The Connection Between Sleep and Obesity

Medically Reviewed by Nayana Ambardekar, MD on April 11, 2024
4 min read

When you don’t get enough sleep, it does more than make you tired. Too few ZZZs can also lead to weight issues, which can bring all kinds of medical conditions.

At the same time, being overweight or obese is linked to a higher risk for sleep disorders, including:

It's not clear whether that's because sleep loss leads to weight gain or because the physical and metabolic effects of obesity keep you from sleeping soundly.

But studies have shown that losing weight can help you sleep better. And getting enough sleep may help make your weight loss plan more effective, as well as improve your overall health.

There are several ways that too little sleep can change how much you weigh.

Appetite changes. Two hormones in your body help control your appetite. Leptin tells your body when you’re full. Ghrelin, on the other hand, helps tell your brain that you’re hungry. Like some other hormones, how you get them is related to your sleep/wake cycle, also known as the circadian cycle.

When you don’t get enough sleep, your levels of leptin go down. So your brain sends out signals that you’re hungry, even though you don’t need to eat. At the same time, your levels of ghrelin go up, so you feel hungry.

When you feel those hunger pangs, you’re more likely to grab food that’s high in fat and calories instead of something healthy. To keep yourself from binging, limit the amount of junk food in your house. That way, you'll reach for healthy snacks more often. You can also drink a glass of water to see if that fills you up instead. Sometimes when you're hungry, you're actually thirsty.

More snacking. It makes sense that the longer you're awake, the more time you have to eat. This can lead to something called the “fourth meal.” But even if you’re not going that far, more snacking throughout the day adds extra calories and can lead to weight gain.

Before you grab something to tide you over, ask yourself if you're truly hungry. If not, instead of eating, try to drink some water or go for a walk.

Less exercise. When you don't sleep enough, you’re less likely to exercise because you’re too tired to go for a walk or head to the gym.

Though it might be hard to get going, try to get off the couch and start moving. Not only will regular exercise help you lose weight, but it can also make it easier for you to sleep. If you normally have troubling sleeping, don't exercise within a few hours of bedtime. Your workout might rev you up and make it harder to get the rest you need.

Just like adults, kids who don’t sleep enough can also have weight problems. Proper rest is just as important as nutrition and exercise to your child’s health. And good sleep habits should start early.

Infants who sleep less than 12 hours a day are twice as likely to be obese by age 3 than those who sleep more than that. If a 3-year-old sleeps less than 10 1/2 hours each night, there’s almost double the chance they will be obese by age 7.

To help kids sleep, set a calming routine that starts about 30 minutes before bedtime. It should include quiet activities like reading or listening to music. Stick to regular bedtimes. Keep phones, computers, and TVs out of the bedroom, too.

Sometimes, extra weight can make it harder to sleep comfortably.

Larger people may be more comfortable sleeping on their sides. When you sleep on your back, gravity's pressure on your body can make it harder to breathe. You're also less likely to snore when you sleep on your side. Use a pillow to prop yourself up if that feels good.

Make sure your mattress is firm enough to be supportive. Choose a pillow that keeps your head in line with your spine when you're in your usual sleeping position.

If you tend to get hot while you sleep, look for mattresses and bedding made of breathable, cooling materials. Use a fan, and keep your thermostat set at 60-68 degrees.