It’s been known for years that lack of sleep can help you gain weight, but new research gives us an idea of why. Apparently, sleep deprivation gives you the munchies.
An experiment aimed at explaining why people overeat after a poor night’s sleep suggests that food becomes much more appealing, and that the brain’s own marijuana-like chemicals are responsible.
“Sleep restriction seems to augment the endocannabinoid system, the same system targeted by the active ingredient of marijuana, to enhance the desire for food intake,” said Erin Hanlon, a UChicago research associate in endocrinology, diabetes and metabolism.
Hanlon, working as partof a team that’s been studying sleep and eating habits, looked at a brain chemical called endocannabinoid 2-arachidonoylglycerol (2-AG for short). It resembles the same chemicals found in cannabis, but it’s made in the brain and affects pain, pleasure and appetite.
When the study subjects were sleep-deprived, endocannabinoid levels rose higher and remained elevated through the evening, beyond the typical 12:30 p.m. peak. During that period, sleep-restricted study subjects reported higher scores for hunger and a stronger desire to eat. When given access to snacks, they ate nearly twice as much fat as when they had slept for eight hours. Sleep-deprived participants in this study—all young, healthy volunteers—were unable to resist what the researchers called “highly palatable, rewarding snacks,” meaning cookies, candy and chips, even though they had consumed a meal that supplied 90 percent of their daily caloric needs two hours before.
Researchers say the additional appetite can’t be explained by the need for extra food simply because the subject was awake. They say that each additional hour awake really only requires about 17 calories.