How Sleep Can Help Weight Loss

New "miracle" weight loss remedies seem to surface each week, but the answer might lie in the simple activity we spend a third of our lives doing: sleeping. Find out how bad quality sleep can hinder your weight loss efforts.

Updated: Wednesday 24 April 2024

sleep and weight loss

For many of us, shedding a few pounds has been on the to-do list for a while now, yet it’s an ongoing struggle. It seems simple for the most part: consume fewer calories than you expend, eat a fairly balanced diet and exercise regularly. But unless you’ve got the patience to consistently count every calorie you’re eating, and are disciplined enough to exercise as frequently as maybe is best, losing weight often feels like an uphill battle. Clinically proven weight loss medication such as Alli and Orlos are shown to be effective, but for the best results, it’s also worth assessing how well you’re sleeping. You may be surprised to learn that sleep has just as much of an influence on our weight and well-being as diet and exercise! Despite this, sleep is often a neglected factor of our busy lives, with half of UK adults admitting to not getting enough sleep, and a quarter managing no more than five hours per night[1]. Here in the UK, we average six hours of sleep per night, although the National Sleep Foundation recommends seven to nine hours of sleep is optimal[2].

This article uncovers the considerable impact sleep can have on your weight, suggesting methods to improve your shut-eye.

What’s the Link?

Sleep plays an undeniably important role in healthy bodily functioning and mental wellbeing. Epidemiological evidence suggests that whilst rates of obesity have been increasing over the past 50 years, our sleep duration and self-reported quality of sleep has decreased[3]. Multiple studies have indicated a likely causal relationship between poor sleep and higher rates of weight gain, with numerous explanations proving poignant. Research that has investigated sleep deficit demonstrates an increased likelihood of developing metabolic disorders, gaining weight, and an increased risk of other chronic health conditions. Whilst further research is needed to fully understand the intricate connection between sleep and weight, a number of theories provide convincing evidence.

How Sleep Affects your Weight


You’d be forgiven for thinking that succumbing to food cravings is ultimately just a mental weakness, something that fit and healthy people still experience but choose not to act upon. Far more than simply a mindset, evidence indicates that those getting plenty of sleep may not have nearly as big an appetite as those deprived of a full night’s sleep. The neurotransmitters ghrelin and leptin are key to dictating appetite: ghrelin stimulates the appetite, whilst leptin suppresses it. Throughout the day, our bodies produce these neurotransmitters in various quantities to signal when we ought to consume more calories. Sleep helps to sufficiently regulate these neurochemicals, with research finding higher levels of ghrelin and lower leptin levels in sleep-deprived individuals getting fewer than the recommended hours of sleep per night[4]. Therefore, if you struggle to get in seven to nine hours of sleep, you’re likely to have a larger appetite and not feel as satiated as healthy sleepers.

Food Choices

Irrespective of our altered levels of hunger-signalling hormones depending on sleep duration, we may be choosing to consume more calories following a bad night’s sleep. One study found that participants in a sleep-deprived test group were more likely to select snacks that contained 50% more calories than the group that had a full night’s sleep, as well as being drawn towards high carbohydrate foods. Additionally, the test group were less likely to be able to resist high calories snacks like ice cream and cookies, despite having eaten a large meal only two hours prior[5]. Similarly, another study found late-night snacking increased in those starved of a good night’s sleep[6]. The suggestion here is that the lack of a good night’s sleep is likely to affect our ability to make healthy choices the following day, making it that much harder to resist temptation and say no to calorie-dense foods, which contribute to weight gain. This is a particularly important factor in reducing obesity in children and adolescents, who may be less concerned with dieting, and where high-quality sleep is vital during this crucial stage of their development.

