Do you have cravings for potato chips or cookies at the end of a hectic day?
If the answer is yes… it may be from sleep-deprivation! According to a new study, researchers have found that the lack of sleep may lead to an increased appetite, and a deep desire for junk food.
Study author Erin Hanlon, a research associate at the University of Chicago, has said that “evidence from laboratory and epidemiological studies has started to consistently associate insufficient sleep with an increased risk of obesity.” Sleep loss has also been linked to decreased glucose tolerance,a risk factor for obesity. Depriving normal subjects of sleep has been shown to result in insulin responses to hyperglycemia characteristic of insulin resistance and a prediabetic metabolic state.
Mounting evidence from lab studies with animals and humans suggests a link between lack of sleep and increasing body weight. For example, prolonged sleep deprivation has been shown to increase food intake in rats. A study conducted by researchers at the University of Chicago found that short-term sleep curtailment impacted the neuroendocrine control of appetite in healthy young lean men. The subjects were found to particularly crave sweets, starch, and salty snacks after being deprived of sleep.
Hanlon’s study, published in the March, 2016 journal, Sleep, compared 14 otherwise healthy young adults who had four nights of normal sleep (8.5 hours) with those with four nights of restricted sleep (4.5 hours). Both groups were provided with carefully prepared meals. On the final day, participants were given a healthy meal, followed by free rein at a snack bar containing tasty treats including cookies, candy and chips (what researchers dubbed “highly palatable, rewarding snacks”). Those in the sleep-deprived group tended to eat snacks with more carbohydrates and nearly twice as much fat and protein.
The team’s previous research suggested that sleep deprivation affected levels of endocannabinoids, chemicals in the brain that are involved in regulating appetite and bind to the same receptors as marijuana.
Hanlon’s team, from the University of Chicago, Universite Libre de Bruxelles and Medical College of Wisconsin, was able to measure the concentration of a specific endocannabinoid called 2AG in the blood. For both groups, the researchers matched those levels with hunger and food intake.
Under normal sleep conditions, the concentration of 2AG gradually increased in the blood during the day, reaching a peak in the early afternoon that coincided with the onset of early afternoon munchies. But for subjects who had less sleep, not only did researchers note greater increases in 2AG concentration that lasted into the late evening, but participants were also hungrier and more likely to eat unhealthy snacks. “The increase in endocannabinoid concentration occurred at the same time people reported feeling hungrier,” Hanlon said. “It was definitely surprising to see an increase.”
Although the study is small, Hanlon’s team ran statistical tests on the data which showed that there were, in fact, significant differences between the two groups. Hanlon stated “this study is an important step in understanding the relationship between the endocannabinoid system, sleep deprivation and weight gain.”