6 Ways Sleep Aids Weight Loss

Many people aren’t getting enough sleep these days. In fact, around 35% of adults in the U.S. sleep less than 7 hours most nights, according to the CDC. Sleeping less than 7 hours is considered short sleep.

Here are 6 reasons why getting enough sleep might help you lose weight.

1. May help you avoid weight gain associated with short sleep

Short sleep—usually defined as getting fewer than 6 to 7 hours a night—has been consistently linked to higher body weight and a higher body mass index (BMI).

One study that looked at 20 different research projects involving 300,000 people found that adults who slept fewer than 7 hours a night had a 41% higher risk of obesity. On the other hand, those who slept longer (7 to 9 hours per night) didn’t show the same connection to obesity.

Another study found that shorter sleep was strongly associated with a larger waistline, which usually means more belly fat.

Similar results have been found in other studies, including those focused on children and teens. For example, a recent review of 33 studies found that shorter sleep was linked to a higher risk of obesity. Interestingly, for every additional hour of sleep, BMI scores went down.

Another review found that shorter sleep increased the risk of obesity across different age groups:

• Infants: 40% higher risk
• Early childhood: 57% higher risk
• Middle childhood: 123% higher risk
• Adolescents: 30% higher risk

One major review even found that shorter sleep increased the likelihood of obesity in children by 30–45%.

While lack of sleep isn’t the only cause of obesity, research suggests it can lead to higher hunger levels, making people eat more high-fat, high-sugar foods.

This might happen because lack of sleep affects hunger hormones, increasing ghrelin (which makes you feel hungry) and decreasing leptin (which makes you feel full). Ghrelin is released in the stomach and tells your brain you’re hungry, especially when your stomach is empty. Leptin, on the other hand, is released from fat cells and signals your brain when you’re full.

Poor sleep can also mess with your sympathetic nervous system, raising levels of cortisol—a stress hormone. It may also lower levels of certain hormones like insulin-like growth factor 1 (IGF-1), which is linked to increased fat storage.

On top of that, sleep disorders like sleep apnea can get worse with weight gain, leading to a cycle where poor sleep causes weight gain, and weight gain leads to even worse sleep.

2. May help moderate your appetite

Getting enough sleep might help you avoid the extra calories and appetite boosts that often come with being sleep deprived.

Many studies show that when people don’t get enough sleep, they tend to feel hungrier and eat more calories during the day.

One review found that people who were sleep deprived ate an extra 385 calories a day, with more of those calories coming from fat.

Another study showed that lack of sleep led to bigger appetites, stronger food cravings, larger portions, and an increased intake of chocolate and fatty foods.

This increase in food intake is likely because sleep affects the hormones that control hunger, ghrelin, and leptin.

When you don’t get enough sleep, your body produces more ghrelin (which makes you feel hungry) and less leptin (which signals fullness), leaving you hungrier and more likely to overeat.

3. May help you make better food choices

Getting a full night’s sleep can help you make healthier food choices.

When you don’t get enough sleep, your brain doesn’t function as well, making it harder to make good decisions, including what you eat. This can make it tough to resist tempting, unhealthy foods.

Sleep deprivation also seems to make the brain’s reward centers more responsive to food. For instance, one study found that people who were sleep deprived had stronger brain reactions to pictures of high-calorie foods. They were even willing to pay more for those foods compared to people who had enough sleep.

So, after a bad night’s sleep, not only does that bowl of ice cream seem more rewarding, but it’s also harder to resist.

Another study found that when people were sleep-deprived, they were more sensitive to the smell of high-calorie foods and ended up eating more of them.

On top of that, not getting enough sleep can lead to poorer food choices, like reaching for high-calorie, sugary, or fatty foods to boost your energy.

4. Sleeping early can prevent late-night snacking

Going to bed earlier can help you avoid late-night snacking, which often happens when you stay up too late.

When you push your bedtime later, you end up staying awake longer, giving yourself more time to eat—especially if it’s been hours since dinner.

For example, if you had dinner at 6:00 p.m. and stay up until 1:00 a.m., you’re likely going to feel hungry at some point between dinner and bedtime.

If you’re already sleep-deprived, you might be more tempted to reach for less healthy snacks because lack of sleep can increase your appetite and cravings for high-calorie, high-fat foods.

Interestingly, late-night eating is linked to weight gain, a higher BMI, and less fat burning, which can make it harder to lose weight.

Also, eating too close to bedtime, especially large meals, can lower the quality of your sleep and make sleep deprivation worse. This is particularly true for people with acid reflux, indigestion, or sleep disorders, who should limit eating before bed.

Ideally, try to stop eating 2–3 hours before going to sleep. However, if you’re hungry, a small, protein-rich snack like Greek yogurt or cottage cheese is a better choice.

5. Potential benefits for your metabolism

Getting enough sleep can help prevent your metabolism from slowing down, which often happens when you don’t get enough rest.

Your resting metabolic rate (RMR) is the number of calories your body burns when you’re at rest. It’s influenced by factors like age, weight, height, sex, and muscle mass. Surprisingly, how long you sleep can also impact your RMR.

In one study with 47 participants, researchers looked at how restricting sleep affected RMR. The participants slept normally for two nights, then had five days of restricted sleep with only four hours per night. Afterward, they had one night of “catch-up” sleep, where they stayed in bed for 12 hours.

During the five days of limited sleep, the participants’ RMR dropped significantly compared to their baseline. However, after the catch-up sleep, their RMR returned to normal. The control group, which didn’t experience sleep restriction, didn’t see any significant changes in their RMR.

This study suggests that lack of sleep can lower your RMR, but getting enough rest, even just for one night, can help restore it.

On the other hand, some studies found no change in metabolism with sleep loss and even suggested that staying awake longer might increase energy expenditure. So, more research is needed to fully understand how sleep affects metabolism.

Lack of sleep may also slow down fat oxidation, which is the process of breaking down fat cells for energy. One study showed that sleep deprivation led to significantly lower fat oxidation in people of different ages, sexes, and body types, though their RMR didn’t change.

Poor sleep quality might also reduce muscle synthesis, which can lower RMR. In one small study, muscle synthesis decreased by 18%, and testosterone levels dropped by 24% after just one night of poor sleep. Cortisol, a stress hormone, also increased by 21%, contributing to muscle breakdown.

However, this study was small and only lasted one day, which are big limitations. Other studies suggest that sleep deprivation doesn’t affect muscle repair and growth. So, longer and larger studies are needed to get a clearer picture.

Also Read: 9 Unexpected Benefits of Coffee

6. Sleep can enhance physical activity

Sleep and physical activity are closely linked in a two-way relationship. Not getting enough sleep can make you less active, and not being active can worsen your sleep.

Studies have shown that regular exercise can help you fall asleep faster and improve sleep quality, no matter your age.

On the flip side, when you don’t get enough sleep, you’re more likely to feel tired during the day, which can make you less motivated to exercise and more prone to being inactive.

This lack of physical activity can lead to burning fewer calories each day, making it harder to create a calorie deficit for weight loss.

Plus, not getting enough sleep can hurt your athletic performance by affecting your reaction time, fine motor skills, muscle power, endurance, and problem-solving abilities. It can also increase your risk of injury and slow down recovery.

In short, getting enough sleep is crucial for staying active and performing well.