A controlled trial of 54 overweight college students found that combining 10-hour daily eating windows with resistance training yielded superior fat loss (3.2kg) compared to either intervention alone over 8 weeks. Time-restricted eating alone reduced body weight but also decreased lean muscle mass by 2.3kg, while resistance training alone preserved muscle while cutting 1.1kg of fat. The combination approach maintained muscle mass while achieving the greatest fat reduction.
This finding addresses a critical limitation in intermittent fasting research, where muscle preservation during weight loss remains poorly understood. The results align with emerging evidence that protein timing and resistance stimulus become more crucial during caloric restriction periods. For health-conscious adults considering time-restricted eating, the data suggest that without concurrent strength training, significant muscle loss may offset metabolic benefits. The study's 8-week duration and young participant demographic limit broader applicability, but the mechanistic insight—that eating windows alone trigger both fat and muscle loss—has important implications for designing sustainable body composition interventions. The research reinforces that effective fat loss strategies require addressing both energy balance and muscle protein synthesis simultaneously.