5 Ways Not Sleeping Enough Hurts Your Metabolic Health

Sleeping well is the cornerstone of good health. You think better and your mood and energy are elevated after a good night's rest. But things go haywire pretty quickly when you're not getting enough sleep—including your metabolic health. 

That's right. Sleep plays a sneakily important role in how your body uses and stores energy. Studies show that people who consistently fall short of sleep are at an increased risk of many cardiometabolic concerns1 like weight gain2, obesity, Type 2 diabetes3, and heart disease4. 

When sleep is compromised (even if it's just a night), it appears to make your cells less sensitive to insulin5. 

Insulin is the hormone that helps move blood sugar (glucose) out of the bloodstream and into cells for energy or to the liver to be stored for later. When cells don't respond—or become resistant6—to insulin, glucose levels remain elevated in the blood longer than they should be. 

So, say you always eat an apple in the morning. A bad night's rest could cause this food to spike your blood sugar, whereas you may have a more even-keel rise and fall in glucose levels after sleeping well. 

Over time this impaired blood sugar control may lead to consistently elevated blood glucose—a risk factor for diabetes.

Not sleeping well directly messes with your hunger hormones: leptin and ghrelin. Specifically, inadequate sleep decreases leptin9, the hormone that signals to the brain that you're full. At the same time, ghrelin levels (the hormone that stimulates hunger) increase. 

This can prompt an increase in appetite and cravings that make maintaining a healthy weight more challenging. Studies show that people who sleep less are heavier snackers10 and opt for high-calorie foods, for example. They also eat less protein and fiber11 (two nutrients essential for metabolic health and satiety) than those who sleep seven to eight hours a night.

Sleep and stress share similar pathways in the body12. Not only can sleeping poorly stress you out, but stress can make it challenging to fall asleep and stay asleep. It's a vicious cycle that's disruptive to your health. 

Let's dig into why this happens: Cortisol is a hormone that's released when you're under stress. Under short bursts of stress, the hormone helps you feel alert and energized—but, like sleep, it follows a circadian rhythm. Cortisol levels naturally peak in the morning12 (to help get you out of bed) and drop to their lowest levels at night (right as melatonin levels increase to induce sleepiness). 

High insulin paired with high cortisol from sleep loss is a recipe for undesirable changes to body composition14—spurring midsection fat accumulation (aka belly fat). 

Exercise benefits your metabolic health15 in so many ways. It helps with blood sugar control and insulin sensitivity, increases your daily energy expenditure, builds lean muscle mass, improves blood pressure, and the list goes on. 

But if you're tired, exerting yourself physically may not sound enticing. Research shows that fatigued adults get less moderate to vigorous physical activity, take fewer steps16, and engage in more sedentary behaviors (like napping, lounging, or resting). 

The general recommendation is to sleep between seven and nine hours a night17 for optimal health. Numerous long-term studies show that short sleep duration—often considered five to six hours a night or less—is linked to worsened metabolic health, longevity18, and gut health19. Sleeping too much20 can impact health in similar ways. 

That said, everyone's ideal sleep range is different. Some people may feel rested after six to seven hours of sleep, whereas others require eight or nine (maybe even more) on a more regular basis. And women often need slightly more sleep than men21. So it's important to learn (and respect) how much sleep you need each night to feel your best. 

About 88% of U.S. adults are metabolically unhealthy, and 33%22 do not get the recommended seven to nine hours of sleep each night. So most of us have room for improvement.

If you have trouble losing weight, snacking too much, craving sugary foods, or stressing all the time, you should definitely take stock of how much you're sleeping and the quality of that sleep. Sleeping better will not only help improve your metabolic health, but improving your metabolic health will also help you sleep better.