A lot of things affect your metabolism—the chemical reactions in your body that change food into energy—from your age to your body size to your genetics to your level of physical activity.
According to a recent study published in the Journal of Lipid Research, your sleep habits play a big role in your metabolism too. In fact, the study reveals that just five nights of troubled sleep can slow down your metabolism, leading to unwanted weight gain.
Sleep and metabolism study
For the study, 15 men spent 10 nights at a sleep lab. For five of the nights, they were kept awake so they would get no more than five hours of sleep. After four of those sleep-deprived nights, they were given a late-night, high-calorie meal of chili mac and cheese. After testing their blood, the researchers discovered that their bodies weren’t clearing the fat as efficiently as they should, causing lipids to build up and fat to coat their arteries—something that could predispose people to put on weight.
The study authors note that while this particular study was limited (participants were all healthy males and the study was conducted in a highly controlled environment), it still provides valuable insight into how our bodies digest fat.
Here, learn more about how sleep affects your metabolism and how to improve your sleep to keep your metabolism in check.
How does sleep deprivation impact metabolism?
Sleep deprivation works quietly below the surface at the cellular level, affecting metabolic processes in ways you can’t see, says Alex Lewis, RD, a dietitian with Baze, a nutritional testing company.
Here’s what’s going on: When you don’t get enough sleep, your body ups its production of ghrelin, the hormone that stimulates appetite. Poor sleep also leads to a decrease in leptin, the hormone that suppresses appetite. An increase in ghrelin and a decrease in leptin can lead to more cravings (especially for junk food and carbs) and reduced feelings of fullness. Plus, when you’re sleep-deprived, you’re naturally awake for more hours, and that can provide you with more opportunities to eat, notes Lewis.
So how can you tell if you’re sleep-deprived—and if, in turn, you’re throwing your metabolism out of whack? It’s not so black and white. “There’s not necessarily a specific number of hours of sleep per night or days per week required before someone can be sleep-deprived,” says Lewis. “It’s a bit more subjective.” What is clear is that most adults should aim for seven to nine hours of sleep per night. (Take our sleep deprivation quiz to find out if you need more sleep.)
The good news is, occasionally skimping on sleep probably won’t have any major long-term effects on your metabolism, although it can mess with your ability to properly digest fat in the short term. “A few days with a little sleep is not going to be detrimental in the long run,” says Lewis, “but you still may notice effects on metabolism and total consumption of food each day.”
Related: Here’s what the keto diet does to your sleep
How can you improve your sleep and keep your metabolism in check?
It’s as simple as this: Better sleep means better metabolism. Luckily, there are a few easy things you can do to improve your sleep and optimize your metabolism.
Lewis shares these activities that you can include in your nighttime routine:
- As it gets dark outside, turn on nightshade mode on your phone or install a nighttime filter like f.lux. Curbing electronic use can help reduce the blue light that can have an impact on your body’s sleep hormones.
- Shut down electronics before bed, ideally doing so within an hour of going to bed. This may be difficult at first, so start somewhere—whether that’s 10 or 15 minutes initially and build up over time.
- Remove clutter from your bedroom and ideally use your bedroom for sleeping and romance only. Removing unnecessary items from your bedroom can provide mental clarity—racing thoughts are often a culprit to less-than-desirable sleep.
- Eating too close to bedtime can make it more difficult to have quality sleep—and can cause heartburn, night sweats, and blood sugar dysregulation. Aim to avoid eating within two to three hours of bedtime to give your body enough time to digest and utilize the foods you’re eating.
- Taking a hot shower or bath before bed can also be helpful. The hot temperature can actually help lower your core body temperature and prepare your body for sleep.
Hungry before bed? These healthy late-night snacks will help you fall (and stay) asleep.