Abstract
Time-restricted feeding (TRF) aligned with an organism's circadian rhythm has been shown to improve health, but its long-term effects on healthspan and lifespan in mammals, especially under normal dietary conditions, remain unclear. In this study, we tested the impact of 12-hour (h) and 8h nightly TRF windows on aging in male and female mice fed regular chow. TRF improved several health measures, including the regularity of behavioral patterns, body weight and composition, frailty, and disease onset, with stronger effects observed in the 8h-TRF group, which self-imposed a caloric restriction. When integrated into a composite Healthspan Index, these improvements revealed that TRF prolonged healthspan in females more effectively than in males. Only 8h-TRF extended lifespan in males by 12%, suggesting that TRF exerts sex-specific effects on aging.