Written by Ashley Zlatopolsky, Content Writer
While many of the effects of sleep deprivation1 are well-known, such as a reduced ability to function at school or work, one surprising impact of poor sleep is the increased risk of weight gain2. Ongoing research continues to find that people who don’t get the recommended seven to nine hours of sleep per night have higher instances of weight gain and obesity.
Still, getting enough sleep isn’t always possible, especially if you’re a shift worker, have a new baby at home, or are going through a period of increased stress. Yet, being aware of the link and taking steps to promote better rest may help you avoid sleep loss-related weight gain.
Effects of Sleep Deprivation on Weight Loss
It’s no secret that sleep is a building block for both physical and mental health, but some studies3 have found that sleep also plays an important role in weight management. More specifically, getting enough proper rest is essential for weight loss, particularly fat loss.3
So what happens when the opposite occurs and you aren’t getting enough sleep?
Our Metabolism During Rest
Your metabolism4 serves as a critical bodily function that converts food into energy, and this energy then fuels different processes, including cell growth and hormone regulation.
When you go through a period of poor sleep, research5 shows that sleep deprivation can throw your metabolism off balance and cause changes in how your body releases hormones. This can then affect how your body regulates glucose, or blood sugar, ultimately leading to weight gain.5
Dr. Sameh Aknouk, DDS, who treats patients with sleep apnea (which can cause sleep disturbances), has witnessed firsthand how sleep loss can impact one’s metabolism.
“Patients with sleep apnea often report weight gain issues,” he says. “Research and clinical observations suggest that during deep sleep, our metabolism works harmoniously, processing glucose more efficiently. However, a lack of sleep can disturb this balance, slowing the metabolism and leading to weight gain.”
Does Lack of Sleep Cause Weight Gain?
Sleep is essential to maintaining a healthy weight and lack of sleep has been attributed to an increased risk of weight gain and obesity.2 But why does this risk occur?
In addition to the metabolic changes we mentioned above, researchers speculate that poor sleep may cause people to overeat and/or decrease the amount of energy they burn. Chronic sleep deprivation (or prolonged sleep loss) can increase hunger, give people more time to eat, encourage people to choose less healthy diets, decrease physical activity (as a result of being too tired to exercise), and lower body temperature, which may reduce calories burned.2
A scientific review of various studies on sleep loss and weight management also discovered that disturbed sleeping patterns of getting limited or low-quality sleep may cause people to snack more on foods high in fat and carbohydrates, further increasing the risk of weight gain.3
On the flip side, getting enough high-quality sleep can reduce your caloric intake6. However, it’s important to keep in mind that just because these links exist, it doesn’t mean that everyone experiencing sleep loss will experience weight gain; the risk is simply higher.2
Impact of Sleep on Appetite and Hormones
Sleep deprivation can cause a person to overeat for a number of reasons ranging from having more time to eat to choosing less-healthy foods.2 In addition, studies7 show that sleep deprivation can negatively impact the function of hormones that help regulate your appetite, potentially causing a person to be more hungry and ultimately leading to weight gain.
“Sleep deprivation can significantly increase the levels of ghrelin, the hormone responsible for the sensation of hunger,” Aknouk says. “Concurrently, it lowers leptin levels, which tell us we’re full. Additionally, sleep disruption can affect the body’s cortisol levels, a stress hormone that can lead to fat accumulation, particularly around the midsection.”
Can Sleep Disorders Contribute to Weight Gain?
Poor sleep may be caused by temporary issues, such as increased stress or jet lag, or more chronic concerns such as sleep disorders. Those who fall into the latter category may be at an increased risk of weight gain due to lack of sleep, but as we mentioned earlier, it’s important to note that sleep loss or the following sleep disorders don’t always result in weight gain.
Learn More: Obesity and Sleep
Sleep Apnea
Obesity is linked to obstructive sleep apnea8 (OSA), a sleep disorder in which your breathing stops and restarts repeatedly during sleep due to a blockage in the airway. While OSA can occur in any person regardless of weight, it’s thought that fat deposits, particularly in the throat, may contribute to OSA and trouble breathing during sleep. This is why weight loss is often recommended for those with OSA who are also obese.8
While obesity may increase your risk of sleep apnea, the sleep disorder itself could put you at an increased risk of weight gain too. As mentioned above, sleep is important for weight management.3 However, a potential symptom of sleep apnea is difficulty staying asleep9. Therefore, poor sleep from sleep apnea may contribute to weight gain.
