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Does Your Body Burn Calories While You Sleep?


*Nothing in this article constitutes medical advice. Seek the guidance of a physician if you have any questions.*

Virtually everyone in the world has been impacted by the pandemic caused by the novel coronavirus, COVID-19. Terms such as "social distancing," "wearing masks," and "quarantine" has become part of our everyday language. However, another term has been making headlines for months, and it is the "quarantine 15". According to Psychology Today, "you eat during self-quarantine and sheltering in place during the COVID-19 pandemic can help you cope better or make your stress worse". Many call the 15-pound weight gain in isolation the "quarantine 15." One devastating problem that has emerged in the past year is that Covid-19 is harder on people who are obese. According to Web MD, a new government report found that more than 40% of people living in the United States are obese. There is a significant percentage of folks who are morbidly obese. The CDC has dedicated a whole section on their website that discusses how obesity and Covid-19 have negatively impacted different ethnic groups. Although most people acknowledge "the quarantine-15", there is a growing community of folks taking steps to improve their overall health by shedding unwanted pounds. One pound of fat is equal to 3,500 calories, which means if a person reduces their caloric intake by 500 calories a day, they can lose a pound a week. With that being said, it is not hard to figure out why people are searching Google to find out whether one can burn calories while asleep.

Burning Calories While Sleeping: Myth or Fact?

One interesting fact about the human body is that it burns calories while sleeping to sustain life and regulate essential body functions. It is not a myth! As long a person is breathing, they will burn calories, which is how the body refuels itself. At this point, you are probably wondering how many calories a person can burn while sleeping. This number of calories burned depends on several factors, starting with the metabolism. Metabolism is formally defined as "the bodily processes needed to maintain life." Experts have a formula that helps determine how many calories a person burns at night while asleep (approximately). The basal metabolic rate (BMR) represents the number of calories burned when at rest, including sitting and sleeping. The first step in finding out how many calories are burned while sleeping starts with figuring out the BMR. The next step involves using the BMR in another equation. It is pretty simple after determining the BMR.

Determining the Basal Metabolic Rate (BMR)

To calculate BMR: The equation uses factors like sex, weight, and age, using inches for height and pounds for weight. It is important to note that the BMR computing from the following equation represents the number of calories burned daily from doing nothing. 

  • 66 + (6.2 x weight) + (12.7 x height) – (6.76 x age) = BMR for men
  • 1 + (4.35 x weight) + (4.7 x height) – (4.7 x age) = BMR for women
  • For example: A 45-year-old man who weighs 225 pounds and is 5 feet 11 inches tall would be: 66 + (6.2 x 225) + (12.7 x 71) – (6.76 x 45) = 2,059 calories.
  • A 35-year-old woman who weighs 175 pounds and is 5 feet, 5 inches tall would be: 655.1 + (4.35 x 175) + (4.7 x 65) – (4.7 x 35) = 1,555 calories.

The heavier the body mass, the more calories burned while sleeping, resting, or doing other activities. Therefore, men typically burn more calories at rest than women, even if they are of the same height and weight. Why? Because muscles burn more calories than fat, which is why every person's BMR is unique to them.

Calculating Calories Burned While Sleeping

So, let's get to the "good" part, finding out how many calories are burned while sleeping. So, we have established that the body will burn calories throughout the night to support its metabolic processes. But, because the body is physically inactive, the metabolic rate is around 15% lower when a person is asleep than when they are awake. To get a reasonable estimate of how many calories the body burns while sleeping, a person needs to find their hourly BMR and multiply that by the number of hours they sleep before reducing the figure by 15%.

The following formula determines the "approximate" calories burned while asleep:

  • Calories burned while sleeping = (BMR / 24) x number of hours asleep x 0.85
  • The 45-year-old male weighs 225 lbs. 5 ft 11 will burn approximately 583 calories during an 8-hour sleep.
  • The 35-year-old female weighs 175 lbs. 5 ft 5 will burn approximately 441 calories during an 8-hour sleep.

Factors that Influence A Person's BMR

Several variables can influence a person's BMR. These factors include:

  • age
  • gender
  • ethnicity and race
  • height and weight
  • hormone levels
  • muscle-to-fat ratio
  • physical activity levels
  • diet
  • amount and quality of sleep
  • pregnancy and lactation
  • general health
  • health conditions that affect the metabolism, such as hypothyroidism and hyperthyroidism

Burning Calories and Getting Enough Sleep

Scholars have found that humans burn most calories during the deep rapid eye movement (REM) part of sleep. The brain is most active during REM because it requires the most oxygen to function. Humans cycle through several sleep cycles bout every 90 minutes, which occurs several times throughout the night. The metabolic activity also goes through cycles throughout the night. Most people underestimate the power of sleep and what it does to rejuvenate the mind and body. Good quality sleep is crucial to reaching optimal health because even though the body is physically inactive, many different processes are going on during sleep. During these tumultuous times with a looming pandemic, everyone must get adequate sleep and exercise to shed unwanted pounds. Sleep deprivation can cause a weakened immune system and weight gain, leading to other health problems.



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