How Many Calories Do You Burn While You’re Asleep?

how many calories are burned sleeping

Are you wondering how many calories are burned while sleeping? 

It makes sense to dabble with this question since there aren’t many places where you will find the correct answer to it. 

When it comes to weight loss, most people obsess about the number of steps they walk, the total calories they consume, and they also want to be the first one to buy the latest fad diet book to replace that flab with muscle. 

Primarily, people are more concerned about burning fat while they are awake–during the day. This is what makes the topic of this post so intriguing. 

It is a well-known fact that a healthy human being spends a third of his/her life sleeping. That’s almost 25 years! When we lie on the bed at slumber time, we slip into the state of being asleep through several phases. 

The objective here is to attain a state of deep sleep. This is where the magic happens, and most people experience vivid dreams. Further, from the context of this post, it would also benefit you to learn about the two main sleep phases: NREM (non-rapid eye movement) and REM (rapid eye movement). 

What are the NREM and REM sleep phases? What does your body do while you are asleep?

A single sleep cycle consists of 1 REM phase followed by 4 NREM phases. A healthy adult goes through 5 such sleep cycles during a 7–8-hour sleep. With each sleep cycle, the duration of the REM phase tends to get longer. 

For the vast majority (70-75% of the time), a person while asleep is in the NREM phase. This is the phase when the growth hormones are released in the body. Hence, this phase is massively essential for good health.

Furthermore, researchers have also found a link between sleep and metabolism. Researchers at the Brody School of Medicine, Greenville, believe that the energy expenditure is reduced during sleep. It is reduced by 15% during the NREM phase. The amount of energy your body spends varies greatly depending on the sleep phase you are in. 

Hence, if you compare the calories burned during wakeful and sleep state, you will find a massive gap between both. When you are asleep, your body burns way fewer calories than it does otherwise.

An experiment was conducted by researcher Kenneth Wright from the University of Colorado to find the exact amount of calories burned during sleep. Dr. Wright and his team were aware of the fact that there is an expenditure of energy during sleep, and as a result, some calorie loss is expected. 

They took seven young people and asked each participant to sleep in a particular room for three days. 

The first night they were asked to sleep the way they usually would, and no readings were taken. The second night they were barred from sleeping at all and were only allowed to lie on the bed. Further, the third night they were asked to sleep normally. 

Between each reading, the participants were given a few days off. In conclusion, on the second night, they burned approximately 135 calories each, and on the third night, the count went to 160. 

When we sleep, our brain works tirelessly to improve our memory and also, in the due process, releases growth hormones into the body. Hence, the expenditure of extra-25 calories on the days the participants slept usually.

How many calories does a person burn while asleep? How to calculate it?

There is no method or a technique to calculate the exact amount of calories you burn while asleep, as it depends on several parameters. Parameters like the temperature of the room you sleep in, your diet during the day, your race, region, and culture massively impact the calories burned while sleeping. 

According to a study, African Americans tend to have a lower sleep metabolic rate compared to Caucasians. They are also more likely to gain weight due to imbalances in their sleeping patterns. 

Having said that, if you still wish to find out approximately how many calories you burned last night while sleeping, you can check out the “Calories Burned Calculator” from FitWatch

An average American male weighs around 200 pounds. So, just to find out the efficacy of this tool, we entered the weight (200 pounds), duration (480 minutes) in the calculator. The result was 686 calories burned. Quite impressive! 

Moreover, when the same person walks for 480 minutes, they burn a total of 3,048 calories. So, almost six times more than while sleeping. You will be surprised to hear that, when it comes to calories burned, there is a vast difference in just lying on the bed reading a book and being deep asleep. 

When you are in a state of a deep sleep, although the metabolic rate of your body lowers, the body still works hard to repair and revive the blood cells. Hence, there is some exertion of energy in certain phases of the sleep cycle.

Does eating before bedtime affect the calories burned while sleeping?

Your family doctor must have advised you not to eat before bedtime. Eating at night is also considered to be a bad habit in certain cultures. But is there any truth to these claims? 

Most people eat before bedtime as the sensation of food burning in their belly helps them fall asleep. It also ensures that they don’t get up in the middle of the night feeling hungry. Unfortunately, several studies conclude that eating before bedtime makes you gain more weight

But the good news is, there are a handful of researchers who deny these claims and believe that it is the overall calorie intake which dictates weight gain or loss. According to a report by the U.S. Department of Agriculture, it does not matter what time of the day you eat, when it comes to weight gain, what matters most is the overall calorie intake (throughout the day) and the amount of physical activity you do. They believe an active person can easily afford to have a couple of cookies before bedtime. 

These conflicting views have led to a lot of confusion. To ease the hodgepodge, we are sharing another study by Northwestern University that details experiments performed on rats to find out how eating before bedtime influences weight gain. 

In this experiment, they took two sets of mice; one set was fed a high-fat diet during regular sleeping hours, whereas the other was given the same food during their natural wakeful hours. 

Upon observation, the researchers found that the mice who were fed during the daytime (mice are nocturnal creatures; hence they usually eat at night) had a 48 percent weight increase over their baseline, whereas the other set had a mere 20 percent increase over their baseline.

I understand that a conclusion derived from an experiment performed on two groups of mice cannot hold for humans. But the results were astounding, and this experiment was performed to help out night-shift workers. Undoubtedly, the insights from this experiment must have helped them.

Conclusion

We hope this post helped you understand how sleep is linked with weight gain. For humans, sleep is as essential as food. This is the period when your body recovers from the damages incurred during the wakeful state and prepares itself for the day ahead. 

You lose more calories while asleep than you lose by merely lying on the bed. So, make sure you get 8-9 hours of sleep each night. In the comments below, let us know if you have any questions related to burning calories while sleeping.