A rigorous clinical trial published in the New England Journal of Medicine has found that popular 16:8 intermittent fasting leads to significant muscle mass loss, even when combined with resistance training.

Study Details

The 12-month trial followed 500 adults who practiced 16:8 fasting while maintaining a structured exercise program. Compared to the control group eating the same calories spread across the day, fasters lost 3.2% more lean muscle mass.

Expert Reaction

Nutritionists are urging caution, noting that muscle loss accelerates aging and metabolic decline. They recommend protein-prioritized meals during eating windows if fasting is continued.