Have you ever found yourself indulging in extra junk food when you’re sleep deprived? It turns out there may be a biochemical reason we crave more unhealthy foods when we haven’t been getting enough sleep.
In a study recently published in the journal Sleep, researchers at the University of Chicago found that volunteers had higher levels of the 2-AG brain chemical for longer when they were sleep deprived than they did when they were well-rested. 2-AG is what’s known as an endocannabinoid—it acts on the same parts of the brain as marijuana, including the parts associated with pain, pleasure, and appetite.
The 2-AG chemical is produced naturally in the brain, and its levels typically rise slowly throughout the first part of the day and peak in the early afternoon. However, when volunteers in the study were sleep deprived, their 2-AG levels peaked higher and stayed elevated longer into the afternoon and evening.
How Did Researchers Find a Link Between Sleep Deprivation and Overeating?
The researchers conducted this study by recruiting 14 young, healthy volunteers who reported that they normally slept about eight hours a night on average. These volunteers then participated in two separate four-day sessions at the University of Chicago sleep center. In one session, they were allowed to sleep up to eight and a half hours per night, and in the other session, they were allowed to sleep just four and a half hours per night. Researchers took blood samples during both sessions in order to measure changes in 2-AG levels.
In addition to tracking 2-AG levels, researchers also looked at the volunteers’ eating choices. On the fourth day of each session, volunteers had to wait until 3pm to eat, but at that point, they were allowed to eat as much of their favorite foods as they wanted from a buffet. Participants overate in both sessions, but overate by about 400 calories more when they were sleep deprived—and also tended to eat more of the unhealthier snacks, such as chips and candy. The increase in snacking corresponded with a higher level of 2-AG.
The results of this study fit with previous brain-imaging studies of sleep-deprived people, which have shown that the brain areas associated with reward become more active when the tired participants were presented with pictures of food.
CDC Sleep Facts
Image Source: http://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html
Erin Hanlon, one of the research associates involved in the study, hopes that the findings will bring greater awareness to the need for adequate sleep as part of an overall healthy lifestyle. Currently, the CDC estimates that a third of Americans regularly fail to get enough sleep. Adults ages 18-60 should ideally get at least 7 hours of sleep every night.
