Increased sleep could reduce rate of adolescent obesity

Increasing the number of hours of sleep adolescents get each night may reduce the prevalence of adolescent obesity, according to a new study by researchers from the Perelman School of Medicine at the University of Pennsylvania. Results of the study show that fewer hours of sleep is associated with greater increases in adolescent body mass index (BMI) for participants between 14 and 18-years-old. The findings suggest that increasing sleep duration to 10 hours per day, especially for those in the upper half of the BMI distribution, could help to reduce the prevalence of adolescent obesity. Full results of the study are available online in the latest issue of Pediatrics.

Previous studies have shown that a correlation exists between and obesity, but until now few have been able to rule out other variables such as time spent and being physically active. The new study observed over 1,000 Philadelphia-area from their freshmen through senior high school years. At six month intervals, were asked to report their . At the same intervals heights and weights were reported and BMIs were calculated. Study authors suggest the results could have far-reaching implications and aid in reducing the high levels of in the United States.

"The psychosocial and physical consequences of adolescent obesity are well documented, yet the rate has more than tripled over the last four decades," says lead author Jonathan A. Mitchell, PhD, in the Center for and Biostatistics at the Penn Medicine. "What we found in following these adolescents is that each additional hour of sleep was associated with a reduced BMI for all participants, but the reduction was greater for those with higher BMIs. The study is further evidence to support that getting more sleep each night has substantial health benefits during this crucial developmental period."

Overall, researchers noted the strength of the association between sleep and BMI was weaker at the lower tail of the BMI distribution, compared to the upper tail. For example, each additional hour of sleep was associated with only a slight reduction in BMI (0.07 kg/m2) at the 10th BMI percentile. In comparison, at the 50th percentile a higher reduction in BMI was observed (0.17 kg/m2), and at the 90th percentile an even greater reduction in BMI was observed (0.28 kg/m2). Importantly, the relationship between sleep duration and BMI remained after adjusting for time spent in front of computer and television screens and being physically activity, leading to the conclusion that more sleep could contribute to the prevention of adolescent obesity, even if national screen time and physical activity guidelines are met.

Based on the results, the authors suggest that increasing sleep from 8 to 10 hours per day at age 18 could result in a 4 percent reduction in the number of adolescents with a BMI above 25 kg/m2. At the current population level, a 4 percent reduction would translate to roughly 500,000 fewer overweight adolescents.

"Educating adolescents on the benefits of sleep, and informing them of sleep hygiene practices have shown to have little impact on adolescent sleep duration," said Mitchell. "One possible solution could be for high schools to delay the start to the school day. Previous research has shown that delaying the start of the school day even by 30 minutes results in a 45-minute per day increase in sleep. Since our study shows increasing sleep by an hour or more could lead to a lower BMI, delaying the start of the school day could help to reduce obesity in adolescents."

add to favorites email to friend print save as pdf

Related Stories

Walking may lessen the influence of genes on obesity by half

Mar 14, 2012

Watching too much TV can worsen your genetic tendency towards obesity, but you can cut the effect in half by walking briskly for an hour a day, researchers report at the American Heart Association's Epidemiology and Prevention/Nutrition, ...

Recommended for you

Gut bacteria promote obesity in mice

13 hours ago

A species of gut bacteria called Clostridium ramosum, coupled with a high-fat diet, may cause animals to gain weight. The work is published this week in mBio, the online open-access journal of the American Society for Microbiol ...

An apple a day could keep obesity away

22 hours ago

Scientists at Washington State University have concluded that nondigestible compounds in apples – specifically, Granny Smith apples – may help prevent disorders associated with obesity. The study, thought ...

Boosting purchasing power to lower obesity rates

Sep 25, 2014

In January, as one of the first major initiatives of the Academic Vision, the Rudd Center for Food Policy and Obesity will move to UConn from Yale University. The move will allow Rudd faculty to expand their work and build ...

Note to young men: Fat doesn't pay

Sep 23, 2014

Men who are already obese as teenagers could grow up to earn up to 18 percent less than their peers of normal weight. So says Petter Lundborg of Lund University, Paul Nystedt of Jönköping University and ...

Waistlines of US adults continue to increase

Sep 16, 2014

The prevalence of abdominal obesity and average waist circumference increased among U.S. adults from 1999 to 2012, according to a study in the September 17 issue of JAMA.

User comments