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.
|Journal||Sport Sciences for Health|
|State||Published - Sep 2022|
Bibliographical noteFunding Information:
CLP: Lead author—Led study idea development, ran statistical analyses, and composed manuscript draft. KDF: Second author—Led study design and development, all aspects of recruitment, intervention management, and data collection. Assisted in manuscript revision. KEU: Third author—Assisted in data collection and revision of manuscript. LAJ: Fourth author—Statistician contributing to statistical analyses. JNR: Senior author—Led project development, study design, and responsible for funding. Assisted in manuscript revision and made final decisions on manuscript and data analysis. All authors have approved the final version of the manuscript.
This work was supported by the United States Department of Agriculture, Agricultural Research Service, project 3062-51000-051-00D
© 2021, The Author(s).
- Body composition
- Energy homeostasis
- Food reinforcement
- Resting metabolic rate
- Weight loss
ASJC Scopus subject areas
- Orthopedics and Sports Medicine