By Victoria Shanta Retelny, RDN, LDN
Tired and hungry? Your sleep debt may be contributing to your junk food cravings.
Sleep is more than just a time to rest your eyes; it’s vital to your overall health and wellness—even your waistline.
Studies have shown that being sleep-starved can lead to overeating. A recent University of Chicago study, published in the journal SLEEP, examined the effects of sleep restriction on hedonic eating (eating not precipitated by energy need) in 14 healthy individuals ages 18 to 30 with regular sleep patterns. The participants were studied under two conditions: with 8.5 hours of sleep for four nights and 4.5 hours of sleep for four nights.
“The breadth of research on sleep restriction shows that hunger and appetite increase with sleep restriction,” says Erin Hanlon, PhD, first author of the study and research associate at the Sleep, Metabolism and Health Center at University of Chicago Medicine.
Over the course of the study, the sleep-deprived participants showed greater desire to eat. When they slept less, they ate more calories and fat in snacks—nearly 1,000 calories and twice the fat—in the early evening compared to only 600 calories in snacks when they had a full night’s sleep. “There was an inability to inhibit snacking when the participants were sleep-deprived. They were not only hungry, but they also snacked on high-calorie foods,” Hanlon says.
Lack of sleep stimulates the endocannabinoid (eCB) system, which is involved in appetite, mood and memory—the same system targeted by marijuana. Mindless munchies can ensue.
Researchers found that average levels of endocannabinoid 2-AG were the same in the two conditions over a 24-hour period, but there was a higher peak later in the day following the sleep-restricted condition. When they were sleep-deprived, participants reported later increases in hunger and appetite and were less able to stop snacking. “The peak in 2-AG led to an increased desire to eat midafternoon—after 2:30 p.m.—when participants were sleep deprived,” Hanlon says. Levels remained elevated until about 9 p.m., leading to later and larger snacks.
How important is sleep?
The quality of your sleep is just as important as a healthy diet and exercise in the prevention of chronic diseases, such as obesity, type 2 diabetes and heart disease, as well as premature death. The Centers for Disease Control and Prevention has termed chronic sleep insufficiency as a public health problem in the United States.
“Sleep is far from unproductive time,” explains Katherine Finn Davis, PhD, RN, CPNP, a nurse researcher at The Children’s Hospital of Philadelphia, who copresented a session about the importance of sleep at the Academy of Nutrition and Dietetics Food and Nutrition Conference & Expo (FNCE) held in Nashville.
“Sleep is vital for cognitive function, consolidation of memories, [and] optimal learning and is a neurobiological need among many other things,” Davis says. Yet, the National Center for Health Statistics reports that 30 percent of American adults do not meet the recommendation of getting at least seven hours of sleep daily.
There are many reasons we lose sleep, including work, family care, extracurricular activities, social activities, television viewing, early school start times and medical problems. “Even sharing your bed with someone else or a pet can affect the quality of your sleep,” says Devon Golem, PhD, RD, LD, copresenter of the FNCE sleep session and director of the dietetics program at New Mexico State University.
Whatever the reasons, sleep deprivation—whether acute or chronic—is risky. It can adversely affect cognitive functioning and the brain the same way that drinking too much alcohol can. (Research shows that after 19 hours without sleep, performance on some tests was equivalent to performance with a blood alcohol content of 0.05%, and 24 hours without sleep had the equivalence of 0.10%, which is legal drunkenness.)
Here are three ways to get better sleep and more of it:
1. Lights out. Dim lights at least an hour before bed. The sleep hormone, melatonin, comes out in the dark and allows you to sleep better.
2. Minimize media use before bed. Turn off laptops, smart phones and TVs to calm yourself down mentally and physically before you close your eyes.
3. Cut back on caffeine. Avoid stimulants with caffeine, such as soft drinks, energy drinks, coffee and tea, at least a few hours before bed.
Victoria Shanta Retelny, RDN, is a lifestyle nutritionist and author of Total Body Diet for Dummies. Follow her @vsrnutrition.