Women who sleep 5 hours or less per night weigh more on average than those who sleep 7 hours, according to a study presented at the American Thoracic Society International Conference on May 23rd.

The study found that women who slept for 5 hours per night were 32% more likely to experience major weight gain (defined as an increase of 33 pounds or more) and 15% more likely to become obese over the course of the 16-year study compared with women who slept 7 hours. Women who slept for 6 hours were 12% more likely to have major weight gain and 6% more likely to become obese compared with women who slept 7 hours a night.

On average, women who slept 5 hours or less per night weighed 5.4 pounds more at the beginning of the study than those sleeping 7 hours and gained an additional 1.6 pounds more over the next 10 years.

“That may not sound like much, but it is an average amount—some women gained much more than that, and even a small difference in weight can increase a person’s risk of health problems such as diabetes and hypertension,” said lead researcher Sanjay Patel, MD, assistant professor of medicine at Case Western Reserve University in Cleveland.

In total, ATS drew more than 15,000 attendees and featured more than 5,000 research presentations. For more information about the studies presented at ATS 2006, please visit the ATS online at www.thoracic.org.