How Many Calories Do You Burn While Sleeping?

While sleep might seem like something that requires no energy at all, your body is secretly hard at work, burning calories as it keeps your heart beating, repairs muscles, dreams, and consolidates your thoughts and memories from the day. So, do you burn calories when you sleep? Yes! Read on to learn how many calories you burn while sleeping, plus the factors that go into your expected nightly calorie burn (and how to optimize it). 

Note: The content on Sleepopolis is meant to be informative in nature, but it shouldn’t be taken as medical advice, and it shouldn’t take the place of medical advice and supervision from a trained professional. If you feel you may be suffering from any sleep disorder or medical condition, please see your healthcare provider immediately. 

Do You Burn Calories When You Sleep? 

Yes, you do burn some calories while you sleep. While more sleep doesn’t equate to a strategic weight loss plan, your body is at work even at rest, requiring energy to continue performing various essential processes. 

For example, maintaining your core body temperature, which is generally around 98.6°F (37°C), requires metabolic activities that utilize calories. (3) Another critical (and continuous) process that burns calories during sleep is breathing. Every inhale and exhale involves using your diaphragm muscles to facilitate the exchange of oxygen and carbon dioxide. 

Furthermore, your body is still undergoing basic metabolic functions like circulating blood, repairing tissues, and processing nutrients. These processes are vital for maintaining health and cellular function, and they rely on metabolic pathways that use energy stored in calories. You may be unconscious through the night, but your brain is active, managing everything from hormone regulation to organizing and storing your memories, which require fuel. (4)(5)

The rate at which you burn calories during sleep is influenced by factors like your basal metabolic rate (BMR), age, weight, and overall health. 

On average, a person might burn around 50 calories per hour while sleeping, or 400 calories per 8-hour rest period. (1) Thus, while sleep is technically a time of rest, it’s also a time when your body performs essential tasks of repair and regeneration that contribute to calorie burning.

How Many Calories Do You Burn While Sleeping?

Though most adults burn around 50 calories per hour of sleep, the number of calories you burn  varies depending on individual factors. How old you are, how much you weigh, your gender, and your overall metabolic rate play a role in determining this. 

Your BMR plays a key role in how many calories you burn while asleep. It’s the number of calories your body needs to maintain basic functions — like breathing, circulating blood, maintaining body temperature, and repairing tissues — which occur even while at rest. (6)

Thomas Kilkenny, DO and director at the Institute of Sleep Medicine at Staten Island University Hospital, adds that, “Energy consumption occurs 24 hours a day — even at rest, the body needs energy to keep all its systems functioning correctly.”  

Again, most people burn at least 50 calories per hour of sleep. (1) This means that during an eight-hour night of sleep, you might expect to burn around 400 calories. Still, people with higher muscle mass, more active lifestyles, or larger body sizes tend to have higher BMRs and thus burn more calories, even during rest. (7) Similarly, younger people generally have faster metabolic rates compared to older adults, so they can generally expect to burn more calories overnight. (8)

While you don’t burn as many calories sleeping as you would playing pickleball, for instance, sleep is a critical piece of regulating your metabolism. Getting enough sleep helps control appetite-regulating hormones like leptin (the satiety or fullness hormone) and ghrelin (the hunger hormone). (9)

On the other hand, Kilkenny notes that a lack of sleep causes hormone surges that make you crave high-calorie foods. “Sleep loss also raises cortisol levels, which affects your body’s ability to regulate glucose and may contribute to weight gain, insulin resistance, and even type 2 diabetes,” he says. (10)

Finally, other factors can also impact the number of calories you burn while asleep, such as the temperature of your room. Sleeping in a cooler environment might make your body expend more energy to maintain your core temperature, resulting in burning more calories. (11)

What Factors Affect the Basal Metabolic Rate?

Two people can have vastly different BMRs because several factors determine how many calories your body burns while awake or asleep. Some of these factors include: 

• Age: BMR decreases with age as muscle mass tends to decline, leading to a slower metabolism. (12)
• Gender: Men generally have a higher BMR than women due to differing body composition and greater muscle mass. (13)
• Weight and Height: Taller and heavier (greater muscle mass) people typically have higher BMRs because their bodies require more fuel. (14)
• Diet: Eating habits, including your protein intake, can influence BMR, as the body uses more energy to process certain foods. (15)
• Genetics: Your genetic makeup plays a role in determining your BMR. (13)
• Race: Some research suggests that BMR may vary slightly across different racial groups due to metabolic diversity. (16)
• Hormones: Hormonal imbalances, such as thyroid dysfunction, can either increase or decrease BMR. For example, hyperthyroidism (overactive thyroid) tends to increase BMR, whereas hypothyroidism (underactive thyroid) decreases it. (17)
• Sleep Quality: Poor sleep can disrupt metabolic processes, slowing down BMR. (18)

How to Calculate Your Calories Burned While Asleep 

Curious how many calories you burn while asleep? You can use the Harris-Benedict equation to calculate your BMR. This equation takes into account your weight, height, age, and gender to determine how many calories your body burns at rest. (19)

Here’s an example:

• For men: BMR = 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) – (6.75 × age)
• For women: BMR = 655.1 + (9.563 × weight in kg) + (1.850 × height in cm) – (4.676 × age)

Once you’ve calculated your BMR, divide it by 24 to find the number of calories burned per hour at rest. Multiply this result by the number of hours you sleep to estimate the total calories burned while sleeping.

