholarly journals Influence of fat-free mass and resting metabolic rate on increased food reinforcement after exercise training

Author(s):  
Christopher L. Pankey ◽  
Kyle Flack ◽  
Kelsey Ufholz ◽  
LuAnn Johnson ◽  
James N. Roemmich

Abstract Purpose Models of appetite control have been largely based on negative feedback from gut and adipose signaling to central appetite centers. However, contemporary models posit that fat-free mass (FFM) or the energy demand of FFM [i.e., resting metabolic rate (RMR)] may play a primary role in the motivational drive for food intake (i.e., food reinforcement). The relative reinforcing value of food (RRVfood) is associated with energy intake (EI) and increases with an acute energy deficit. Chronic exercise-induced energy deficits lead to alterations in fat mass (FM), FFM, and RMR and provide an opportunity to test whether change in (∆) FM, ∆FFM, ∆usual EI, or ∆RMR are associated with ∆RRVfood. Methods Participants (n = 29, BMI = 25–35 kg/m2) engaged in aerobic exercise expending 300 or 600 kcal, 5 days/weeks for 12 weeks. The reinforcing value of food (PMaxfood) was measured via a computer-based operant responding task and RRVfood was calculated as the reinforcing value of food relative to non-eating sedentary behaviors. RMR was determined by indirect calorimetry and body composition by DXA. Results Post-training FFM correlated with usual post-training EI (rs = 0.41, p < 0.05), PMaxfood (rs=0.52, p < 0.01), and RMR (rs = 0.85, p < 0.0001). ∆RMR negatively correlated with ∆PMaxfood (rs = − 0.38, p < 0.05) and with ∆RRVfood (rs = − 0.37, p < 0.05). ∆PMaxfood and ∆RRVfood were not associated with ∆FFM (p = 0.71, p = 0.57, respectively). Conclusions Reductions in RMR with weight loss may increase food reinforcement as means of restoring FFM and RMR to pre-weight loss amounts. Limiting reductions in RMR during weight loss may benefit weight maintenance by restricting increases in food reinforcement after weight loss.

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 526-526
Author(s):  
Rachel Silver ◽  
Sai Das ◽  
Michael Lowe ◽  
Susan Roberts

Abstract Objectives There is persistent controversy over the extent to which different components of energy expenditure disproportionately decrease after weight loss and contribute to weight regain through decreased energy requirements. We conducted a secondary analysis of the CALERIE I study to test the hypothesis that decreased resting metabolic rate (RMR) and energy expenditure for physical activity (EEPA) after a 6-month calorie restriction intervention would predict weight regain at 12 months, with a greater decrease in RMR than EEPA. Methods Participants (n = 46) received all food and energy-containing beverages for 6 months. Outcome measures included total energy expenditure by doubly labeled water, RMR by indirect calorimetry, and body composition by BOD POD. Predictions for RMR and EEPA were derived from baseline linear regression models including age, sex, fat mass, and fat free mass. Baseline regression coefficients were used to calculate the predicted RMR and EEPA at 6 months. Residuals were calculated as the difference between measured and predicted values and were adjusted for body weight. The presence of metabolic adaptation was evaluated by a paired t-test comparing measured and predicted RMR at 6 months. Differences between 6-month RMR and EEPA residuals were evaluated by the same method. Linear regression was used to assess the association between 6-month residuals and weight loss maintenance (% weight change, 6 to 12 months). Results Mean weight loss was 6.9% at 6 months with 2.1% regain from 6 to 12 months. No adaptation in RMR was observed at 6 months (mean residual: 19 kcal; 95% confidence interval: −9, 48; P = 0.18). However, significant adaptation was observed in EEPA (mean residual: −199 kcal; −126, −272; P &lt; 0.0001). In addition, the mean 6-month RMR residual was significantly greater than the mean 6-month EEPA residual (218 kcal; 133, 304; P &lt; 0.0001). There was no significant association between 6-month RMR or EEPA residuals and weight regain at 12 months (P = 0.56, 0.34). Conclusions There was no measurable decrease in RMR with weight loss after adjusting for changes in fat free mass and fat mass, but there was a decrease in EEPA. Changes in RMR and EEPA with weight loss over 6 months did not predict weight regain at 12 months. Funding Sources Jean Mayer USDA Human Nutrition Research Center on Aging Doctoral Scholarship; USDA agreement #8050–51000-105–01S


