Effects of post-caloric restriction weight maintenance period on skeletal muscle and adipose tissue mass in male mice

Athletes often use caloric restriction (CR) to manage body weight.However, the effects of post-CR weight maintenance on skeletal muscle and fat mass remain unclear.This study investigated the effects of 60% CR for either 8 (8CR) or 2 (2CR) weeks on skeletal muscle and adipose tissue in mice.In the 8CR group, weight loss slowed after 2 weeks.However, body weight and wet skeletal muscle weight were significantly higher and inguinal white adipose tissue weight was significantly lower in the 2CR group compared with the 8CR group.These findings suggest that 8 weeks of CR, including a weight maintenance phase after initial weight loss, may result in a greater loss of skeletal muscle mass and an increase in fat mass compared to 2 weeks of CR.As this study was performed in 8-week-old male mice, the differences between the 2CR and 8CR groups are likely to reflect not simply the length of CR but rather the influence of conducting CR at different stages of growth.