The distribution of dietary protein intake in the daily diet influences skeletal muscle hypertrophy via the muscle clock

https://doi.org/10.1016/j.celrep.2021.109336

Explanation

This study investigates the timing of protein intake, which is generally known to contribute to muscle growth.

Under normal circumstances, the dietary distribution of protein is also skewed throughout the day, but the physiological significance and impact of better protein distribution on muscle mass is not known.

Here, using a two-meal-per-day feeding model, the study finds that protein intake during the early active phase promotes overload-induced muscle hypertrophy in a way that depends on the local muscle clock. Mice fed a diet supplemented with branched-chain amino acids (BCAAs) during the early active phase showed skeletal muscle hypertrophy, but no distribution-dependent effect was observed.

They also examined the relationship between the distribution of dietary protein and muscle function, such as skeletal muscle index and grip strength in humans, and found that higher muscle function was observed in subjects who received dietary protein at breakfast rather than at dinner.

These findings suggest that protein intake at breakfast may be suitable for maintaining skeletal muscle mass.