The effects of HMB supplementation during 8 weeks of time-restricted feeding were studied in young, resistance-trained women. Time-restricted feeding is a type of intermittent fasting, where all daily calories are consumed during a smaller “feeding window” each day. Each study participant was assigned to either time-restricted feeding (TRF, 8 hours) or the control group (no feeding time restrictions). Half of the women in the TRF group took three 1g doses of HMB per day (upon waking, mid-morning, and at bedtime), while all other participants took placebo supplements on the same schedule.  All of the women completed the same whole-body resistance training program. 24 women completed the entire study as designed. In these women, fat free mass and muscle thickness increased in all three groups. However, only the TRF+HMB group significantly reduced fat mass (-7%) and significantly improved their body composition (-2.3 % body fat, an 8% improvement). These data show that HMB can help reduce body fat while maintaining muscle mass during intermittent fasting in active women.