Sleep is one of those things that we take for granted in our youth, but relish as we get older. Despite looking forward to crashing at the end of a long day or staying in your comfy bed when your alarm goes off, many of us aren’t getting enough sleep.
In fact, one in three Americans doesn’t get enough shut-eye. A lack of sleep can affect your health in several ways — including your weight.
But how does sleep affect weight loss? Is there a best time to sleep to lose weight? Does lack of sleep cause weight gain?
Below, we’ll answer these questions and go over everything else you want to know about the sleep and weight loss relationship.
No matter how much you love your bed, if you’re not getting the right amount of sleep, you may find yourself in a lose-lose situation when it comes to maintaining a healthy weight.
The CDC (Centers for Disease Control and Prevention) recommends adults get seven or more hours of sleep each night.
Not getting enough sleep (whether by choice or from sleep disorders like sleep apnea) has been linked to several health conditions. This includes heart disease, obesity, type 2 diabetes and depression — all of which can affect your weight.
Research has also found the sleep and weight loss relationship goes both ways. When the hours of shut-eye you get each night decreases, it can be harder to lose weight or potentially lead to weight gain.
So how does sleep help you lose weight? What’s the connection between sleep and weight loss, or why can less sleep mean more weight?
Several possible factors connect sleep to weight loss or weight gain — from poor food choices, changes in appetite and eating at odd hours to decreased physical activity and metabolism changes.
If you’re on a weight loss journey, the first thing you probably want to know is: Does sleeping help you lose weight?
While good sleep may not directly lead to a lower number on the scale, some evidence suggests the effects of sleep help with weight management.
The connection between sleep and weight loss may involve how sleep affects appetite. Our appetite is controlled by neurotransmitters, chemical messengers that allow nerve cells to communicate with one another.
The neurotransmitters ghrelin and leptin are thought to be central to appetite, with ghrelin promoting hunger and leptin contributing to a feeling of fullness.
A good night’s sleep can promote healthy ghrelin and leptin levels so you can go about your day with a regular appetite.
A small study looked at 80 overweight adults who slept less than 6.5 hours each night. It found that over a two-week period, those who slept more reduced their calorie intake compared to a control group.
While this particular study had a small sample size, there’s decent evidence that improving sleep quality and increasing how much sleep you get each night could help with weight loss.
Another well-known component of weight and fat loss is exercise, which, in turn, may help you sleep better. A 2017 review of studies on over 900 adults concluded that those who engaged in regular physical activity had better sleep quality.
Another review of multiple studies saw a clear connection between exercise and improved sleep quality or longer stretches of sleep.
The exact relationship between physical activity and better sleep quality isn’t fully understood. But exercise certainly appears to improve sleep, which can help you maintain a healthy weight.
There’s promising research behind the idea that better sleep can help you lose weight. But does a lack of sleep cause weight gain?
Numerous studies have suggested that poor sleep quality may lead to higher body weight, as well as a higher risk of obesity and other chronic health conditions.
Several studies have suggested that reducing sleep by just one hour a night could result in an increase in body mass index (BMI) by about three pounds. BMI screens for weight categories by comparing a person’s height to their body mass.
Overall, these studies (which collected results from multiple individuals around the world) found an increased risk of obesity amongst those who got less sleep.
Other international studies with a wide range of participants have also found a small but significant relationship between short sleep duration and waist measurement. Those who got less sleep saw an increase in waist circumference.
The measurement of your waist is one way to determine if you’re at a higher risk for health conditions associated with obesity or being overweight.
Sleep deprivation may also contribute to poor eating patterns and food choices by messing with your appetite.
A 2015 review of multiple studies found consistent links between short sleep duration and irregular eating patterns. Those who got less than seven hours of sleep a night ate fewer main meals and more small, high-fat snacks.
A more recent but smaller study from 2021 also found that reduced sleep led to poor food choices and a higher caloric intake. This could be due to the effect sleep quality has on the chemicals we mentioned above that control appetite and cravings, ghrelin and leptin.
Adequate sleep helps keep ghrelin and leptin balanced. But poor sleep patterns could have the opposite effect, causing you to consume more food and eventually leading to weight gain.
