Sleeping is likely the last thing that comes to mind when thinking of ways to burn calories. Yet, the brain and body are still working hard during sleep, helping take care of important restoration functions. In fact, the brain’s energy consumption continues at about the same rate through both sleeping and waking.
This energy consumption results in a calorie burn and a small amount of weight loss during sleep each night (though it’s usually gained back with food and water intake during the day). So, how many calories do you burn sleeping? Here’s a look at calorie burn during sleep, plus how you can amp up your weight loss and metabolism during shut-eye.
How Many Calories Do You Burn Sleeping?
The number of calories you burn sleeping depends on factors like body weight and the number of hours you sleep. The average person loses one to two pounds per night — something that many people notice when stepping on the scale in the morning. This is in part due to water loss, as the body loses water through breath and sweat without it being replenished.
“A single cup (237 ml) of water weighs close to 1/2 pound (240 grams). Your body comprises about 55-75% water, which accounts for a significant proportion of your weight,” says dietician Ansley Hill.
Weight loss is also a result of the body’s complex metabolic processes (like cellular respiration and protein synthesis), which are continually happening in the background. The role of metabolic processes in calorie burning depends on personal health factors, like body fat and age.
How to Find Your Resting Metabolic Rate
Another thing that influences the amount of calories burned during sleep is resting metabolic rate. This is described as “the total number of calories burned when your body is completely at rest. RMR supports breathing, circulating blood, organ functions, and basic neurological functions,” according to the National Academy of Sports Medicine (NASM).
In other words, your resting metabolic rate is how many calories your body burns in a 24-hour cycle as a result of metabolism. This metric shows how many calories a person would burn at rest or during sleep, regardless of exercise. Your resting metabolic rate is proportional to lean muscle mass or lean body mass, and unchangeable factors like age and genetics influence it.
To find your approximate resting metabolic rate, use the Mifflin St. Jeor Equation using weight in kilograms, height in centimeters, and age in years:
- Male: 9.99 x weight in kg + 6.25 × height in cm – 4.92 × age + 5
- Female: 9.99 x weight in kg + 6.25 × height in cm – 4.92 × age – 161
Basal metabolic rate helps determine how many calories an individual burns both during the day and during sleep. However, this metric can’t be used alone to determine calorie burn. Elements such as exercise, post-exercise oxygen consumption, and the thermogenic effect of food all play a role in resting metabolic rate.
Physical activity and energy expenditure also influence a person’s metabolic rate, as a more active day will require more recovery at night, thereby increasing how hard the body works to repair muscles and tissue.
Factors That Influence Calorie Burn During Sleep
How many calories do you burn sleeping once you account for all the other factors? There are a number of sleep conditions and patterns that affect how many calories you burn as you sleep. Here’s a look at how body temperature, sleep deprivation, and hunger levels influence calorie burn during sleep.
Body Temperature During Sleep
Your body temperature drops naturally to facilitate sleep. Therefore, keeping the room cooler can kick this process into motion, helping you sleep faster and boost weight loss during sleep. This is because your body needs to burn more calories when it’s cold in order to stay warm. The ideal temperature for sleep is between 60-67 degrees. Being too cold or hot can make you uncomfortable and disrupt your sleep, leading to sleep deprivation.
Sleep deprivation can exacerbate existing conditions, especially if you’re trying to cut down on calories and lose weight. Why? Because failing to get enough hours of sleep can increase ghrelin and leptin — two hormones that can cause overeating and weight gain. While ghrelin signals hunger in the brain, leptin signals fullness after enough food has been eaten. In turn, not getting enough sleep can falsely increase your appetite, suppress your fullness timer, and cause you to increase your calorie intake.
You might also be inclined to make less healthy choices when you’re sleep-deprived. For example, you might reach for a larger latte, eat more carb-heavy foods, and feel more intense sugar cravings. These are all signs the body is trying to compensate for lack of sleep.
Being sleep-deprived also leads to increased calorie retention because it triggers a spike in cortisol. This hormone sends signals to the body that it’s time to conserve energy, which makes the body hold on to fat.
In contrast, getting enough sleep each night can ensure you burn calories and keep them off. Specifically, spending enough time in deep sleep and REM (rapid eye movement sleep) ensures that the weight doesn’t continue to build up.
Eating and Nutritional Habits
How and when you eat play a significant role in your body’s calorie-burning rate during sleep. For example, many people know that eating large meals before bed isn’t a good idea. That’s because a large meal requires energy to digest, and it can keep you awake and disrupt your sleep cycle.
Meanwhile, going to bed hungry can also keep you awake and cause your body to go into fat-saving mode. Since both of these extremes can disrupt sleep, they can both lead to sleep-deprived overeating, as described above.
In addition to keeping your dinner portion control in check, be mindful of what you’re eating. A nutrition study showed that eating at least 30 grams of protein before bed can have a positive impact on metabolism, helping the body burn more calories during sleep. Protein sources like lean meat, almonds, boiled eggs, or cottage cheese can make a great snack 30 minutes before bedtime. These foods keep you full during the night while also boosting energy metabolism.
While the debate continues about whether or not you should have midnight snacks, eating a protein-packed dinner or snack before bedtime can help you burn calories, stay full, and lose weight both throughout the night and well into the next day.
So, How Many Calories Do You Burn Sleeping?
Everyone burns calories during sleep due to normal metabolic processes. But there’s not a one-size-fits-all answer to “How many calories do you burn sleeping?” The number of calories depends on age and genetics. And, most people lose roughly a pound or two of water weight during the night, which is usually gained back during the day.
While age and genetics can’t be changed, adopting different lifestyle habits — including better sleep and nutrition — can influence how many calories you burn while sleeping. The bottom line: Burning calories during sleep is a normal, easy way to lose weight, and there are a few things you can do to accelerate this process even more.