Study links more sleep to lower BMI in adolescents

Philadelphia – Increasing nightly sleep from 8 to 10 hours for adolescents may help reduce obesity, finds a new study from the University of Pennsylvania.

Researchers tracked almost 1,400 Philadelphia-area high school students from freshman through senior year. Every six months, the students reported their sleep patterns and were measured for height, weight and body mass index. Each extra hour students slept was associated with a decrease in BMI, especially for students with higher BMIs, according to the study abstract.

Researchers estimated that increasing sleep time would result in 500,000 fewer overweight adolescents.

The relationship between sleep and BMI existed even when adjustments were made for spending time in front of a computer or TV. This suggests adolescents could see a decrease in weight even if they do not meet physical activity guidelines, researchers said in a press release.

Researchers also recommended that high schools push back daily start times, as efforts to educate adolescents on sleep benefits have had little impact.

The study was published online April 8 in the journal Pediatrics.