How Does Your Body Use Calories While You Sleep?

How Does Your Body Use Calories While You Sleep?

The term “burning calories” is most commonly associated with aerobic activity as well as tasks that require a lot of physical exertion. However, in order to burn calories, you do not necessarily need to be participating in strenuous activity. Even while you are sleeping, your body continues to use them up, so they are never stored. Find out more about the activities your body does and how your body burns calories while you are sleeping, as well as the specific ways in which it performs this.


When we sleep, our bodies undergo a plethora of functions, some of which include transporting blood, processing food, and activity in the brain. All of this demand a certain amount of energy. The only method to obtain this energy while sleeping is to burn off the calories that have been stored throughout the day. To answer the question, “how many calories do you burn in your sleep?” you need to take into account both the rate of your metabolism and your body weight.


A lot of folks are taken aback when they learn how many calories we can burn when we are sleeping. Even though sleeping uses a lot less energy than most of the things we do during the day, it is still a busy time for our brain and some other physical systems.


The precise number of calories that are burned when sleeping is determined by a complex dynamic that involves sleep, food, physical activity, and other factors. Gaining an awareness of the elements that govern metabolism may assist you in regaining control of your health, particularly if you are struggling to maintain a healthy weight or have low levels of energy.

What are calories?



What exactly are calories, why do our bodies require them, and would a greater understanding of calories enable us to keep a healthier weight all through the course of our lives?


The amount of energy that is provided by a meal or beverage is measured in calories. The number of calories included in various foods is typically mentioned on the packaging, and certain wearables, such as the most advanced fitness trackers, allow you to keep track of the number of calories you burn through various activities.

Some foods, such as those that are fatty, fried, or processed, tend to have a higher calorie content than others. Other kinds of food, such as fresh fruits and vegetables, are typically lower in calorie content than others. However, there are some healthful fruits and vegetables that can be high in calories, whereas foods that are low in calories but provide little nutritional value, such as diet soda, are not considered healthy.

The number of calories that we require on a daily basis is determined by a number of factors, including our ages, whether or not we are actively attempting to lose weight, our levels of activity, and a few more. Each of the three primary macronutrients that we consume, notably carbs, fats, and proteins, contains a certain number of calories.

We need to find a happy medium between the number of calories we take in and the number of calories we burn. When we consume more calories than our bodies need (referred to as a “calorie surplus”), our bodies will store the excess calories as fat. If we continue to consume more calories than we require, we will eventually develop obesity-related health problems.

On the other hand, if we consume fewer calories than our bodies need or if we burn more calories through physical exercise than we take in, we will see a gradual decrease in body fat over the course of some time (calorie deficit). On the other hand, in order to maintain your health and provide the energy your human body needs for day-to-day activities, it is essential to consume an adequate amount of calories.

Stages of sleep



When considering whether or not you are getting enough sleep, it is natural to concentrate on the total number of hours spent in bed. Even if the amount of time spent sleeping is undeniably crucial, it is not the only factor to take into account.

It is also very important to give some consideration to the quality of one’s sleep as well as to the question of whether or not the time spent resting is genuinely restorative. A truly high-quality night’s sleep depends on the individual being able to get through the whole sleep cycle, which consists of four distinct stages of sleep, in a consistent and repeatable manner.

Simply put, during the duration of the night, your complete sleep is made up of numerous rounds of the sleep cycle, which is divided into four discrete phases. These stages are REM (rapid eye movement), and NREM (non-rapid eye movement). A person passes through four or six cycles of sleep during the course of an average night. Although the time of each sleep cycle varies, on average, it takes roughly an hour and a half for one to complete.

A wide variety of factors, such as a person’s age, their previous sleeping habits, and the amount of alcohol they consume, can cause their sleep cycles to differ from night to night and from person to person.

Understanding the Sleep Cycle

The very first stage of sleep is known as rapid eye movement (REM), and three other stages combine to constitute non-rapid eye movement (NREM) sleep. An examination of the brain’s activity when a person is sleeping reveals specific patterns that are characteristic of each stage, and this examination is used to define the stages of sleep.