In a 2004 study, sleep restriction was found to reduce leptin levels (the hormone that helps you feel full) and raise ghrelin, causing increased hunger and more food intake.
You’ve probably heard of metabolism and its connection to weight gain or weight loss. However, your metabolism isn’t necessarily connected to or responsible for weight.
Instead, it’s the process by which your body converts food into energy. And energy is necessary for various bodily functions like breathing, digestion and managing hormone levels.
But that doesn’t mean there isn’t a connection between insufficient sleep and metabolism. Some theories suggest that either a lack of sleep or poor-quality sleep can negatively impact metabolism and energy expenditure.
Finding the motivation or energy to work out is hard enough. 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.
Beyond working out, you also burn fewer calories when you get insufficient sleep.
While activities like exercise can temporarily increase metabolism, metabolism actually slows about 15 percent during sleep. Disrupted sleep can affect your metabolism even more.
According to a small study on men and women, less sleep leads to a decrease in resting metabolic rate — the number of calories burned when your body’s at rest or conserving energy.
Big changes in your sleep schedule can also cause changes in metabolism and reduce insulin sensitivity, leading to an increased risk of diabetes.
While there seems to be a significant connection between sleep and weight loss (or weight gain, for that matter), it may feel impossible to get more sleep. But getting better sleep is possible with small lifestyle changes for better sleep habits.
For better sleep, try:
Going to bed and waking up at the same time each day — even on weekends
Limiting your screen time about an hour before going to sleep
Removing electronic devices from the bedroom
Keeping your bedroom dark, quiet and at a comfortable temperature
Avoiding caffeine and alcohol before bedtime, as well as large meals
Getting regular physical activity
Start with one or two changes, then add more healthy habits to see what works for you.
If you’re having trouble losing weight or find yourself gaining weight, one thing you may want to consider is your sleep.
Does sleep loss cause weight gain? Here’s what to keep in mind:
Though the recommended amount of sleep is more than seven hours per night, a third of people aren’t meeting this. Lack of sleep can increase your risk of health conditions like diabetes and high blood pressure while contributing to weight gain.
Sufficient sleep may help you lose weight. A full night’s rest can help control appetite by balancing the hormones ghrelin and leptin.
Sleep deprivation can also affect weight in the opposite direction. Causing a spike in the stress hormone cortisol, poor sleep quality is associated with poor eating habits.
Sleep can also affect your metabolism (how your body converts food to energy). Getting less sleep may decrease your resting metabolic rate while increasing insulin sensitivity and the risk of diabetes.
Research on the connection between weight and sleep is still unfolding. But a long-term lack of sleep can make weight loss harder and increase your risk of weight gain.
Fortunately, there are ways to try and get a full night of sleep, from better sleep hygiene to regular exercise and more. Getting proper sleep can support weight loss programs and help with weight management.
If you’re getting your proper rest and still feel like you’re coming up short, there are plenty of ways to lose weight and feel your best. Don’t hesitate to learn more about weight loss treatment.
Dr. Craig Primack MD, FACP, FAAP, FOMA is a physician specializing in obesity medicine.
He completed a combined residency in Internal Medicine and in Pediatrics at Banner University- Phoenix, and Phoenix Children's Hospital. He received post-residency training in Obesity Medicine and is one of about 7,000 physicians in the U.S. certified by the American Board of Obesity Medicine.
In 2006, Dr. Primack co-founded Scottdale Weight Loss Center in Scottsdale, Arizona, where he began practicing full-time obesity medicine. Scottsdale Weight Loss Center has grown since then to six obesity medicine clinicians in four locations around the greater Phoenix Metropolitan area.
From 2019–2021, he served as president of the Obesity Medicine Association (OMA), a society of over 5,000 clinicians dedicated to clinical obesity medicine. He has been on the OMA board since 2010, currently serving as ex-officio trustee.
Dr. Primack routinely does media interviews regarding weight loss and regularly speaks around the country educating medical professionals about weight loss and obesity care. He is co-author of the book, “Chasing Diets.”
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