0519 GMT September 15, 2019
Skimping on sleep has long been associated with overeating and poor food choices.
Now researchers at the University of Chicago have found that sleep-deprived people craved crisps, sweets and biscuits far more than healthier foods.
The new study, published in the journal SLEEP, shows how sleep loss initiates this process, augmenting the same system targeted by the active ingredient of marijuana that enhances the joy of eating, particularly the guilty pleasures gained from sweet or salty, high-fat snack foods.
Young healthy volunteers undergoing sleep deprivation were unable to resist "highly palatable, rewarding snacks" such as biscuits, candy and crisps even when they had consumed 90 percent of their daily caloric needs.
“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 Dr. Erin Hanlon of the University of Chicago.
Researchers also observed that the effects of sleep loss on appetite were most powerful in the late afternoon and early evening, times when snacking has been linked to weight gain.
When sleep deprived the volunteers reported a significant increase in hunger levels and expressed greater desire to eat. Despite having eaten a large meal less than two hours before being offered snacks, subjects in the restricted sleep phase of the study had trouble limiting their snack consumption.
They chose foods that provided 50 percent more calories, including twice the amount of fat, as when they were completing the normal sleep phase.
This increase in levels of the chemical, called 2-AG, the authors note, “could be a mechanism by which recurrent sleep restriction results in excessive food intake, particularly in the form of snacks, despite minimal increases in energy need".
According to Harvard's Frank Scheer these results support “the novel insight that sleep restriction leads not only to increased caloric intake”, but also to “changes in the hedonic aspects of food consumption”.
“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. Do that again and again, and you pack on the pounds,” said Hanlon.