The first stage, known colloquially as the “dozing off” stage, often lasts anywhere from one to five minutes on average.

Stage 1: Although the body and brain processes begin to slow down during N1 sleep, the body has not yet reached a state of complete relaxation. There are brief outbreaks of movement during this stage (twitches you may be calling them). During this stage, there are some subtle changes in the activity level of the brain linked with falling asleep.

Stage 2:
The body enters a more subdued state during stage 2, which is characterized by a drop in temperature, relaxed muscles, and a slowdown in both the breathing rate and the heart rate. Stage 2 also includes the onset of muscle relaxation. At the same time, there is a change in the pattern that the brain waves show, and the eye movement stops. The overall level of brain activity decreases, but there are still brief periods of activity that are necessary for maintaining resistance to being awakened by triggers from the outside world.

The time spent in Stage 2 sleep during the first sleep cycle can range anywhere from 10 to 25 minutes, and the length of time spent in each N2 stage can grow longer as the night progresses. The N2 stage of sleep accounts for almost half of an average person’s total time spent sleeping.

Stage 3: Stage 3 sleep is also known as deep sleep, and it is more difficult to awaken someone who is in this period of sleep. Stage 3 sleep lasts approximately 90 minutes. During N3 sleep, the body relaxes even deeper, resulting in a drop in muscle tone, pulse rate, and respiratory rate.

The activity of the brain during this time period can be characterized by a recognizable pattern of waves called delta waves. Because of this, stage 3 of sleep is sometimes referred to as delta sleep or slow-wave sleep (SWS).

Final Stage: The final stage, known as REM sleep, is characterized by an increase in brain activity that approaches the levels found when you are awake. At the same moment, the body goes through “atonia”, which is a brief paralysis of the muscles, with two notable exceptions, that are the muscles that regulate breathing and the eyes. During this period, the eyes and the muscles that control breathing remain fully functional. Even though the eyelids are closed, it is possible to observe that they are moving rapidly, which is where the name of this stage comes from.

How your body uses calories while you sleep

While we are sleeping, we are thought to burn somewhere in the vicinity of fifty calories an hour. However, a person’s basal metabolic rate (BMR) determines the number of calories that a person burns when sleeping, and that number varies from person to person.

The energy that is required for vital tasks like breathing, circulation, temperature regulation, and the growth and repair of cellular structures is referred to as the basal metabolic rate. The resting metabolic rate is responsible for roughly 80.03 percent of the day’s total caloric expenditure in the majority of persons. The brain uses glucose as its primary source of energy, which accounts for around 20% of the calories that we take in when we are at rest.

When we sleep, our bodies are able to heal and rejuvenate. Our metabolism slows down, our breathing becomes more shallow, and our core temperature reduces so that we can complete this task more efficiently. When compared to their basal metabolic rate during the day, the majority of people burn approximately 15% fewer calories while they are sleeping, on average.

The amount of sleep that a person gets can also affect the number of calories that they burn. For instance, a healthy individual who weighs 125 pounds burns roughly 38 calories per hour while sleeping; therefore, you can multiply that amount by the number of hours spent sleeping to get a rough estimate of the number of calories that are being burned.

The basal metabolic rate (BMR) of an individual differs depending on their weight, gender, and age. The amount of activity you do on a daily basis is another component that must be accounted for when determining your basal metabolic rate. That refers to how much you move around on a daily basis. Unfortunately, a single session of exercise will not offer any change in metabolic rate for your computation.

What is Basal Metabolic Rate?

The resting metabolic rate, also known as the basal metabolic rate (BMR), is the rate at which a person burns through energy while at rest. This rate does not take into account the varied influence of physical activity. The basal metabolic rate (BMR) is responsible for around sixty percent of the total daily energy expenditure.

The rate at which an individual burns calories at rest, known as their basal metabolic rate, is unique to each individual and is determined by a number of factors, only some of which may be altered.

