Pilot Study of Time Restricted Feeding as a Weight Loss Intervention

The circadian timing of Energy Intake (EI) has emerged as a key factor in the regulation of body weight. Studies have suggested that eating later in the evening or at night when the circadian system is promoting sleep adversely influences weight loss. In contrast, restricting EI to a short window during waking hours and extending the length of the overnight fast (i.e., time restricted feeding, TRF) may be a practical and useful weight loss strategy. The overall objective of this proposal is to provide a foundation to inform the design of a future large-scale trial to evaluate the efficacy of TRF in generating weight loss. The investigators aims are to: 1) Assess processes critical for the success of a large-scale trial comparing the efficacy of a reduced calorie diet with time restricted feeding (RCD+TRF) versus standard RCD on weight loss; 2) Develop methodology to assess compliance to the RCD+TRF versus standard RCD program and collect preliminary data on whether the programs have differential effects on free-living behaviors (EI, appetite, physical activity, and sedentary behavior); and 3) Measure metabolic responses to RCD+TRF versus standard RCD to determine candidate mechanisms related to weight loss at 12wks and weight maintenance at 6mo post-intervention. The investigators primary hypothesis is that weight loss will be greater in the TRF group compared to the RCD group.