Increased sleep could reduce rate of adolescent obesity

April 8, 2013

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."

Explore further: Lack of sleep leads to insulin resistance in teens

Related Stories

Lack of sleep leads to insulin resistance in teens

September 29, 2012
A new study suggests that increasing the amount of sleep that teenagers get could improve their insulin resistance and prevent the future onset of diabetes.

Walking may lessen the influence of genes on obesity by half

March 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, ...

Longer sleep times may counteract genetic factors related to weight gain

May 1, 2012
Toss out another old wives' tale: Sleeping too much does not make you fat. Quite the opposite, according to a new study examining sleep and body mass index (BMI) in twins, which found that sleeping more than nine hours a ...

Recommended for you

Kids with weight issues at high risk of emotional and behavioural problems

August 10, 2017
A new, in-depth study of New Zealand children and teenagers seeking help with weight issues has found their emotional health and wellbeing is, on average, markedly worse than that of children without weight issues.

Study finds 90 percent of American men overfat

July 24, 2017
Does your waist measure more than half your height?

Are sugary drink interventions changing people's behaviour?

July 19, 2017
An evaluation of efforts designed to reduce how many sugary drinks we consume shows some success in changing younger people's habits but warns they cannot be the only way to cut consumption.

Young adult obesity: A neglected, yet essential focus to reverse the obesity epidemic

July 18, 2017
The overall burden of the U.S. obesity epidemic continues to require new thinking. Prevention of obesity in young adults, while largely ignored as a target for prevention and study, will be critical to reversing the epidemic, ...

Weight gain from early to middle adulthood may increase risk of major chronic diseases

July 18, 2017
Cumulative weight gain over the course of early and middle adulthood may increase health risks later in life, according to a new study led by researchers from Harvard T.H. Chan School of Public Health. They found that, compared ...

Study finds children carry implicit bias towards peers who are overweight

June 23, 2017
Even children as young as 9 years old can carry a prejudice against their peers who are overweight, according to a new study led by Duke Health researchers. They might not even realize they feel this way.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.