"We have very substantial research that shows if you shorten or disturb sleep, you increase your appetite for high-calorie dense foods," says Charles Samuels, MD, medical director of the Centre for Sleep and Human Performance in Calgary, Alberta. "On a simplistic level, your appetite changes."
If you're chronically sleep-deprived and consume more high-calorie foods, it's likely those calories will be deposited around your middle, forming fat deposits that are especially dangerous for raising your risk of type II diabetes. "It's known as visceral fat deposition," says Dr. Samuels. "Sleep-deprived individuals' ability to respond to a glucose load and release insulin is altered."
Countering an occasional sleepless night with chocolate the next day won't set you back too far, but research suggests you may gain weight if sleep deprivation and overeating become routine. "Individuals who are obese tend to sleep less," says Orr. "There's been a marked increase in obesity over the last 10 years, and over the last 50 years, there's been a marked reduction in average sleep time for the average Americanwhich suggests a link between sleep, appetite regulation, and obesity."
"There are no guarantees that sleeping more will translate into pounds lost," says Orr. "But if you have chronic sleep deprivation or chronic fragmentation of sleep and you stop that habit or correct the problem so you sleep well, it will probably be easier to lose weight."
Rest. "Get the sleep you need, end of story," says Dr. Samuels. "People always want some magic answer beyond that, but you've got to get your sleep. My biggest issue is people who wake up at 4 to go to the gym. People should focus on sleep first, to get to their goal from the weight perspective."