The Effect of Sleep on Weight Loss: How Lack of Sleep Affects Your Weight

By Hannah Kemish | Tuesday 18th June 2019

Last updated on Tuesday 28th July 2020

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Obesity is a major public health problem. It’s become a global epidemic and is costing the NHS billions (Fenton 2017). But did you know sleep is a contributor? This post will discuss the effect of sleep on weight loss. We will also look into some of the other reasons why sleep is so important.

The Effect of Sleep on Weight Loss

Sleep ‘is a restorative process of the brain, by the brain, and for the brain’ (Adam, 1980). But it also plays a huge part in the health of the whole body. It takes up one-third of a humans life.

The effect of sleep on weight loss

For those looking to lose weight, it’s common knowledge to exercise and eat less. This induces weight loss, as well as reducing the health risks associated with being overweight (Chaput and Tremblay, 2012). There is a lot of research that highlights the effect of sleep on weight loss. They show that sleep deprivation has an impact on the current obesity epidemic (Cappuccio et al., 2008).

Sleep Deprivation and Healthy Sleep

Sleep deprivation is when a person’s natural sleep need is not met. It is far too common in modern societies. People who have less than 7 hours sleep a night are considered sleep deprived. Work and leisure events are becoming more popular in the evening and night-time. These all lead to a loss of hours available for sleep, which has a major impact on sleep time. Less time spent in the dark and more artificial light often results in later bedtimes.

Good sleep doesn’t just require time. Quality and regularity are also key. Alongside this, there should be no evidence of sleep disturbances or sleep disorders (Watson 2015).

The Effect of Sleep on Weight Loss

Many studies highlight how vital sleep is to your health. But newer research focuses specifically on weight loss.

For example, there is evidence that lack of sleep enhances areas of the brain associated with the drive to consume food. The effect of sleep on weight loss here is to moderate how much we eat. Without enough sleep, it could be very likely to consume more food (Chaput and Tremblay, 2012).

sleep affects hunger levels

Sleep plays a role in hunger and the body’s tolerance to glucose. Sleep loss damages metabolism and neuroendocrine function. This results in the body being less able to tolerate sugar. (Beccuti and Pannain, 2011). This highlights a clear effect of sleep on weight loss. Sleep deprivation has also been shown to alter areas of our bodies that control the appetite. Because of this, sleep has an effect on weight loss. It even influences how well dietary interventions work (Chaput and Tremblay, 2012).

Sleep, Leptin and Energy Balance

Sleep loss could affect energy balance. When the body is deprived of sleep, it lowers the amount of energy we burn. This is both during exercise, and outside of the gym. The hormone leptin, associated with sleep, increases energy expenditure (Scarpace et al., 1997). Therefore, the change in leptin levels caused by lack of sleep reduces how much energy we burn.

Leptin is a hormone linked to sleep. When it comes to the effect of sleep on weight loss, this hormone is key. Studies link leptin to fatty tissue stored in the body. For example, leptin levels are higher in the obese (Considine et al., 1996). When we are sleep deprived, leptin levels rise.

How Much Sleep Do We Need?

The effect of sleep on weight loss mostly comes down to how much sleep we get. Studies show a correlation between short habitual sleep duration and a higher body mass index (BMI).

Studies show sleep affects the brain and hunger levels

It’s recommended that we should sleep for at least 7-9 hours per night. We should get these hours regularly. Doing this promotes good health, and has a positive impact on weight. Sleeping less than this can damage health. Issues include weight gain and obesity, diabetes, hypertension, and heart disease. Alongside this, lack of sleep contributes to stroke, depression and an increased risk of death.

There are situations where we need more than 9 hours regularly. This is the case for young adults and people recovering from illness or sleep deprivation. It is important to note that people may have variability in sleep needs. This is influenced by genetics, as well as behavioural and medical factors.

How To Improve Your Sleep

If you suffer from sleep deprivation or a poor sleeping pattern, it might be time to make some changes. Now you understand the effect of sleep on weight loss, this is especially true if you want to lose weight.

avoid screens and devices at bedtime

Some of the following changes may work for you:

  • Keep a consistent sleep pattern (shift workers may struggle a little more with this). Get up at the same time every day, even at the weekend and during holidays.
  • Set a bedtime that will allow you 7 hours of sleep at least.
  • If you don’t fall asleep after 20 minutes, get out of bed.
  • Try to establish a relaxing bedtime routine.
  • Avoid using devices like laptops and smartphones 30 minutes before bedtime.
  • Avoid bright lights in the evening.
  • Use your bed only for sleep.
  • Make your bedroom quiet and relaxing, and keep it at a comfortable temperature.
  • Avoid eating a large meal before bedtime.
  • Don’t drink caffeine in the late afternoon and evening.
  • Avoid alcohol before bedtime.
  • Reduce fluid intake before bedtime.


Alongside the well-known method of moving more and eating less, there is a noticeable effect of sleep on weight loss. It is sometimes not as simple as “eat less and move more”. Sleep deprivation is on the rise. And along with this, leptin levels are likely to rise, as well as other hormones. In turn, these decrease energy expenditure, increase the likelihood of making the wrong food choices, and negatively impact appetite control.

A good fitness regime goes a long way when it comes to helping you lose weight. Now that you know about the effect of sleep on weight loss, read about how to find the perfect workout plan here. Struggling with motivation? This post could help. Or, if you find it tricky to stick to a plan, did you know that tracking makes a huge difference? Read some of the best fitness and nutrition tracking strategies here.

Hannah Kemish


Strength and Conditioning Coach, MSc, BSc (Hons)

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