Aside from making your mind less sharp and generally making you feel crappy, a new study demonstrates another unsavory effect of sleep deprivation: It could actually spur junk food cravings, similar to those induced by marijuana.
The study, published in the journal SLEEP, found that subjects who were sleep-deprived were more likely to consume junk foods offered to them, even when they had recently consumed meals that offered 90 percent of their necessary caloric intake. This effect was the strongest in the late afternoon and early evening—times when snacking is associated with weight gain. Those who were sleep-deprived consumed twice as much fat after 12:30 P.M. as those who had slept for eight hours, and they reported more hunger and a stronger desire to eat.
To figure out why sleep-deprived subjects were eating more, the authors also measured participants' blood levels of endocannabinoids—chemicals known to enhance the desire for food intake that are also found in the bloodstream after marijuana consumption. Levels for subjects who slept normally were low in the morning, peaked right after lunchtime, and then subsided. Endocannabinoid levels of sleep-deprived people, however, were about a third higher in the morning, peaked an hour and a half later, and stayed high (no pun intended) throughout the afternoon and evening.
"If you have a Snickers bar, and you've had enough sleep, you can control your natural response," Erin Hanlon, one of the study's authors, said in a press release. "But if you're sleep deprived, your hedonic drive for certain foods gets stronger, and your ability to resist them may be impaired. So you are more likely to eat it."
There's yet another reason to make sure you get those zzz's.