  • Height and Weight
  • Muscle built
  • Gender
  • Age
  • Diet
  • Quality of Sleep
  • Ethnicity
  • Genetics
  • Pregnancy, lactation, menopause, hypothyroidism or hyperthyroidism, and other illnesses, as well as hormones, can boost or lower the basal metabolic rate. If you think that an underlying condition might be influencing your metabolism, you should talk to your primary care physician about it.

Other activities that burn calories when you are sleeping

When you are asleep, your body begins the process of mending any damage that was done on a cellular level when you were awake during the day. If you work out during the day, for example, your muscles will heal and mend themselves at night, which takes energy. The process by which your body converts the food you eat into fuel that can be used for the next day is known as digestion, and it uses energy in the process.

How to count how many calories you burn during sleeping?



Utilizing a Calorimeter is necessary in order to arrive at an accurate estimation of your basal metabolic rate. Using an analysis of the oxygen and carbon dioxide that is taken into the body as well as that which is exhaled, a calorimeter may determine the amount of energy that is being taken into the body.

By utilizing one of several formulae, you will be able to obtain a rough estimate of your basal metabolic rate. The Harris-Benedict equation is one of the most frequent equations, and it takes into account a person’s weight, height, age, and gender.

For males, the BMR formula is as follows:

BMR = 66.5 plus (13.8 x weight in kg) plus (5 x height in cm) – (6.8 x age in years)


For women, the basal metabolic rate formula is as follows:

BMR = 655 + (9.6 x weight in kg) + (1.8 x height in cm) – (4.7 x age in years)


The result provides you with an estimate of your basal metabolic rate while you are awake for a period of 24 hours. Divide the total by 24 to get the hourly rate, then multiply that figure by 0.85 to account for the reduced metabolic rate that occurs while sleeping. This will give you an estimate of the number of calories that are burned during each hour of sleep.

Do not be concerned if you do not enjoy mathematics. Exploring some representative averages is often a good place to get started. Take a look at the following for some examples of how many calories can be burned in eight hours of sleep:

  • 406 calories for a woman of 30 years old and 110 pounds.
  • 601 calories for a male, age 30, weighing 180 pounds.
  • 376 calories for a woman who is 50 years old and weighs 110 pounds.
  • 558 calories for a male aged 50 years old and weighing 180 pounds.
  • 424 calories for a woman, 40 years old, and 130 pounds.
  • 619 calories for a male, 40 years old, weighing 200 pounds.

As can be seen, the number of calories burned declines with age while simultaneously increasing in proportion to one’s body mass. Because aging causes a slowdown in metabolism, a decrease in the number of calories burned should not come as a surprise. The maintenance of a larger physique requires a greater amount of caloric expenditure.

Do stages of sleep affect the number of calories burnt?

There is a difference in calorie burn between the various stages of sleep. The amount of energy that is required by the body to perform even the most fundamental activities, such as breathing and circulation, fluctuates throughout the night.


The most energy-intensive sleep stage is rapid eye movement (REM) sleep. When we enter REM sleep, our heart rate quickens and our brain displays activity patterns that are analogous to those seen during the waking state. Because of the increased brain activity, more glucose is required, which ultimately results in a faster metabolism.


In contrast, while a person is in the third stage of sleep, known as “deep” sleep, their heart rate, breathing rate, core body temperature, and brain activity all drop to extremely low levels. It is assumed that stage three sleep plays a vital part in the immune system, as this is the time when the growth hormone is released during the slumbering process. However, during stage three of sleep, the brain has a decreased need for glucose, and as a result, the metabolic rate typically reaches its lowest point.

Can you increase the number of calories burnt while sleeping?

You would need to raise your basal metabolic rate in order to increase the number of calories that you burn while you are sleeping. Eating healthily, getting an adequate amount of exercise, and getting a good night’s sleep are the three most effective ways to achieve this goal.


Insufficiency in sleep promotes a surge in hormones level, which in turn induces an increase in appetite for high-calorie foods. Loss of sleep also causes levels of the stress hormone cortisol to rise, which interferes with your body’s capacity to control glucose levels and may play a role in weight gain, insulin resistance, and potentially the development of type 2 diabetes. And while staying awake for longer may result in a greater number of calories being expended, restricting calories while being sleep deprived causes the body to use lean muscle rather than fat stores as a source of fuel.


