Les liens entre le manque de sommeil, l’augmentation du cortisol et la prise de poids

thesleep is essential for good health. It allows the body to rest and the brain to process the information received during the day. Sleep is regulated by one of the body's circadian clocks, mechanisms that regulate daily processes.

Hormones and sleep

Several hormones and neurotransmitters regulate sleep. For example, adenosine is a neurotransmitter that in high concentrations promotes sleep. There is also melatonin, a hormone produced by the brain when it is dark and which tells the body that it is time to sleep. However, light, solar or artificial, inhibits the production of melatonin and increases the production of cortisol, a hormone that promotes wakefulness and which is also secreted in response tostress.

Lack of sleep

Lack of sleep can lead to difficulty concentrating and thinking. However, in the long term, lack of sleep can increase the risk of various diseases, such as obesity, diabetes, cardiovascular disease and depression.

Lack of sleep and obesity

Several studies show that lack of regular sleep (regularly sleeping less than 7 hours a night) is a risk factor for obesity. This could be caused, in part, by an imbalance in the hormones that regulate hunger and satiety. Indeed, with lack of sleep, levels of ghrelin, the hunger hormone, increase and levels of leptin, the satiety hormone, drop. In addition, studies observe that lack of sleep can lead to an increase in cortisol levels, a hormone that can increase appetite, especially for foods high in sugars, fats and calories. Therefore, lack of regular sleep could cause an increase in calorie consumption and promote weight gain.

The consequences of chronic stress

Just like lack of regular sleep, chronic stress can also have health and weight consequences. (See the article:Is Stress Harming Your Weight Loss?) According to an article by Harvard University Medical School, chronic stress has adverse health consequences. Some research suggests that it contributes to the development of high blood pressure, the formation of artery-clogging deposits, and causes brain changes that can contribute to anxiety, depression, and addictions. Other research indicates that it may also contribute to obesity both directly (eg, by making people eat more) and indirectly (eg, by decreasing sleep and exercise). (See the article:The link between food and emotions)

As mentioned earlier, cortisol is a hormone secreted in response to stress. However, at high levels, this hormone can contribute to weight gain and fat accumulation, as it can increase appetite and the storage of excess nutrients as fat.

The recommendations

The Public Health Agency of Canada recommends adults ages 18 to 64 get 7 to 9 hours of sleep per night and adults 65 and older get 7 to 8 hours of sleep per night.

Some tips for better sleep hygiene and to promote stress management

  • Go to bed and get up at regular times.
  • Have daily physical activity. (See the article:Fight depression, anxiety and stress through sport?)
  • Avoid heavy meals, caffeine, alcohol and nicotine before going to bed.
  • Avoid using electronic devices before going to bed, especially those that emit blue light (e.g. cell phone, tablet, television).
  • Create a quiet, calm and comfortable sleeping environment.
  • Use relaxation techniques (e.g. breathing exercises, meditation, etc.).
  • Limit naps to 30 minutes.


  1. https://www.hsph.harvard.edu/nutritionsource/sleep/
  2. https://www.biron.com/fr/centre-du-savoir/parole-de-specialiste/impact-lack-sleep/
  3. https://www.canada.ca/en/public-health/services/publications/healthy-living/adult-canadians-sleep-enough-infographic.html
  4. https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response#:~:text=Elevated%20cortisol%20levels%20create%20physiological,tissue%20and%20to%20weight%20gain.
  5. https://www.hsph.harvard.edu/nutritionsource/stress-and-health/


Photo credit: Photo byMegan te Boekhorst weUnsplash  


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