Researchers at the University of Arizona recently published a study that showed that individuals who were limited to five hours of sleep on weekdays gained more than three pounds over two weeks and had metabolic changes that would increase their risk for diabetes in the long term.
While weekend sleep recovery showed some benefits after a single week of insufficient sleep, those gains were wiped out when people resumed their same sleep-deprived schedule the next week. Most experts recommend at least seven hours of sleep per night.