Longer Sleep Duration Inhibits Genetic Factors Promoting Weight Gain

A new study examining the relationship between sleep duration and body mass index (BMI), suggests that getting plenty of sleep each night may help to suppress certain genetic factors that promote weight gain. Nathaniel Watson, of the University of Washington, and colleagues collected data on height, weight, and sleep habits from 1,088 pairs of twins. Results showed that genetic influences accounted for 70% of differences in BMI in twins that slept for seven hours or less each night, compared with just 32% in those that slept for nine hours or more each night. Furthermore, shorter sleep duration was associated with increased BMI, whilst longer sleep duration was associated with decreased BMI. The researchers concluded: “Shorter sleep duration is associated with increased BMI and increased genetic influences on BMI, suggesting that shorter sleep duration increases expression of genetic risks for high body weight. At the same time, longer sleep duration may suppress genetic influences on body weight.”