The Science Behind Burning Calories While Sleeping

The Science Behind Burning Calories While Sleeping

Do we burn calories even when we are sleeping? If yes, How many calories do you burn sleeping?

Usually, our body burns around 55-60 calories while sleeping, but it also largely depends upon everybody’s Personal Basal Metabolic Rate (BMR). 

Sleeping time is a crucial time of the day as the body resorts to repair and regeneration. During sleep, the body temperature drops, breathing slows down, and the metabolism mechanism slows down too. Generally, the body burns about 15% fewer calories while sleeping than during daytime activities, when the basal metabolic rate is higher.

What is BMR? Does it Determine How Many Calories do you burn sleeping?

The basal metabolic rate is equal to the amount of energy in kcal that is needed by body function if it were to rest for 24 hours. It is the energy needed for vital functions like cellular growth and repair, breathing, temperature regulation, and circulation. One may ask, How many calories do you burn in a day? The BMR accounts for nearly 80% of the total calories burned in a day. The brain burns glucose too for energy, which makes up for about 20% of the calories we consume while at rest.

Factors that Affect the Basal Metabolic Rate

The basal metabolic rate differs for each person depending upon several factors, only some of which can be changed:

● Height & Weight: A person with good height and weight needs more energy to function.

● Fitness: Our muscles burn more calories than fat, so fit people actively burn more calories, even when resting.

● Gender: Men have higher BMR than women, always because they tend to have a higher activity of repair and regeneration.

● Age: Children also have a higher metabolism, but Metabolism decreases as we age.

● Diet: Not eating enough nutrients and a balanced diet food or overeating junk can be a reason for lousy functioning Metabolism.

● Sleep Quality: Poor sleep quality and insufficient sleep also cause Metabolism to slow down.

● Genetics: Genetics may also have a more significant hand in influencing Metabolism to some extent.

● Hormones and Medical Conditions: Menopause, hypothyroidism or hyperthyroidism, Lactation, Pregnancy can fluctuate the BMR. 

Calculate How Many Calories Do You Burn While Sleeping

Understanding how many calories do you burn while sleeping is achieved by calculating the BMR. However, Accurate BMR calculation requires specific equipment that determines precisely how much oxygen a person is breathing, inhaling, and exhaling over a certain period.

But using the Harris-Benedict equation, it is possible to get the nearly accurate BMR:

This equation takes a person’s sex, age, weight, and height into account.

Females, the formula is:

BMR = 665.1 + (4.34 x weight (pounds)) + (4.7 x height (inches)) – (4.68 x age (years))

Example :

BMR of 26 year female, height – 5’3 and weight- 165

BMR = 665.1 + (4.34 x 165) + (4.7 x 63) – (4.68 x 26) = 1522.8 kcal/day.

Males, the formula is:

BMR = 66.47 + (6.24 x weight (pounds)) + (12.71 x height (inches)) – (6.78 x age (years))

Example :

BMR of 26 years Male, height – 5’7 and weight- 170

BMR = 66.47 + (6.24 x170) + (12.71 x 67) – (6.78 x26)= 1790kcal/day

The formula will give the count of how many calories do you burn in a day due to BMR alone.

Factors that affect how many Calories Burned Sleeping

  • Exercise daily and strength training help you burn more calories, even while you’re sleeping.
  • Losing weight may help because calories burned sleeping by fat is lower than muscle.
  • Caffeine may create a short-term boost. It may increase Metabolism slightly.

Calculating How many calories do you burn while sleeping

The body continues burning calories throughout the night, but since the body is physically inactive, the basal metabolic rate is around 15% lower during sleeping than when it is wide-awake.

To determine how many calories the body burns while sleeping, one needs to calculate BMR hourly and multiply that by the no. of hours of sleep before reducing the figure by 15%.


Calories burned while sleeping = (BMR / 24) x number of hours asleep x 0.85.

Sleep Better to Burn Extra Calories

We have done the math, and we can tell that one can burn calories anywhere between 200 and 600 calories each night. To increase calorie burning, try sleeping in a cool, calm, and darkroom. Cold Temperature helps to burn more calories to maintain the body temperature.

You can burn the most calories during REM (rapid eye movement) sleep.

If you’re struggling to get those seven hours each night, maintain a regular sleep schedule and limit electronic and television use before bed. 

Healthy Sleeping Tips

Getting 7-8 hours of sleep daily is vital to a person’s physical and mental health. Although when you skip sleeping some night, you may lose more calories than usual. But not getting quality sleep can affect a person’s concentration, work performance, mood, and energy levels. According to the National Institute of Neurological Disorders and Stroke, research says insufficient sleep can cause risks to health, including:

  • heart disease
  • depression
  • high blood pressure
  • diabetes
  • obesity

The American Academy of Sleep Medicine and the Sleep Research Society suggest that people between the ages of 18 and 60 should at least get 6-7 hours of sleep every night

Tips to improve the quality of sleep include:

  • Avoiding reckless consumption of caffeine or alcohol just hours before bedtime
  • Having a fixed sleep routine
  • Regular exercise and strength training
  • waking up to natural light
  • Having relaxing rituals before bed, such as reading a book or taking a warm bath

Therefore, it’s crucial to know how many calories do you burn while sleeping. Sleep is crucial for burning calories but is also vital to maintaining good health and sound mental health. Maintaining an overall healthy lifestyle is also essential to losing calories and having a healthy functional basal metabolic rate (BMR).