How Are Sleep and Weight Loss Connected?

If you’re crashing at the end of a long day or staying in your comfortable bed long after your alarm goes off, you might be among the one in three Americans who don’t get enough sleep. Lack of sleep affects your health in several ways — it can even affect your ability to lose weight.

When you lose out on sleep, your weight management journey gets out of whack. 

So, how does sleep affect weight loss? Does lack of sleep cause weight gain? 

Below, we’ll answer these questions and cover everything you need to know about the link between sleep and weight loss.

If you’re on a weight loss journey, you probably want to know: Does sleep help you lose weight?

While good sleep may not lead directly to a lower number on the scale, there is some evidence that sleep can help with weight management.

Several possible connections exist between sleep and weight.

Let’s look at appetite first. Your appetite is controlled by certain hormones, including ghrelin and leptin. Specifically, ghrelin promotes hunger and leptin contributes to feeling full.

When you get a good night’s sleep, your body produces healthy levels of ghrelin and leptin, and you can go about your day with a regular appetite.

Another connection between weight and sleep is your activity level. Exercise helps you sleep better, so you may have trouble sleeping if you’re not getting enough movement into your day. A 2018 review of over 900 adults found that those who engaged in regular physical activity had better sleep quality.

A review of studies also found a connection between exercise and improved sleep quality.

How Many Hours of Sleep Is Good for Weight Loss?

The Centers for Disease Control (CDC) recommends adults get seven or more hours of sleep each night. 

While watching another hour of Netflix may not seem like such a bad idea in the moment, it can add up. Not getting enough sleep is linked to several health conditions, including heart disease, obesity, type 2 diabetes, and depression. 

A study of 80 overweight adults found that over a two-week period, those who slept more than 6.5 hours each night were able to significantly reduce their calorie intake compared to those who slept less.

While this study had a small sample size, the research suggests that improved sleep quality may help encourage proper weight management.  

Getting enough sleep may help you lose weight, but does that mean not sleeping enough leads to weight gain?

While research suggests better sleep can help you lose weight, studies have also suggested that poor sleep quality may lead to weight gain, as well as raise the risk of obesity and other chronic health conditions.

Several studies suggest that reducing sleep by even one hour may be enough to impact your body mass index (BMI).

Overall, these studies, which collected results from people around the world, found an increased risk of obesity amongst those who get less sleep.

Other studies with a wide range of participants have also found a small but significant relationship between short sleep duration and waist size — those who got less sleep saw an increase in waist circumference.

Like BMI, waist circumference is a measurement that helps determine if you’re at higher risk for health conditions associated with obesity or being overweight.

Lack of Sleep and Appetite 

A lack of sleep may mess with your appetite and make you more likely to make unhealthy food choices — we’re looking at you frozen pizza. 

A 2015 review of multiple studies found consistent links between short sleep duration and irregular eating patterns. Those who slept less than seven hours ate fewer main meals and more small, high-fat snacks at night.

In addition, disrupted sleep patterns or sleep deprivation could cause more cravings for foods high in fat and carbohydrates, as one study found.

A more recent but smaller study from 2021 also found that reduced sleep led to poor food choices and higher food intake.

This could be due to how sleep quality affects ghrelin and leptin, hormones that help regulate appetite. 

While adequate sleep helps keep ghrelin and leptin balanced, poor sleep could have the opposite effect, causing you to consume more food than usual and leading to weight gain.

You’re also probably well aware that you feel more stressed after a bad night’s sleep — a fact attributed to increased cortisol, the stress hormone.

When your cortisol levels are high for long periods, you’re also more likely to gain weight.

First, you should know that your metabolism isn’t necessarily connected to or responsible for weight.

Metabolism is simply the process by which your body converts food into the energy necessary for bodily functions like breathing, digestion, and other essential processes.

There are some theories that either a lack of sleep or poor quality sleep could have a negative impact on metabolism and energy expenditure.

One potential reason why? Working out. Finding the motivation or energy to work out is already hard enough. But when you don’t get enough sleep, your energy levels take a hit, making it even more difficult to hit the gym or do much physical activity at all.

Since exercise can temporarily increase your metabolism, a lack of exercise could negatively affect your metabolism.

Beyond working out, you also burn fewer calories when you get insufficient sleep. Metabolism slows about 15 percent during sleep, but disrupted sleep can affect your metabolism even more.

According to one small study, getting less sleep leads to a decrease in resting metabolic rate, or the number of calories burned when your body’s at rest or conserving energy.

Another theory on the relationship between sleep and metabolism is your sleep schedule. Significant changes in when you go to sleep and for how long can also cause changes in metabolism and reduce insulin sensitivity, leading to an increased risk of diabetes.

It may feel impossible to get more sleep. But getting better sleep is possible with these small lifestyle changes for better sleep habits:

• Go to bed and wake up at the same time each day — even on weekends.

• Limit your screen time, starting about an hour before going to sleep.

• Remove electronic devices from the bedroom.

• Keep your bedroom dark, quiet, and at a comfortable temperature.

• Avoid caffeine and alcohol, as well as large meals, before bedtime.

• Get regular physical activity during the day.

If you're having trouble losing weight or find yourself gaining weight, you may want to consider your sleep. Here’s why:

• Most people should get at least seven hours of sleep per night, but about one-third don’t. Lack of sleep can increase the risk of health conditions like diabetes, high blood pressure, and more. It can also contribute to weight gain.

• Poor sleep quality can lead to unhealthy food choices.

• Sufficient sleep may help you lose weight, as a full night’s rest can help keep the hormones responsible for appetite — ghrelin and leptin — balanced.

• Sleep can also affect your metabolism. Getting less sleep may decrease your resting metabolic rate and increase your risk of diabetes.

A long-term lack of sleep may make weight loss harder and increase your risk of weight gain. In short, getting proper sleep is an important support for weight loss programs and other methods of weight management.

Fortunately, there are ways to try to get a full night of sleep, from better sleep hygiene to regular exercise.