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Can Sleep Help you Lose Weight?

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For all of our efforts training hard and watching what we eat, we sometimes neglect the simplest of lifestyle hacks that can boost our fat loss gains.

Research shows that we spend far less time in slumber land than our ancestors did – and this is having a negative effect on not just our health, but also our weight.

In this article we’ll take a look at the importance of a good night’s rest and whether or not it can help you achieve your weight loss goals.

  • The importance of sleep
  • What does the science say?

The Importance of Sleep

Sleep is an essential physiological process – and whilst scientists can’t actually agree on the exact reason why we need enough time in the sack, what they do all agree on is that it is paramount for health and well-being. There are also a number of side effects if you don’t. Here is a breakdown of what to expect if you’re sleep suffers:

Reduced Immune Function

Good quality rest boosts your immune system – those that restrict their sleep are more likely to get common colds and niggling illnesses. One study [1] found that staying up until 3am for just one night reduced a number of white blood cell counts in healthy volunteers, and another study [2] found those who achieve less than 7 hours rest per night are nearly 3 times more likely to develop a cold than those who get 8 hours.

Decreased Athletic performance

There’s nothing worse than trying to get through a tough gym session when you’re tired. Sleep restricted athletes have lower concentration levels, elevated heart rate, lower mood and decreased productivity. On the other end of the scale, basketball players who achieved 10 hours or more per night improved their shooting accuracy by 9%, as well as their reaction time and sprint ability [3].

Increased long-term Health Risk

If you suffer from poor shut-eye on a regular basis you can expect that your risk of long-term illness can increase dramatically. Your insulin sensitivity and management of blood sugar decreases and as such your risk of type 2 diabetes increases – only achieving 4 hours per night for any longer than a week can even put you into a pre-diabetic state [4].

Additionally, short sleep periods can increase your risk of coronary heart disease or stroke as well as greater risk of early death [5].

Decreased Emotional Well-being

Limiting slumber duration can affect not just your body but also your mind as well, with poor sleep being strongly linked to depression. According to research published in the Journal of Clinical Psychiatry [6], of all mental disorders associated with insomnia, depression is the most common. 

As many as 90% of people with depression complain about poor quality shut-eye and 59% reported that it significantly affected their quality of life [7].


Key Point: Poor-quality slumber can decrease your immune system and increase your risk of both short- and long-term illness.

The science – can sleep help you lose weight?

#Study 1: Patel et al [8]

This study, published in the journal Obesity, used a systematic review approach to analyzing the effects of sleep on weight gain.

After looking over 36 publications, the authors concluded that 17 of 23 studies supported an association between short periods of sleep duration and increased weight. However, this relationship appeared to wane with age suggesting that as we get older, getting your head down becomes less important.

#Study 2: Capuccio et al [9]

This study investigated sleep duration and its association with the development of obesity from childhood to adulthood.

In a massive study of 30,002 children and 604,509 adults, the authors analysed shut-eye behavior and weight gain and reported that children were 89% more likely to become obese if they didn’t get their head down for long enough periods, and 55% in adults. 

#Study 3: Taheri et al [10]

A study by Taheri et al suggested that sleep may be an important regulator of metabolism and weight and that links between the quality of your night’s rest and your body mass index (BMI) strongly exist.

The researcher suggested that two hormones in particular can be affected if you don’t get enough shut-eye – leptin and ghrelin. 

Leptin is released from your fat cells and suppresses your appetite – when leptin levels increase, you feel fuller and content. Ghrelin however is released from the stomach and stimulates appetite – and when this hormone increases you feel hungrier.  

This study found that in a group of 1,024 volunteers, leptin levels were 15.5% lower in those that only managed 5 hours rest instead of 8 hours. Ghrelin was 14.9% higher. This means that the sleep-restricted group were more likely to have an increased appetite – and this is more than likely the contributing factor in the groups’ weight gain.

#Study 4: Gluck et al [11]

Lastly, this study published in the American Journal of Clinical Nutrition reported that ‘night time eaters’ – those who were likely to eat between 11pm and 5am, were likely to be over 6kg heavier than their non-eating counterparts. They regularly ate on average 690kcal between these hours, and were more likely to choose foods that were high in carbohydrates and sugar.


Key Point: Research shows that sleep is an important regulator of metabolism.

Summary – the sleep and weight loss connection

Sleep is an essential physiological process for maintaining good health. The consequences of limited slumber time include a decreased immune system, increased risk of long-term illness and ultimately early death. Your cognitive ability as well as your athletic performance suffer as well, as your duration decreases.

Research shows that restricted rest times can increase your appetite which can contribute to weight gain, and that those who achieve good-quality and quantity of shut-eye are less likely to be overweight or obese.


  1. Irwin, M et al. Partial night sleep deprivation reduces natural killer and cellular immune responses in humans. FASEB J. 1996; 10(5): 643-53
  2. Cohen, S et al. Sleep habits and susceptibility to the common cold. Arch Intern Med. 2009 12; 169(1): 62-7
  3. Mah, CD et al. The Effects of Sleep Extension on the Athletic Performance of Collegiate Basketball Players. Sleep. 2011; 34(7): 2011
  4. Spielgel, K et al. Impact of sleep debt on metabolic and endocrine function. Lancet. 1999 23; 354(9188): 1435-9
  5. Cappuccio, FP et al. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010; 33(5): 585-92
  6. Tsuno, N et al. Sleep and depression. J Clin Psychiatry. 2005; 66(10): 1254-69.
  7. Nutt, D et al. Sleep disorders as core symptoms of depression. Dialogues Clin Neurosci. 2008; 10(3): 329–336
  8. Patel, SR et al. Short Sleep Duration and Weight Gain: A Systematic Review. Obesity. 2008; 16(3): 643–653
  9. Cappuccio, FP et al. Meta-Analysis of Short Sleep Duration and Obesity in Children and Adults. Sleep. 2008; 31(5): 619–626
  10. Taheri, S et al. Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index. PLoS Med. 2004; 1(3): e62
  11. Gluck, ME et al. Nighttime eating: commonly observed and related to weight gain in an inpatient food intake study. Am J Clin Nutr. 2008; 88(4): 900-905