This Causes Bad Food Choices When Sleep-Deprived, New Study Finds
Ever reach for a pillowy doughnut in lieu of an actual pillow when you're sleep-deprived? You're not alone. Beyond messing with our mood and productivity, lack of sleep can make us crave processed foods high in sugar, salt, and fat. New research out of Northwestern University digs into why we gravitate toward unhealthy treats when we're tired—and offers up a quick trick for breaking the habit.
Snacking while sleepy has a lot to do with your nose.
It turns out, the smell of those high-calorie treats is what's so appealing to our sleep-deprived brains.
According to the study, your sense of smell is heightened after a bad night's rest, so that sweet treat might smell extra tempting. At the same time, the connection between areas of the brain that dictate food choices appears to break down. When we get enough sleep, the piriform cortex (the part of the brain that perceives smells) is in dialogue with the insular cortex, which helps regulate food intake by keeping track of things like how much food is already in the stomach.
The study suggests that communication between these cortices gets muddled with lack of sleep, which throws off our endocannabinoid system—an important system of the body that regulates most physiological processes. Researchers believe that an increase in one endocannabinoid in particular, the 2-OG compound, is what causes us to reach for smell-good treats when we're sleepy, nutrition be damned.
They came to this conclusion by way of a two-part experiment on 29 men and women, ages 18 to 40. The small group of participants was divided in half. One group got a normal night's sleep while the other was only allowed to sleep for four hours, and then they switched a few weeks later. Both groups were given access to a menu of various breakfast, lunch, dinner, and snack options the day after their sleep was monitored.
"We found participants changed their food choices," Thorsten Kahnt, a senior author on the study, writes. "After being sleep deprived, they ate food with higher energy density (more calories per gram) like doughnuts, chocolate chip cookies and potato chips." Highly processed foods like these are known to end in a blood sugar crash—exactly what you don't want when you're already running low on sleep.
Moral of the study: Try avoiding the smell of unhealthy food after a bad night's sleep.
The next time you're sleep-deprived, be mindful of what you're smelling, and see if it helps you make healthier food choices. In the study, Kahnt gives the example of detouring to avoid walking by your local doughnut shop. You could also steer clear of the pastry section of the supermarket or avoid the part of the office that smells like fresh-baked cookies. It also may be worth it to try surrounding yourself with healthy snacks that are also high in calories and therefore might smell extra good to your brain, like nuts and seeds.
Indulging in a treat when you're tired obviously isn't the end of the world, but if you don't want to make it a habit, this trick could prove particularly on the nose.
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