For example, if your BMR is 1,600 calories per day, you would burn about 66.67 calories per hour (1,600 ÷ 24). Over an 8-hour sleep period, this would result in approximately 533 calories burned (66.67 x 8 hours). 

Which Sleep Stage Burns the Most Calories?

Each sleep stage burns calories at a different rate, playing a role in your overall nightly calorie expenditure; however, REM sleep is the biggest calorie-burner out of the four sleep stages. 

Those four sleep stages are N1, N2, N3, and REM (rapid eye movement). “Stages N1 to N3 are considered non-rapid eye movement (NREM) sleep, with each stage leading to progressively deeper sleep,” says Kilkenny. He notes that a typical night of sleep consists of 4 to 5 sleep cycles and that a complete cycle takes around 90-110 minutes. (20)(21)

“Most calorie-burning happens during REM sleep, the phase of sleep when you dream,” says Kilkenny. This is because during REM sleep, heart rate increases, and the brain exhibits activity patterns similar to daytime levels. The increased brain activity requires more glucose, leading to a higher metabolism. (22) 

Of course, you’re still burning calories in the other stages, with an increase each time you drop deeper into sleep.

N1 is the lightest stage, where you’re just beginning to fall asleep and can be easily awakened. During the light sleep phase, your body burns relatively few calories because it’s not working all that hard yet to repair tissues or restore energy. 

N2 represents a slightly deeper sleep, where your body starts to relax more, but you can still be aroused without too much difficulty. Memory consolidation starts here. (23) Calorie burn continues to increase slightly as we inch closer to REM sleep. N3, also called deep or slow-wave sleep, is the deepest stage, where it’s hardest to wake up.

N3 is also the most restorative stage, where your body is focused on tissue repair, muscle building, more memory consolidation, and immune strengthening. (24) Calorie burn is moderate during deep sleep, as your heart rate and breathing pattern slow down quite a bit. 

How to Burn More Calories in Your Sleep 

One of the most impactful ways to increase calorie burn while sleeping is by improving the amount of time you spend in REM sleep. The first step is to optimize your sleep quality, which is best achieved by implementing good sleep hygiene practices. (25)

Another key to burning more calories while asleep is to boost your BMR. While there’s no direct way to control the number of calories you burn when asleep, there are everyday things you can do to help enhance your BMR in general. 

Here are some actionable tips to help improve your sleep quality and potentially boost BMR and calorie burn:

• Build muscle mass: “Muscle fibers burn more calories than fat, so people who are fit and frequently exercise burn more calories,” notes Kilkenny. (26) Plus, strength training continues to burn calories even after you’re done lifting. Aim to strength train at least twice per week, which could include using dumbbells, weight machines at the gym, resistance bands, or doing bodyweight exercises. 
• Stay active during the day: Regular exercise, including both cardio and strength training, can boost metabolism and promote better sleep. (27) Aim for at least 150-300 minutes (2.5-5 hours) of moderate exercise per week, which could be a combination of activities you enjoy, like playing tennis, jogging, climbing stairs, or doing martial arts. (28) 
• Eat protein-rich meals: Protein has a higher thermic effect compared to fats and carbs, meaning your body burns more calories digesting protein, which may help increase BMR. (15)
• Maintain a consistent sleep schedule: Going to bed and waking up at the same time (yes, even on the weekends) helps regulate your circadian rhythm, improving sleep quality and metabolism. (29)
• Sleep in a cooler room: Research is limited, but one animal study showed that sleeping in a slightly cooler environment may make your body work harder to maintain its temperature, increasing calorie needs. Referencing another small study among five 20-something men, Kilkenny says, “People who keep their bedrooms at a steady temperature of 66 degrees can expect to increase the number of calories burned by up to 42 percent and boost their metabolism by 10 percent.” (11) (30)
• Manage stress: High stress can disrupt sleep and hormone balance, negatively affecting metabolism and BMR. Relaxation techniques like meditation before bed can improve sleep quality. (31)
• Avoid heavy meals before bed: Heavy meals may make you feel like there’s a brick in your stomach. A light meal before sleep aids digestion and prevents sleep disturbances, promoting more restful sleep. Plus, Kilkenny says, “Consuming large meals or the majority of daily nutrients late in the evening may increase susceptibility to obesity and other cardiometabolic diseases.” (32)

Are There Foods That Burn Fat at Night While You Sleep?

There are claims that lean proteins or healthy fats, like a handful of nuts, may help you burn fat when you’re asleep. While these types of foods may support metabolism or help stabilize blood sugar overnight, claims about “fat-burning” foods during sleep aren’t backed by robust scientific data. 

Some research suggests that eating protein before bed may promote muscle repair and slightly increase calorie burn, but it doesn’t equate to significant fat loss. (33) Ultimately, fat loss depends more on overall calorie balance, physical activity, and metabolism rather than specific nighttime foods.

FAQs

The Last Word From Sleepopolis 

Sleep is an essential aspect of our health and literal survival. If you were looking for one more reason to be amazed by the benefits of a good night’s sleep, now you know that your body and brain are still hard at work even while you’re snuggled up in your coziest blanket. 

While sleeping more isn’t the same as hitting the gym and choosing healthier foods, it is an important piece of your overall weight management and health optimization plan. If you’re hoping to boost your calorie burn while sleeping, consider how you can improve your sleep hygiene and daily habits to boost your BMR and the amount of time spent in REM sleep. 

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Lauren Panoff

Lauren Panoff, MPH, RD is a Colorado-based health and nutrition writer who has been published with a number of trusted wellness platforms. She is a dietitian who specializes in plant-based living, as well as a mother of two humans and a dog.