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Specialist Advice — 15 minutes

The impact of sleep deprivation on weight

Dr Pierre Mayer
Dr Pierre Mayer
Respirologist - Medical Director - Sleep Care

It may seem obvious, but sleep is essential to function well during the waking hours. It’s not simply because of the fatigue felt if you don’t get enough sleep. The lack of sleep upsets the hormonal balance in a way that can have concrete effects on the body.

Over the past 50 years, human beings have become increasingly overweight and been getting less and less sleep. The percentage of individuals who are obese has risen from 10% to 25%, while the amount of sleep people are getting has fallen by more than two and a half hours on average. According to several researchers, sleep deprivation is the main factor behind the current obesity epidemic [1, 2]. Weight gain along with an increase in waist size, body fat and caloric intake have been associated with insufficient and poor-quality sleep [4, 5, 6, 7].

How does the lack of sleep contribute to weight gain?

The lack of sleep is believed to influence our hormones and behaviour in the following ways:

  • Imbalance of the hormones that regulate hunger
  • Consumption of food to reduce fatigue
  • More opportunities to eat
  • More sedentary lifestyle
  • Lower blood sugar levels

Researchers in Quebec analyzed the risk of obesity in 283 subjects over a six-year period. They found that sleep deprivation alone triples the risk of obesity, an increase comparable to that produced by inactivity and a fat-rich diet combined [2].

Imbalance of hormones that regulate hunger

Hunger and satiety are both governed by hormones. Several studies have suggested that a lack of sleep causes an increase in ghrelin, the hormone that triggers hunger, as well as a decrease in leptin, the hormone that inhibits it [8]. In addition, a lack of sleep leads to an increase in the level of cortisol, the stress hormone, which tends to increase the appetite, especially the craving for sugar. Therefore, people may be inclined to consume more calories when they have not had enough sleep [8, 9]. A meta-analysis conducted in 2017 revealed that, on average, a sleep-deprived person consumes 400 more calories than someone who is well rested [4]. At such a rate, the excess caloric intake would translate into an estimated weight gain of close to 18 kilograms (40 pounds) per year.

Consumption of food to reduce fatigue

Studies of the diets of sleep-deprived people reveal that they tend to favour foods high in fat over those high in protein [6]. This is not surprising when we consider that eating stimulates the secretion of orexin, the hormone that reduces fatigue. Orexin is associated with reward-driven eating behaviour in which food is not eaten to satisfy hunger but to satisfy an emotional or psychological need. This is believed to result in poor impulse control, which increases the tendency to consume more calories than necessary [8]. In children, sleep deprivation is associated with the increased consumption of unhealthy foods and soft drinks at the expense of fruits and vegetables [11].

More opportunities to eat

Increased wakefulness due to short periods of sleep increases the opportunities to eat and promotes the tendency to snack. Unfortunately, the calories burned during the waking hours do not compensate for the calories ingested due to fatigue and changes in the metabolism.

More sedentary lifestyle

The fatigue associated with a lack of sleep may contribute to reduced physical activity and an increase in sedentary behaviour such as watching television. However, studies have not been able to demonstrate these factors with any consistency [8].

Lower blood sugar levels

Long hours of wakefulness are associated with a slight drop in blood sugar, which in turn stimulates the secretion of ghrelin, the hormone that triggers hunger.

The case of sleep apnea

Beware of preconceived notions: everyone can be affected by sleep apnea, regardless of their weight. However, obesity remains the main risk factor. The distribution of fat in the neck, pharynx and stomach (abdomen) can block the passage of air in the upper respiratory tract (nose, throat) during the night and cause respiratory arrest, or sleep apnea. Fatigue and the resulting metabolic disturbances are likely to maintain the vicious circle of sleep deprivation and weight gain.

The transition to a healthy weight

Making changes to your lifestyle is the best way to regain a healthy body weight. Fortunately, since the quality of sleep generally improves when sleep apnea is treated properly, it becomes easier to make the adjustments.

Read more: The Challenges of Healthy nutrition

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  1. VanCauter, E. (2008), “Metabolic Consequences of Sleep and Sleep Loss,” Sleep Medecine, vol. 9, suppl. 1
  2. Chaput, J.-P. (2010), “Risk Factors for Adult Overweight and Obesity: The Importance of Looking Beyong the ‘Big Two’,” Obes Facts, vol. 3, p. 320-327
  3. Povitz, M. et al. (2017), “Wait Times from Diagnosis to Treatment of Obstructive Sleep Apnea in Ontario: A Population-Based Cohort Study,” Sleep and Health Policy, C80-D, A6526-A6526
  4. Hale, L. (2012), “Longitudinal associations between sleep duration and subsequent weight gain: a systematic review,” Sleep Medicine Reviews, vol. 16, no. 3, p. 231-241
  5. Després, J. P., Bouchard, C. and Tremblay, A., (2008), “The association between sleep duration and weight gain in adults: a 6-year prospective study from the Quebec Family Study,” International Journal of Obesity, 32S35-S35
  6. Al Khatib, H. K., Darzi, J., Pot, G.K. (2017), “The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis,” European Journal of Clinical Nutrition, 2017, vol. 71, no. 5, p. 614-624
  7. Fatima, Y., Doi, S. and Mamun, A. (2016), “Sleep quality and obesity in young subjects: A meta-analysis,” Obesity Reviews, vol. 17, no. 11, p. 1154-1166. doi:10.1111/obr.12444
  8. Hartman, Terryl J. et al. (2012), “Partial sleep deprivation and energy balance in adults: an emerging issue for consideration by dietetics practitioners,” Journal of the Academy of Nutrition and Dietetics, vol. 112, no. 11, p. 1785-1797
  9. Shechter, A. (2017), “Obstructive sleep apnea and energy balance regulation: A systematic review,” Sleep Medicine Reviews, vol. 34, p. 59-69
  10. Stice, E., Burger, K. S. and Yokum, S. (2013), “Relative ability of fat and sugar tastes to activate reward, gustatory, and somatosensory regions,” The American Journal of Clinical Nutrition, vol. 98, no. 6, p. 1377–1384. doi:10.3945/ajcn.113.069443
  11. Córdova, F. V., Barja, S. and Brockmann, P.E. (2018), “Consequences of short sleep duration on the dietary intake in children: A systematic review and metanalysis,” Sleep Medicine Reviews, vol. 42, p. 68-84
  12. Basoglu, O. et al. (2018), “Change in weight and central obesity by positive airway pressure treatment in obstructive sleep apnea patients: Longitudinal data from the ESADA cohort,” Journal of Sleep Research, vol. 27, no. 6
Dr Pierre Mayer
Dr Pierre Mayer
Respirologist - Medical Director - Sleep Care
Dr. Mayer, associate clinical professor and director of the sleep clinic at the Centre hospitalier de l’Université de Montréal (CHUM), is a pulmonologist with post-doctoral training in sleep disorders from the Université Joseph Fourier in Grenoble, France, and McGill University in Montreal. He has been the medical director for Biron – Sleep Care since 1998.