Effects of day-time feeding on murine skeletal muscle growth and synthesis

Muscle mass is controlled by the balance between muscle synthesis and degradation. Although nutrition is important for the maintenance of muscle mass and growth, the effects of feeding time have remained unclear. In the present study, we aimed to evaluate the effects of day- or night-time-restricted feeding on the muscle volume using muscle atrophy and hypertrophy mouse models. The day- and night-time-restricted feeding was conducted from zeitgeber time 2 (ZT2) to ZT10 and ZT14 to ZT22, respectively. In the unilateral immobilization-induced atrophy model, the decrease in immobilized muscle weight did not significantly change with the feeding time. However, the contralateral non-immobilized muscle weight was lower in the mice fed at day time (inactive phase) than in those fed at night time (active phase). In the overloading-induced hypertrophy model, muscle hypertrophy and protein synthesis were attenuated by day-time feeding. These results suggest that day-time feeding attenuated muscle growth via the inhibition of muscle synthesis. Feeding at an irregular time such as a late-night meal could be detrimental for muscle growth.