Wake-up call: Research shows too little sleep can be associated with increased body weight.

A good night’s sleep is restorative for both the brain and the body and it may also be a factor in preventing obesity.

An increasing number of studies show that too little sleep can result in too much weight gain. Specifically, those who regularly get less than seven hours of sleep a night are at a higher risk of becoming overweight or obese.

The Nurses’ Health Study, the most significant study on sleep habits and weight, which followed 68,000 middle-aged American women for up to 16 years, found that compared to women who slept seven hours a night, women who slept five hours or less were 15 percent more likely to become obese over the course of the study.

Even just a slight sleep deprivation can have a big impact on weight. In a JAMA Internal Medicine report, researchers who used Fitbit wearable technology to collect sleep data from more than 120,000 people over a two-year period found that those who are obese (with a BMI of 30 or above) only slept about 15 minutes less than their less weighty counterparts. 

Childhood sleep habits can also have a long-term impact on weight. Children who slept less than 10.5 hours a night at age three had a 45% higher risk of becoming obese by age 7 when compared to children who slept more than 12 hours a night, according to a British study of 8,000 children followed from birth. 

Lack of sleep may be a major contributor to the obesity epidemic, which parallels the trend of reduced sleep duration. Rates of obesity have doubled since 1980 (36.5% of Americans are now classified as obese) while some 40% of American adults do not get enough sleep each night—in 1998 35% of adults got 8 hours of sleep a night; today the average is 6.8 hours a night.

This lack of sufficient shut-eye can lead to weight gain for several reasons. Sleep deprivation affects the hunger hormone called ghrelin, which stimulates appetite, as well as another hormone, leptin, which suppresses appetite. Also, staying up late means there are more waking hours in which to eat. And sleep deprivation can increase tiredness which may decrease the motivation to exercise.  

A healthy sleep schedule not only helps maintain a healthy weight but also boosts energy and mood. The ideal sleeping time for most people is between 7 to 9 hours. There are a number of things that can improve sleep quality, including going to sleep and waking up around the same time every day, limiting caffeine later in the day, moving electronic devices to another room and doing something relaxing before bedtime, such as taking a bath or listening to a guided meditation.

It’s ironic that while sleep may be the world’s most sedentary activity, it’s also one that may help prevent weight gain. Altering your sleep habits, even just a little, can have a big impact on your overall health and wellbeing.