Tallying the caloric cost of an all-nighter

The body conserves energy during sleep, more so after missing zzz's

Staying up all night clearly taxes the body, but scientists have only now added up the exact bill. By measuring the actual number of calories the body expends to fuel an all-nighter versus a good night’s sleep, researchers from the University of Colorado at Boulder calculate that a full night of sleep helps the body conserve as much energy as is in a glass of warm milk.