The Connection Between Sleep and Obesity

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.

How It Happens

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 bingeing, 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.


Kids, Sleep, and Weight

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.

WebMD Medical Reference Reviewed by Brunilda Nazario, MD on March 17, 2020



Obesity Review: “The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review.”

PLOS Medicine: “Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index.”

National Sleep Foundation: “Does Sleeping Longer or Shorter Impact Your Weight?”

American Journal of Clinical Nutrition: “Short sleep duration increases energy intakes but does not change energy expenditure in normal-weight individuals.”

American Society for Nutrition: “Is Obesity Linked to Sleep Deprivation?”

Harvard Health Publishing: “Six healthy snacking strategies.”

Harvard School of Public Health: “Sleep Deprivation and Obesity.”

Medicine: “Assessment of sleep and obesity in adults and children.”

Pediatrics: “Thoughts on the Association Between Sleep and Obesity.”

Academy of Nutrition and Dietetics: “How Sleep Habits Affect Healthy Weight.”

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