Acute sleep loss in humans leads to a gain in fat mass and loss of muscle mass due to a disrupted circadian clock that dysregulates metabolism in adipose tissue and decreases structural proteins in skeletal muscle.

This study specifically showed that acute sleep loss (an all-nighter) is associated with a decrease in glucose metabolism in skeletal muscle, whereas this pathway is increased in adipose tissue. These data support other data suggesting that sleep loss may lead to a catabolic state in skeletal muscle.

While this study studied the effects of 24 hours of sleep deprivation, other studies have suggested that sleep quality and quantity are also important for metabolic health.