Metabolism and Insulin

When we don’t get enough sleep, we experience a spike in the stress hormone cortisol, which triggers the conservation of energy meaning we store more fat. One study found that when they decreased the sleep of their experimental group over a two week period, the weight they lost from fat reduced by 55%, even though their calorie intake didn’t change[7]. As well as increased hunger and a depletion of energy levels, their base metabolism declined, a greater proportion of the calories they were consuming were not being used for necessary bodily functions but instead were being stored as fat. With a lack of sleep, our body finds it more difficult to process insulin, the hormone needed to convert sugar, starches and other foods into energy. A reduction in insulin sensitivity means your body won’t be able to properly process fats from the bloodstream, again leading to more fat being stored.

Physical activity

Following a sleep-deprived night, we’re far less likely to engage in physical exercise the following day, due to feeling like we have less energy and a reduction in our motivation. Not only this, but being tired when engaging in sports becomes less safe, negatively affecting balance and ability to concentrate (especially key for activities such as weightlifting). Not only is exercise key to keeping us healthy and expending calories, but it helps speed up our metabolism, reducing the likelihood of excess calorie intake.

Tips for Quality Sleep To Aid Weight Loss

We’re all well aware of the importance of sleep, but it’s easy for our hectic schedules and the temptation of social media to throw a spanner in the works. Here are our top tips for getting a plentiful night’s sleep:

  • Make sure to exercise - getting regular exercise will improve the quality of your sleep, and is particularly good for circadian rhythm if it involves being out in natural light. Just over an hour of intense exercise per week, or two and a half hours of moderate-intensity exercise, will increase concentration and decrease how sleepy you are during the day, so when it comes to nighttime you will have a deeper and more refreshing sleep[8].
  • Maintain a regular sleep schedule - it may be tempting to cut corners during the week and try to make up for lost time sleeping during the weekend, but inconsistent sleeping and waking times can lead to reduced insulin sensitivity and changes in your metabolism, with higher blood sugar levels.
  • Sleep supplements - to relieve temporary insomnia and have a full night’s sleep, popular and affordable medication is widely available. Treatment such as Nytol and Sominex contain the same active ingredients in antihistamines that result in drowsiness, helping you to fall asleep quicker and enjoy a deeper sleep, reducing tiredness the following day.
  • Eliminate excess stress - although easier said than done, reducing your stress levels will likely help you in your weight loss attempts. High long-term cortisol levels have been linked to weight gain, and can be due to overeating as a coping mechanism for negative emotions, amongst other reasons[9]. Some methods of relieving stress include being more active, eating healthier, reducing smoking and drinking alcohol, meditating, connecting with others, and exploring a creative outlet.
  • Try waking up earlier - being an “early bird” may be more likely to maintain weight loss than “night owls”, in part due to those with later bedtimes consuming more calories on average[10]. There’s also proven health and mental wellbeing benefits of keeping your sleep schedule more closely in line with natural day and night hours, so you can get out and about in daylight as much as possible.
  • Sleep in a dark room - being exposed to artificial light whilst sleeping, such as a TV or lamp, has been associated with an increased risk of gaining weight and being obese. Similarly, artificial light from a phone or laptop signals our brain to stay awake, confusing our internal body clock and reducing the quality of sleep.
  • Keep it cool in the bedroom - temperature contributes to the body’s maintenance of circadian rhythm. If your bedroom is too warm this can interfere with our ability to thermoregulate, whilst also causing fatigue. A body temperature that’s too high when going to sleep will result in difficulty falling asleep, and reduce the time spent in the key sleep stages such as slow-wave sleep.
  • Take Vitamin D supplements - a lack of enough Vitamin D, especially common in people of colour, and in all races during low light months, is linked to a higher risk of sleep disturbances, poorer sleep quality and reduced sleep duration[11].
Toby Watson

Written by: Toby Watson

Pharmica Medical Writer

Toby (BSc) is an experienced medical writer, producing educational articles on many areas of health including sexual health, fitness, nutrition and mental health.

He particularly enjoys debunking misconceptions around heath conditions and their treatments, researching each topic in detail and writing easily-accessible content.

Find out more about how we ensure the accuracy of our content with our content guidelines.

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