NCPA - National Center for Policy Analysis


December 3, 2004

The less you sleep, the more likely you are to become obese, according to a study by researchers at Columbia University's Mailman School of Public Health and the Obesity Research Center.

The researchers demonstrated a clear link between the risk of being obese and the number of hours of sleep each night, even after controlling for depression, physical activity, alcohol consumption, ethnicity, level of education, age and gender. The study was an analysis of data taken from the National Health and Nutrition Examination Survey I (NHANES I).

Specifically, the study found:

  • Subjects between the ages of 32 and 59 who slept four hours or less per night were 73 percent more likely to be obese than those who slept between seven and nine hours each night.
  • People who got only five hours of sleep had a 50 percent higher risk than those who were getting a full night's rest.
  • Those who got six hours of sleep were just 23 percent more likely to be substantially overweight.

The results are somewhat counterintuitive, since people who sleep less are naturally burning more calories, says lead researcher James Gangwisch.

"It has more to do with what happens to your body when you deprive it of sleep as opposed to the amount of physical activity that you get," says Gangwisch.

Other studies have shown that leptin levels decrease and grehlin levels increase in people who are sleep-deprived, leading to increased appetite and consumption.

Source: "Lack of Sleep May Lead to Excess Weight - Study Finds Link Between Hours of Sleep and Risk of Obesity," North American Association for the Study of Obesity, November 16, 2004.


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