0019 Body Weight Reduction Following 8-weeks of Time-restricted Eating in Peri- and Postmenopausal Women with Obesity

Abstract Introduction Many women experience weight gain due to hormonal changes during menopause. Time-restricted eating (TRE) has been proposed as a dietary intervention to reduce body weight but has not been studied extensively during the menopause transition. We aimed to test the effect of TRE on body weight and composition in peri- and recently (< 5 yrs) postmenopausal women with obesity. Methods Participants were recruited from the New England area. To date, 23 women (mean age±SD: 51.9±4.1 yrs; mean BMI±SD: 34.9±3.2 kg/m2) have been randomized to 8-weeks of unrestricted eating (URE; n=11) or TRE (n=12), where participants were instructed to consume calories only during a self-selected 8-hour eating window each day (e.g., 10 am-6 pm). Outcomes included body weight, body composition [fat, fat-free and visceral adipose tissue (VAT) mass, measured via dual x-ray absorptiometry], and 7-day caloric intake [kCal/day; per MealloggerTM app with time-stamp]. Change from baseline to post-intervention was compared between the groups using t-tests. Results On average, the TRE eating window was 4.1±0.7 (95%CI 2.7 to 5.6) hours shorter than the URE group (p< 0.001; 7.1±0.2 vs. 11.2±0.7 hours, respectively). Compliance with the daily 8-hour TRE eating window (average compliance 93±6.9% of days) and acceptability (11/12 planned to continue TRE after study completion) were high. Despite no statistically significant between-group difference in calorie intake (1515.8±561.7 vs 1430.0±419.6 kCal/day), the TRE group lost an average of 2.4±0.6 kg (SD), significantly more than the URE group who gained an average of 0.46±0.4 kg (p< 0.01; mean difference=2.8±0.7, 95%CI -4.4 to -1.3). Furthermore, there was a trend toward a greater reduction in fat mass in the TRE (-0.7±0.4 kg) compared to URE group (0.65±0.6 kg) (p=0.059; mean difference=1.4±0.7 kg, 95%CI -2.8 to 0.06). Change in fat-free and VAT mass did not differ. Conclusion In this interim analysis of an ongoing trial, 8 weeks of TRE led to a reduction in body weight and possibly fat mass in peri- and postmenopausal women with obesity. Importantly, compliance and acceptability of the diet were high, suggesting that the intervention is feasible and sustainable in this population. Support (if any) BWH and Bayer Pharmaceuticals supporting U54AG062322; BWH Pollin Research Award; WHAM Edge Award