Sleep and Obesity – A New Link

We all know the benefits of getting adequate sleep. Two recent studies points out the effects of sleep patterns on body weight.

In one trial, children who slept less than 9 hours per night were three times as likely to be overweight, independent of their level of physical activity. Children with shorter sleep duration were also more likely to be emotionally labile than children who slept longer.

A second study looked at sleep patterns in adult patients with chronic medical conditions. Those who got less than 7 hours of sleep per night were more likely to be obese than those who slept more. In women, sleep that was too short or too long were both linked to obesity.

It is hard to say exactly what the connection between sleep and body weight is. Perhaps poor sleep leads to dysregulation of hunger or decreased levels of physical activity during the day. On the other hand, decreased sleep may be the result of weight gain, causing individuals difficulty in sustaining normal sleep patterns. It is known that overweight adults are more likely to suffer from obstructive sleep apnea, which can cause severe disturbances that prevent restful sleep.

Sleep is a key factor in allowing the brain and body to function, but how it actually benefits us is still poorly understood. Whatever the mechanism, it is clear that even slight sleep deprivation impairs our cognitive and physical functioning. Sleep is necessary for our bodies to functional optimally. Mental function declines progressively as sleep deprivation continues, and emotional lability likewise increases with a lack of rest.

Children require more sleep than adults because they are growing so rapidly. It is recommend that pre-school children get 11-13 hours of sleep and older children get 10-11 hours per night. Likewise, patients with chronic disease face metabolic and physical challenges that require more energy just to function normally; adults need at least 8 hours of sleep.

But even healthy adults are commonly sleep deprived, increasing their risk of a myriad of health problems including infection, elevated stress, poor cognitive function and depression, just to name a few. Despite our hectic lifestyles, its important to take the initiative and allow your body the rest it requires.


Nixon GM, Thompson JMD, Han DY, Becroft DM, Clark PM, Robinson E, Waldie KE, Wild CJ, Black PN, Mitchell EA. Short sleep duration in middle childhood: risk factors and consequences. Sleep 2008;31(1):71-8.

Buscemi D, Kumar A, Nugent R, Nugent K. Short Sleep Times Predict Obesity in Internal Medicine Clinic Patients. Journal of Clinical Sleep Medicine 2007; 3(7): 681-8.

Lindsey Kay, MD

Lindsey Kay, MD, is a medical doctor with training in pathology, and an avid writer. During his training, he worked on pre-clinical and clinical trials in a variety of laboratories related to alcohol effects on the brain, cancer diagnosis, and alternative medicine.
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