Changes in leptin and peptide YY do not explain the greater than predicted decreases in resting energy expenditure after weight loss

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Jessica McNeil, Assistant Professor (Creator)
The University of North Carolina at Greensboro (UNCG )
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Abstract: Context: It is unknown whether leptin and peptide YY (PYY) influence changes in resting energy expenditure (REE), independently of fat mass (FM) and fat-free mass (FFM) in addition to changes in other energy expenditure (EE) components during weight loss. Objective: The objective of the study was to examine the relationships between leptin, PYY, and body composition with different EE components before and after weight loss and whether changes in leptin and PYY were associated with differences in predicted vs measured REE after the intervention. Design: This was a randomized controlled design. Setting: The study was conducted in a laboratory. Participants: Participants were ninety-three overweight/obese postmenopausal women (aged 58.1 ± 4.8 y; body mass index 32.1 ± 4.3 kg/m2). Intervention: Interventions included a 6-month caloric restriction diet alone or caloric restriction diet+resistance training. Main Outcome Measures: Body composition (dual energy x-ray absorptiometry), REE (indirect calorimetry), total EE (TEE; doubly labeled water), and fasting leptin and total PYY before and after weight loss were measured. Results: Both interventions yielded significant decreases in weight, FFM, REE, and leptin, whereas a significant time × group interaction was noted for FM (greater decrease in FM in the diet+resistance training group) (P < .05 for all outcomes). No significant differences in TEE, physical activity EE, and PYY were noted between baseline and after the intervention. Age, FFM, leptin, and PYY were the best predictors of baseline REE (R2 = 0.77; P = .0001), whereas age, FFM, and FM were associated with REE after the intervention (R2 = 0.88; P = .0001). The same predictors, except for leptin, were significantly related to TEE at baseline (R2 = 0.70; P = .0001) and after the intervention (R2 = 0.29; P = .0001), whereas only PYY was a significant predictor of physical activity EE at baseline and after the intervention. Changes in FM and leptin accounted for 27% of the variance in delta-REE (P = .0001). Greater predicted vs measured REE was noted after the intervention (P = .02). However, delta-leptin and delta-PYY were not significant predictors of the differences between postintervention measurement and predicted REE. Conclusions: delta-Leptin and delta-FM were strong contributors to changes in REE. However, delta-leptin and delta-PYY were not significant predictors of the differences between predicted and measured REE after the intervention.

Additional Information

Journal of Clinical Endocrinology and Metabolism, 2015, 100(3): E443-452
Language: English
Date: 2015
resting energy expenditure, weight loss, leptin, peptide YY

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