Sleep Deprivation and Obesity
A growing body of research suggests that there's a link between how much people sleep and how much they weigh. In general, children and adults who get too little sleep tend to weigh more than those who get enough sleep.
For example, in the Nurses' Health Study, researchers followed roughly 60,000 women for 16 years, asking them about their weight, sleep habits, diet, and other aspects of their lifestyle. At the start of the study, all of the women were healthy, and none were obese; 16 years later, women who slept 5 hours or less per night had a 15 percent higher risk of becoming obese, compared to women who slept 7 hours per night; short sleepers also had 30 percent higher risk of gaining 30 pounds over the course of the study, compared to women who got 7 hours of sleep per night.
There are several possible ways that sleep deprivation could increase the chances of becoming obese. Sleep-deprived people may be too tired to exercise, decreasing the "calories burned" side of the weight-change equation. Or people who don't get enough sleep may take in more calories than those who do, simply because they are awake longer and have more opportunities to eat; lack of sleep also disrupts the balance of key hormones that control appetite, so sleep-deprived people may be hungrier than those who get enough rest each night.