Read More: Our Guide to Sleep Apnea
Insomnia
Insomnia10 is a sleep disorder that can make it hard to fall and/or stay asleep. A chronic loss of sleep can lead to some of the issues we’ve mentioned above, such as overeating at night, less energy to exercise, and a hormonal imbalance that disrupts the functioning of hunger levels.2
Learn more about insomnia here.
Sleep Tips for Weight Loss
Whether you’ve been diagnosed with a sleep disorder linked to weight gain, or you’ve experienced weight gain from a more general lack of sleep, there are steps you can take to get your sleep back on track to promote better weight management.
- Keep a strict sleep and wake schedule: Going to bed and waking up at the same time every day can help train your body when it’s time to get some shuteye.
- Have a regular nightly routine: Maintaining a consistent, relaxing bedtime routine can help you unwind after a long day. This can include taking a warm bath, reading a book, and/or doing light yoga before going to sleep.
- Shut down the tech devices: Blue light11 emitted from smartphones, laptops, and TVs can suppress melatonin production, an important hormone for promoting sleep.
- Be smart about nighttime snacking: Rather than eating a big meal just before bed if you’re hungry, opt for light, healthy snacks such as an apple or whole grain crackers.
Questions for Your Doctor
Could I have a sleep disorder?
Sleep disorders such as sleep apnea and insomnia can lead to poor sleep that could impact weight management.3, 9, 10 If you suspect weight gain is due to poor sleep, a doctor can help confirm or rule out a potentially contributing sleep disorder.
Learn more about sleep studies here.
Does sleep burn fat?
While sleep itself doesn’t burn fat, getting good, quality sleep can promote weight loss and reduced caloric intake.6
Are my sleep habits interfering with my weight control?
Getting inconsistent sleep can lead to habits that may cause weight gain, such as excessive nighttime snacking or not having enough energy the next day to exercise. 2
Are there sleep therapies you recommend?
Practicing good sleep hygiene can be a great way to get your sleep back on track. Alternatively, your doctor may suggest cognitive behavioral therapy (CBT), which has shown promising results for chronic insomnia12.
Should I undergo a sleep study?
A sleep study can help diagnose sleep disorders, including sleep apnea. Be sure to speak to a doctor if you think you may have a sleep disorder.
Learn more: Signs of Sleep Apnea
When is the best time for me to exercise?
According to research13, high-intensity exercise within two hours before bed can negatively impact sleep. Rather, your doctor could help guide you on the best exercise regimen to ensure a healthy weight and nighttime rest.
Frequently Asked Questions
How many hours of sleep do I need to lose weight?
Getting a full seven to nine hours of sleep per night can help reduce your risk of sleep loss-related weight gain.1
Can better sleep help me lose weight?
Getting good, consistent quality sleep can reduce how many calories you take in, which may help promote weight loss.6
Ashley Zlatopolsky
Content Writer
About Author
Ashley Zlatopolsky is a Detroit-based writer and editor who specializes in sleep content. She writes about sleep health, hygiene and products for Sleep Advisor, Mattress Clarity, Real Simple, Sleep.com and more.
Side Sleeper
- “What are sleep deprivation and deficiency?” National Heart, Lung, and Blood Institute. 2022.
- “Sleep”. Harvard T.H. Chan School of Public Health. Webpage accessed April 11, 2024.
- Papatriantafyllou, Evangelia., et al. “Sleep deprivation: Effects on weight loss and weight maintenance”. Nutrients. 2022.
- “Metabolism”. Cleveland Clinic. 2021.
- Kothari, Vallari, et al. “Sleep interventions and glucose metabolism: Systematic review and meta-analysis”. Sleep Medicine. 2021.
- “Getting more sleep reduces caloric intake, a game changer for weight loss programs”. University of Chicago Medicine. 2022.
- Liu, Shuailing., et al. “Sleep deprivation and central appetite regulation”. Nutrients. 2022.
- “The link between obesity and obstructive sleep apnea”. American Academy of Sleep Medicine. Webpage accessed April 11, 2024.
- “Sleep apnea”. Mayo Clinic. Last modified April 6, 2023.
- “What is insomnia?” National Heart, Lung, and Blood Institute. 2022.
- “Blue light has a dark side”. Harvard Health Publishing. 2020.
- Walker, Jamie., et al. “Cognitive Behavioral Therapy for Insomnia (CBT-I): A Primer”. National Library of Medicine. 2022.
- “Intense workouts before bedtime won’t guarantee a good night’s rest, new research shows”. Concordia Univeristy. 2021.