0002 Impact of Acute, Isocaloric Time-Restricted Eating on Resting Metabolic Rate and Obesogenic Factors in Healthy Lean Adults

Abstract Introduction Time-restricted eating (TRE) is a dietary strategy in which energy consumed over 6-10h window during the day and associated with reduced intake subsequent weight loss people obesity. However, impact of isocaloric TRE on obesogenic factors such as hormones related to hunger appetite, well expenditure metabolic rate relatively unknown. We therefore investigated 1 week obesity-related outcomes including circulating leptin, ghrelin, peptide YY (PYY) resting (RMR). Methods Thirteen healthy adults (8F, 26.9±3.9y, 23.3±2.1kg/m2) participated 2-week protocol. During Week 1, was 13h period meals individually anchored habitual wake time at +1h, +6h, +11h +14h after wake. For 2, participants were instructed match from but restrict an 8h (meals +5h, +9h wake). At end each week, admitted laboratory for overnight stay. Blood samples collected hourly assayed PYY. RMR assessed using hood calorimetry immediately Results significant reduction leptin levels (p< 0.001) without changes body (p=0.536), PYY or ghrelin levels. The respiratory exchange ratio (RER) calculated significantly lower (0.76 vs 0.81; p=0.04) despite no change (p=0.478) suggesting higher reliance fat oxidation compared eating. Conclusion Reductions conjunction RER suggests that promotes increased utilization Future studies should evaluate whether long-term adipose tissue mass. Support (if any) This project supported by R01DK125653.