2000 ◽  
Vol 84 (4) ◽  
pp. 515-520 ◽  
Author(s):  
R. Menozzi ◽  
M. Bondi ◽  
A. Baldini ◽  
M. G. Venneri ◽  
A. Velardo ◽  
...  

The reduction in resting metabolic rate (RMR) during weight loss exceeds that accounted for by changes in body composition by 15%, suggesting that factors other than fat-free mass (FFM) explain the metabolic adaptation during food restriction in obesity. Our study aimed to establish if changes in the sympathoadrenal system activity, as inferred from an integrated measure such as 24 h urinary excretion of catecholamines, may play a role in the RMR adaptation observed during dietary restriction in obese patients. Ninety-three obese female subjects consumed a low-energy diet (LED) (2930 kJ/d (700 kcal/d)) for a 3-week period. At the beginning and at the end of the study, 24 h urinary excretion of catecholamines, FFM and RMR were measured. The LED induced a significant reduction in body weight (-3·3 (SEM 0·4) KG; P < 0·01), FFM (-1·9 (sem 0·7) kg; P < 0·01) and in the fat mass (-1·2 (sem 0·5) kg; P < 0·01). Noradrenalin excretion (24 h) decreased during the LED from 264 (sem 26) during a weight-maintenance period to 171 (sem 19) nmol/24 h after consumption of the LED for 3 weeks (P < 0·001); mean 24 h adrenalin excretion did not change during the LED (22 (sem 3) during the weight-maintenance period v. 21 (sem 3) nmol/24 h after consumption of the LED for 3 weeks; NS). The LED induced a significant decrease in RMR (7300 (sem 218) v. 6831 (sem 138) kJ/24 h; P < 0·001). The only independent variable that significantly explained variations in RMR both before and after consumption of the LED for 3 weeks, was FFM (r2 0·79 and r2 0·80 respectively). Urinary noradrenalin excretion explained a further 4 % of the variability in RMR, but only before the diet, so that a role of sympathoadrenal system on RMR seems to be present in obese patients in basal conditions but not at the end of the LED.


2015 ◽  
Vol 152 ◽  
pp. 473-478 ◽  
Author(s):  
J.E. Blundell ◽  
G. Finlayson ◽  
C. Gibbons ◽  
P. Caudwell ◽  
M. Hopkins

2017 ◽  
Vol 42 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Angela S. Alberga ◽  
Denis Prud’homme ◽  
Ronald J. Sigal ◽  
Gary S. Goldfield ◽  
Stasia Hadjiyannakis ◽  
...  

We evaluated the hypothesis that resistance exercise training performed alone or in combination with aerobic exercise training would increase resting metabolic rate (RMR) relative to aerobic-only and nonexercising control groups. Postpubertal adolescents (N = 304) aged 14–18 years with obesity (body mass index (BMI) ≥ 95th percentile) or overweight (BMI ≥ 85th percentile + additional diabetes risk factor(s)) were randomized to 4 groups for 22 weeks: Aerobic exercise training, Resistance exercise training, Combined aerobic and resistance exercise training, or Control. All participants received dietary counselling targeting a daily energy deficit of 250 kcal. RMR was measured by indirect calorimetry and body composition by magnetic resonance imaging. There was no significant change in RMR in any group, in spite of significant within-group increases in fat-free mass in the Aerobic, Resistance, and Combined exercise training groups. RMR at baseline and 6 months were Aerobic: 1972 ± 38 and 1990 ± 41; Resistance: 2024 ± 37 and 1992 ± 41; Combined: 2023 ± 38 and 1995 ± 38; Control: 2075 ± 38 and 2073 ± 39 kcal/day (p > 0.05). There were no between-group differences in RMR after adjustment for total body weight or fat-free mass between groups over time. Per-protocol analyses including only participants with ≥70% adherence, and analyses stratified by sex, also showed no within- or between-group differences in RMR. In conclusion, despite an increase in fat-free mass in all exercise groups, 6 months of aerobic, resistance, or combined training with modest dietary restriction did not increase RMR compared with diet only in adolescents with obesity.


