If you’ve been gaining weight and not getting enough sleep lately, some new research suggests the problems are very likely connected. A study published in the European Journal of Clinical Nutrition reported that people who didn’t get enough sleep consumed an extra 385 calories the following day. A 2.5 ounce bag of potato chips or a banana nut muffin. can provide that many calories.
That’s enough extra calories to gain one pound every 9 days! While sleep deprivation has its own health consequences, the potential weight gain from consistently not sleeping enough is also a concern.
In this study, the researchers reviewed 11 other studies made up of 172 participants and compared people who didn’t get enough sleep (3.5 – 5 hours/night) to people who got adequate sleep (7 – 12 hours/night) and what the subjects in each group ate afterwards. What they found was that the sleep deprived people didn’t necessarily eat more, but they did choose foods higher in fat and lower in protein, with about the same amount of carbohydrate. The additional calories in the food choices of the sleep deprived people resulted in weight gain since they weren’t using those calories with increased physical activity.
The studies in this review were not designed to explain why people change their food choices following sleep deprivation, but the answer may lie in the reward center of the brain. The results of another study of sleep deprived adults showed greater activation in areas of the brain associated with reward when subjects were exposed to food. This suggests they would be more motivated to seek food when sleep deprived. Another study found higher levels of a lipid in the bloodstream known as endocannabinoid, a naturally produced compound that binds to the same receptors as the active ingredient in marijuana. Activating this part of the brain has been shown to make eating more pleasurable and result in a greater desire for palatable food.
Another proposed reason for the change in food choices by sleep-deprived people is a disruption in their hormones that control appetite, or the desire to eat. The natural circadian rhythms, or biological clock, of the body regulate our sleep-wake-feeding cycles to 24 hour periods. When those cycles are thrown out of sync by external influences, such as staying awake too long, other biological functions of the body are affected. Studies on sleep deprived people have shown they have reduced levels of leptin, a hormone that produces satiety, and increased levels of ghrelin, the hormone that regulates hunger. The change in these hormones in sleep deprived people supports their reports of having an increased appetite, even though they shouldn’t be hungry.
There’s one more twist to the sleep-weight gain story worth mentioning. When certain foods or beverages are eaten at night, they can interfere with the ability to fall asleep, or stay asleep. That can leave you feeling tired the next day. When you feel tired during your waking hours, you may turn to foods and beverages that will help you stay awake, such as those containing caffeine or high amounts of added sugars. This eating and drinking is not in response to hunger, but a way to temporarily become more alert. It not only introduces unneeded calories, but can create a vicious cycle of being overstimulated during the day, and unable to sleep well at night.
While there are still a number of unanswered questions, the evidence is growing that sleep and weight gain are connected. Fortunately, the solution for many people may be as simple as pulling down the shades, powering off all screens and turning out the light for a good night’s sleep so you can wake up ready to start the day with your appetite under control.
Robyn Flipse, MS, MA, RDN is a registered dietitian, cultural anthropologist and scientific advisor to the Calorie Control Council, whose 30+ year career includes maintaining a busy nutrition counseling practice, teaching food and nutrition courses at the university level, and authoring 2 popular diet books and numerous articles and blogs on health and fitness. Her ability to make sense out of confusing and sometimes controversial nutrition news has made her a frequent guest on major media outlets, including CNBC, FOX News and USA Today. Her passion is communicating practical nutrition information that empowers people to make the best food decisions they can in their everyday diets. Reach her on Twitter @EverydayRD and check out her blog The Everyday RD.