BIRMINGHAM, England — Children who stay up late or get insufficient sleep are more likely to be overweight, a new study finds.

Researchers at the University of Birmingham, along with academic researchers in China, looked at data of nearly 2,800 Chinese adolescents, aged 9 to 12, exposing a link between body fat percentage and unhealthy sleeping habits.

Sleeping child
Children who stay up late or get insufficient sleep are more likely to be overweight, a new study finds.

While similar studies had been conducted in the U.S. and Europe, Chinese youth are notorious for neglecting sleep — likely the consequence of an extreme focus on academic achievement — leading the researchers to examine the effects of such differences.

Chinese children who slept longer had lower Body Mass Index (BMI) scores. In addition, there was a small increase in BMI for every hour that one delayed their nightly slumber. No matter how small the change in BMI, there was a correlation to significant changes in health outcomes, the researchers noted.

While the benefits of sleep have never been better documented, sleep duration has decreased in recent years among adolescents across regions.

Perhaps one reason for weight gain among night owls is the increased incidence of unhealthy behaviors, such as watching TV and snacking. Sleep-wake cycles may also be interrupted, the researchers speculate, leading to one further packing on the pounds.

“The prevalence of obesity in China is alarming as the country undergoes rapid economic transition, leading to changes in traditional diet, increased sedentary lifestyles, and reduced physical activity,” explains researcher Yajun Chen in a press release.

“There are complex factors contributing to childhood obesity, including biological and lifestyle factors,” he adds, “but increasing observational research reports that shorter sleep duration may be an additional risk factor associated with higher body mass index (BMI) among children.”

The study’s findings were published in the Journal of Epidemiology.

About Daniel Steingold

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