1994 ◽  
Vol 77 (2) ◽  
pp. 933-940 ◽  
Author(s):  
K. E. Friedl ◽  
R. J. Moore ◽  
L. E. Martinez-Lopez ◽  
J. A. Vogel ◽  
E. W. Askew ◽  
...  

We examined body composition changes in 55 normal young men during an 8-wk Army combat leadership training course involving strenuous exercise and low energy intake, with an estimated energy deficit of 5.0 +/- 2.0 MJ/day and a resultant 15.7 +/- 3.1% weight loss. Percent body fat (BF) measured by dual-energy X-ray absorptiometry (DEXA) averaged 14.3% (range 6–26%) and 5.8 +/- 1.8% (range 4–11%) at the beginning and end of the course, respectively. Men who achieved a minimum percent BF (4–6%) by 6 wk demonstrated only small additional total and subcutaneous fat losses in the final 2 wk and sacrificed increasingly larger proportions of fat-free mass. Percent BF estimated from skinfold thicknesses reflected relative changes in fat mass, although actual percent BF was overestimated. Instead of reaching a plateau after fat stores were substantially depleted, abdominal, hip, and thigh girths continued to decline with body weight loss. Final percent BF for the leanest men was similar to that observed after a 25% body weight reduction in the 1950 Minnesota study (5.2% by underwater weighting), and height-corrected final fat mass was the same (1.0 +/- 0.2 vs. 0.9 +/- 0.7 kg fat/m2), suggesting that these values represent a minimal body fat content in healthy men and that weight loss subsequent to achieving this level is contributed from the fat-free mass. Our results suggest that 4–6% BF or approximately 2.5 kg fat represents the lower limit for healthy men, as assessed by DEXA or by underwater weighing.


2020 ◽  
Author(s):  
Seyedeh Forough Sajjadi ◽  
Atieh Mirzababaei ◽  
nasim Ghodoosi ◽  
Sara Pooyan ◽  
Hana Arghavani ◽  
...  

Abstract Objective Resting metabolic rate (RMR) accounts for most of the daily energy expenditure. The low-carb diet attenuates decreases in RMR. This study aims to investigate the relationship between a low-carb diet and resting metabolic rate status. Methods We enrolled 304 overweight and obese women in this cross-sectional study. BMI, fat mass, fat-free mass, visceral fat, insulin level were assessed. RMR was measured using indirect calorimetry. A low carbohydrate diet score was measured using a validated semi-quantitative food frequency questionnaire (FFQ). Results Our results showed no relationship between LCDS and DNR even after adjust for confounders (Inc. RMR: OR: 0.97; 95% CI: 0.92–1.01, P = 0.20; Dec. RMR: OR: 0.97; 95% CI: 0.94-1.00, P = 0.14). Some components of LCDS had significant differences with DNR, such as carbohydrate and Dec. RMR in adjusted model (OR: 1.62; 95% CI: 0.98–1.37, P = 0.08), MUFA and Dec. RMR in adjusted model (OR: 0.48; 95% CI: 0.21–1.10, P = 0.08) and refined grain and Inc. RMR in crude model (OR: 0.87; 95% CI: 0.77–0.99, P = 0.04). Conclusion Our study showed that there is no association between a low-carb diet and RMR status but carbohydrate, MUFA, and refined grain had a significant relationship.


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