Implementation of weekday time-restricted eating to improve metabolic health in breast cancer survivors with overweight/obesity

Abstract

Objective: This study aimed to evaluate the implementation of telephone-based delivery of weekday-only time-restricted eating (TRE), its preliminary efficacy for metabolic outcomes, and concurrent lifestyle changes. Methods: Twenty-two breast cancer survivors aged 60+ years with overweight/obesity completed an 8-week feasibility study of 12 to 8 p.m. weekday-only ad libitum TRE. The intervention was delivered by one registered dietitian call, twice-daily automated text messages asking about eating start and stop times, and three support phone calls. Magnetic resonance imaging, venipuncture, and 3 days of diet records and accelerometry were performed at baseline and after intervention. Results: Participants had a mean age of 66 (SD 5) years with BMI of 31.8 (4.8) kg/m2. Intervention implementation was successful, including excellent adherence (98%), participant acceptability, and a low symptom profile and cost ($63/participant). There were no significant changes in individual components of metabolic syndrome, lipid profile, or hemoglobin A1c, despite clinically relevant changes occurring within individual participants. Magnetic resonance imaging–derived hepatic steatosis and thigh myosteatosis did not change. Dietary intake changes included reduced energy (−22%) and protein (−0.2 g/kg). Physical activity and sleep did not change. Conclusions: Eight weeks of telephone-delivered weekday TRE is a feasible, acceptable, low-symptom, and low-cost intervention. Future studies may consider a longer intervention length for more consistent metabolic improvements and counseling to enhance protein intake.