Believe it or not, your body actually burns calories while you're asleep. Even though you're typically not moving in your sleep, your body is still expending energy. That's because your body needs a constant source of energy to maintain your metabolic processes and keep your body functioning.
Your body burns the most calories specifically during rapid eye movement (REM) sleep. According to experts who spoke to Insider, that's because REM sleep is the stage of sleep when your brain is most active. It's also when you burn the most glucose.
Not to mention, the amount of sleep you get every night can also affect the number of calories you burn. "There's a tremendous amount of evidence that shows that if you're not sleeping both from a quality and a quantity standpoint, you will gain weight," said sleep specialist Dr. Michael Breus (via Insider). However, sleeping too much can also slow down your metabolism and reduce the number of calories you burn.
How to calculate the number of calories you burn in your sleep
In order to find out an estimate of how many calories you burn while you're asleep, you'll need to first estimate your basal metabolic rate (BMR). Your BMR represents the number of calories you need to keep your body functional while resting. According to Eachnight, this number is based on a variety of different factors, including your weight, age, and gender. The easiest way to estimate your daily BMR is by entering this information into an online BMR calculator.
Once you've estimated your daily BMR, you can divide this number by 24 to get your hourly BMR and then multiply that by 0.85. That's because your body only functions at 85% when you're asleep. Then, you can multiply this by the number of hours you sleep each night. This will give you an estimate of the number of calories you burn in your sleep. For example, a 30-year-old woman who weighs 110 pounds will burn an average of 406 calories in her sleep, while a man of the same age who weighs 180 pounds will burn around 601 calories per night.
