Weight Gain and Sleep
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I have received many questions about the relationship between sleep and weight gain and if lack of sleep leads to weight gain.

Medical studies have traditionally shown that lack of sleep may be one of the reasons that lead to obesity. While we know that people do not get adequate sleep due to stress and the pressures of a fast-paced life, studies have revealed that sleeping very late is a prime reason for reduced sleep. Moreover, it suggests that the lack of sleep has negative effects on health in general.

It has been observed that in the recent years that the rate of obesity in the Middle East region has steadily increased. This is attributed mainly to the several lifestyle changes that lead to faulty eating habits and the drastic reduction in physically demanding activities.

We know that obesity leads to various health problems. Hence, keeping it under check and trying to limit its spread should be one of the most important priorities of the various health authorities.

Can lack of sleep qualify as a lifestyle related change that can lead to obesity? Sleep Study on College Student

A few months back, a research was carried out by a group of scientists from the University of London. They evaluated a sample size of 17,000 college students (within the age group of 17 to 30 years, living in 24 countries), for sleep patterns and general health.

It was noted that 63% of the respondents slept for 7 to 8 hours a day and 21% slept for less than 6 hours while only 16% slept more than 8 hours. It was also found that those who slept for less than 6 hours were more prone health problems than the others.

Therefore, there is evidence to suggest that there is a relation between the duration of sleep and health in general and, specifically, a relation between short hours of sleep and obesity.

Yet another study carried out on a sample size of 100 people in the United States of America, and published in Annals of Internal Medicine, has also shown a relation between lack of sleep and weight gain.

It is known that a relation exists between sleep and two of the most important hormones that control appetite and eating, Leptin and Ghrelin respectively. An increase in Leptin leads to a loss of appetite, while an increase in Ghrelin results in hunger and an increased appetite. Now, reduced sleep is known to decrease the secretion of Leptin that in turn makes one feel excessively full, while the increase in Ghrelin causes hunger. In other words, lack of sleep may directly lead to weight gain on a physiology level.

The results of field research carried out on the students of a high school in America, and published in the Sleep and Breathing magazine, has shown that 90% of the high school students sleep less than 8 hours per day of which 19% sleep for less than 6 hour per day. The survey found that 20% of the high school students were overweight (as per international standards).

The results of the study also concluded that there is a strong relation between increase in drinking coffee on the one hand and lack of sleep on the other. The researchers have found that:

No of Hours of Sleep

Likelihood of Obesity

Less than 5 hours

8.5 x

5 to 7 hours


7 to 8 hours


More than 8 hours



Another lifestyle attribute accompanied with lack of sleep is improper eating habits. Those who stay up late usually do so to watch TV or to complete official work. These activities are usually accompanied with munching on unhealthy junk foods that often contains high calories, which ultimately lead to weight gain.

Sleep and Obesity

Hence, one can safely conclude that there is a relationship between lack of sleep and weight gain. While ongoing scientific research tries to discover the reason for this relation between lack of sleep and weight loss, if you want an ideal weight I suggest you gain adequate sleep!


Ahmed BaHammam, FACP, FCCP
Professor of Medicine
Director, University Sleep Disorders Center
College ofMedicine, King Saud University