Two weeks of early time-restricted feeding (eTRF) improves skeletal muscle insulin and anabolic sensitivity in healthy men.

Plain-language summary

This study set out to see whether two weeks of eating earlier in the day improves how muscle takes up sugar and amino acids. Sixteen healthy young men were put into two groups of eight, one eating inside an early window and one on a control diet deliberately matched to it for calories and for weight lost, with muscle response measured before and after. The early eating group improved whole-body insulin sensitivity and their muscle took up more glucose and more branched-chain amino acids, the building blocks used for muscle repair. Because the comparison diet produced the same weight loss, the benefit is not explained by losing more weight. Two other studies in this library test the same idea of early time-restricted eating in different men, run by unrelated research groups, so the three are independent of each other.

Key findings

• Early time-restricted eating improved whole-body insulin sensitivity more than a control diet matched for calories and for weight loss.
• Muscle took up more glucose under early eating.
• Muscle took up more branched-chain amino acids, the building blocks used for repair.
• Both groups lost a similar small amount of weight by design, so weight loss does not explain the difference.