For a 2011 study in The Annals of Internal Medicine, researchers had 10 overweight, middle-aged participants go on a moderate diet. For two weeks, half of the participants slept for eight and a half hours per night. The other half only got to sleep for five and a half hours. Both groups lost the same amount of weight—three pounds (1.4 kilograms) on average—but those who got more sleep lost more in the form of fat. Those who got less sleep also showed higher levels of ghrelin, a hunger hormone. Increased ghrelin can make you hungrier, boost fat retention, and reduce calorie burn. Weirder still, a 2016 study in the journal Sleep found that sleep deprivation can increase the peaks of a chemical known as an endocannabinoid. If that word looks familiar, it's because it's related to the word cannabis. Endocannabinoids act on the same parts of the brain that marijuana does (ever heard of the munchies?). The study found that lack of sleep affects the daily rhythm of an endocannabinoid called 2-AG, which "may increase the hedonic aspect of food intake," study author Erin Hanlon told NPR. That is to say, it makes eating more pleasurable. That may be great news for your mouth, but bad news for your waistline. Learn more about the effects of sleep deprivation in the videos below.
Lack Of Sleep Really Does Make You Eat More
Late nights and early mornings can make even those with the strongest willpower give in to temptation and head for the drive-thru. But being short on time might not be the only reason you eat badly during busy weeks. According to research, lack of sleep is actually telling your body to eat more.
The Science Of Appetite
Learn about how hunger hormones affect how much you eat.
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Why Do We Sleep?
Hear about the other things sleep does for you.
from Brain Stuff
How Sleep Affects Your Microbiome
The bacteria in your gut have a big effect on your health. See what sleep does for them.