555-P: Premenopausal vs. Postmenopausal Women: Effect of Time-Restricted Eating on Body Weight and Metabolic Health Markers

Background: Time restricted eating (TRE) involves restricting the ad libitum eating window to a specific number of hours daily, while water fasting for the remaining hours.

Objective: This study examined if changes in body weight and metabolic risk factors during TRE, differ in women based on menopausal status. Methods: This is a secondary analysis of an 8-week TRE study (4-6 h eating window, 18-20 h fasting window daily) conducted in adults with obesity. Male participants were excluded, and female subjects were classified in two groups based on menstrual status: premenopausal (n = 13) , or postmenopausal (n = 19) . Perimenopausal women were excluded from the original study.

Results: Body weight decreased in both premenopausal women (-3.3 ± 0.4%) and postmenopausal women (-3.3 ± 0.5%) (main effect of time, P < 0.001) , with no difference between groups (no group × time interaction) by week 8. Adherence in both groups was very high, with premenopausal women adhering to their prescribed eating window on 6.2 ± 0.1 d/week, and postmenopausal women adhering to their window on 6.2 ± 0.2 d/week. Fat mass, lean mass, fasting insulin, insulin resistance, and 8-isoprostane (marker of oxidative stress) were reduced similarly in both groups (main effect of time, P < 0.for all comparisons) . Visceral fat mass, relative skeletal muscle index (RSMI) , blood pressure, LDL cholesterol, HDL cholesterol, triglycerides, fasting glucose, HbA1c, TNF-alpha and IL-6 remained unchanged by 8 weeks in both groups.

Conclusion: These findings suggest that the weight loss and metabolic benefits of TRE do not differ between premenopausal and postmenopausal women with obesity.