LAUSR

Objectives Time restricted feeding (TRF) is a novel approach to intermittent fasting which includes a 4-10 hour feeding window and a 14-20 hour fasting window daily. However, the safety of TRF has yet to be determined. This study was undertaken to determine the effects of TRF on certain safety parameters, including: eating disorder symptoms, body image perception, complete blood count, resting metabolic rate, and frequency of adverse events, in adults with obesity. Methods Adults with obesity (n = 23) participated in an 8-h TRF intervention (ad libitum feeding between 10:00 to 18:00 h, water fasting between 18:00 to 10:00 h) for 12 weeks. Results Body weight significantly (P < 0.001) decreased by 2.6 ± 0.5% after 12 weeks of TRF. Resting metabolic rate did not change over time (baseline: 1431 ± 62 kcal/d; week 1: 1393 ± 82 kcal/d; week 12: 1318 ± 61 kcal/d). Self-reported adverse events (gastrointestinal or neurological) did not change over time. Eating disorder symptoms including depression, binge eating, purgative behavior, fear of fatness, restrictive eating, and avoidance of forbidden foods, did not change from baseline to week 12. Concerns about body size and shape remained unchanged. Cognitive restraint, uncontrolled eating and emotional eating did not change over time. There were no significant changes in any of the complete blood count parameters from baseline to week 12. Conclusions This study is the first to show that TRF is a safe diet therapy for weight loss as it does not negatively impact eating disorder symptoms, eating behaviors, resting metabolic rate, or measures of overall health, such as complete blood count. Funding Sources University of Illinois Chicago Campus Research Board Pilot Grant; NIH T32HL007909.