Because the body expends more energy while in the REM stage of sleep, sleep disturbances that reduce the amount of time spent in this state can have an effect on the total number of calories burned during the day. You may encourage your body to cycle naturally through the stages of sleep and maximize your metabolism while you are sleeping if you create an environment in your bedroom that is cold, dark, and quiet.

Although eating too close to sleep, as suggested by a number of studies, can contribute to weight gain, the types of foods consumed appear to be a much more significant impact in this regard. If you find yourself craving something to eat late at night, steer clear of unhealthy options like junk food and go for something light and nutritious instead. A healthier diet, in turn, improves the quality of sleep, which is a nice added bonus.

It turns out that there are a few things you can do to improve the number of calories your body burns while you are sleeping.

  • Regulate your sleep schedule
  • Improve your muscle-to-fat ratio
  • Speed up your metabolism by maintaining an exercise routine
  • Eat a healthy diet
  • Before going to bed, steer clear of caffeine and alcoholic beverages. Caffeine may cause a brief increase in metabolic rate, but it is not a healthy way to lose weight because it prevents you from falling asleep and disrupts your quality of sleep.
  • Turning down the thermostat or sleeping in pajamas that aren’t too heavy are two more sneaky things you may do to burn extra calories while you’re asleep. When the temperature is lower, your body will have to work a little bit harder to maintain its normal temperature.

However, getting a better night’s rest and making sure that your sleep cycle includes REM (rapid eye movement) intervals is the first step in the right direction. This is the time of day when your brain is working the hardest and helping you burn the most calories. This is due to the fact that your brain uses more oxygen when it is exerting a lot of effort during this stage of the sleep cycle.

The importance of good quality sleep in burning calories while sleeping

It is common knowledge that getting sufficient sleep is necessary for proper bodily function, mental health, and even the reduction of excess body fat. If you get more REM sleep, you may find that you burn more calories while you are sleeping. The following are some suggestions that can help you get a better night’s rest.

  • Make an investment in the most suitable mattress for your requirements in order to facilitate a more pleasant and restful night’s sleep. You’ll never regret a comfortable luxury mattress that lets you rest without any struggles.
  • You should try to stick to a strict routine so that you get up and go to bed at the same time every day.
  • Exercise 20-30 minutes a day. However, you shouldn’t engage in physical activity before a couple of hours of going to bed.
  • Avoid consuming caffeinated beverages in the evening.
  • If you want to swipe through content on your phone, iPad, or any other gadget with blue lights then instead read a book or magazine. A hard copy, please.
  • Do not remain in bed while awake if you are unable to fall asleep. You should relocate and read until you become exhausted

Key takeaways

  • While we are sleeping, we are thought to burn somewhere around fifty calories an hour. However, a person’s basal metabolic rate determines the number of calories that person burns when sleeping, and that number varies from person to person (BMR).
  • The energy that is required for vital tasks like breathing, circulation, temperature regulation, and the growth and repair of cellular structures is referred to as the basal metabolic rate.
  • You would need to raise your basal metabolic rate in order to increase the number of calories that you burn while you are sleeping. Eating healthily, getting an adequate amount of exercise, and getting a good night’s sleep are the three most effective ways to achieve this goal.
  • Incorporating physical activity into your daily routine is one way to boost the total number of calories you burn over the course of a day. This is in addition to getting an adequate amount of sleep. Either by making an investment in hygienic sleep items like comfy luxury mattresses and pillows or by developing a healthy routine for yourself, you may improve the quality of your sleep and make it healthier. A faster metabolism can also be achieved by reducing the size of your meals and avoiding drinking alcohol in the hours before going to bed.
  • If you find that you are still unable to get enough sleep despite the fact that you have implemented healthy sleep practices, it is highly recommended that you discuss your issues with sleeping with your primary care physician and make an appointment to see a sleep specialist.

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