- Sleep loss causes changes to your metabolism, which can lead to unhealthy food choices.
- Catching up on sleep over the weekend won’t counter the negative effects of sleep loss and may make things worse.
- Creating healthy sleep habits can help boost your immune system, metabolism, and academic performance.
You know the drill. You’ve been up studying for hours—it’s 2 a.m.—and the cravings are hitting hard. Chances are you’re not reaching for an apple or noshing on carrot sticks and hummus to fuel up. More likely, you’re raiding the cupboards for things like chips and cookies.
It’s not a coincidence that we tend to make not-so-great food choices when we’re sleep-deprived. Recent studies have found that sleep and metabolism are closely linked, and that getting a good night’s sleep is key for keeping blood sugar levels in check—and managing food cravings.
“Sleep deprivation changes the neurohormones [chemical messengers in your brain] that influence food choice and metabolism,” says Dr. Roxanne Prichard, associate professor of psychology at the University of St. Thomas in St. Paul, Minnesota, whose research focuses on the sleep habits of students. Two hormones in particular, leptin and ghrelin, control hunger and energy levels. When you have limited sleep, these hormones become unbalanced, causing you to feel ravenous, particularly for foods that aren’t as nutritious.
“The combined effects of these neurohormone disturbances trick your body into thinking it needs [to eat more], and a few slices of pizza will do the trick,” says Dr. Prichard.
How does this work?
A 2019 study in Current Biology found that young adults who were sleep-deprived (they’d gotten less than five hours of sleep per night) ended up eating more after-dinner snacks and had higher weights than when they had started the study. Their insulin sensitivity also decreased, meaning their bodies were less able to regulate their blood sugar, a potential precursor to metabolic diseases like diabetes. A similar study found that adult males were hungrier for calorie-dense foods when they were sleep-deprived compared to when they’d had enough sleep (Annals of Internal Medicine, 2004).
Sleeping in on the weekends doesn’t help
Interestingly, the Current Biology study found that catching up on sleep over the weekend did not help counter the negative effects of weekday sleep deprivation on metabolism. In fact, it made things worse. Study participants who were allowed to sleep in two days per week had higher drops in insulin sensitivity than those who never caught up on sleep. They also ate more during the week (while sleep-deprived) after a weekend of sleeping in compared to how much they were eating when the study began.
In other words, if you sleep in on the weekends as an attempt to “repay” the sleep debt you’ve accumulated, your body may struggle even more with regulating your blood sugar and metabolism than if you continued to get poor sleep on the weekends.
“When I’m tired, my level of focus is shot,” says Lisa, a student in Appleton, Wisconsin. “I’m much more likely to zone out in class or put less effort into assignments. I’m also less enthused about what I’m doing in school, so my work turns out mediocre.”
What can you do about it?
Sleep might seem dispensable when you’re trying to juggle everything in your life, but regular and consistent sleep is your key to health and academic success, according to Dr. Prichard.
Juan, a senior from Menifee, California, offers some suggestions on how to make this work: “Finish your homework and studying as soon as you get home. Don’t cram until the last minute pulling all-nighters. Set a time when you will sleep so you can get the proper amount of sleep needed, and put down the phone once that time comes.”
With quality, consistent sleep, you’ll experience:
During sleep, your body produces cytokines, chemicals that help ﬁght infections. Sleep is also vital for tissue repair and regulation of growth hormones.
Sleep is an essential time for the body to release hormones that help regulate mood.
During sleep, the neurons used for concentration and learning get a break to repair themselves.
“Getting regular, sufficient sleep is the best investment a student can make in [their] academic career,” says Dr. Prichard.
Roxanne Prichard, PhD, associate professor of psychology, University of St. Thomas, St. Paul, Minnesota.
Avadhani, R., Fowler, K., Barbato, C., Thomas, S., et al. (2015). Glycemia and cognitive function in metabolic syndrome and coronary heart disease. American Journal of Medicine, 128(1), 46–55. Retrieved from https://doi.org/10.1016/j.amjmed.2014.08.025
Bakalar, N. (2018, February 12). High blood sugar levels tied to memory decline. New York Times. Retrieved from https://www.nytimes.com/2018/02/12/well/mind/high-blood-sugar-levels-tied-to-memory-decline.html
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Depner, C. M., Melanson, E. L., Eckel, R. H., Snell-Bergeon, J. K., et al. (2019). Ad libitum weekend recovery sleep fails to prevent metabolic dysregulation during a repeating pattern of insufficient sleep and weekend recovery sleep. Current Biology, 29(6), 957–967. doi: 10.1016/j.cub.2019.01.069
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Spiegel, K., Tasali, E., Penev, P., & Van Cauter, E. (2004). Brief communication: Sleep curtailment in healthy young men is associated with decreased leptin levels, elevated ghrelin levels, and increased hunger and appetite. Annals of Internal Medicine, 141(11), 846–850.