Very few of America’s teenagers are meeting national recommendations for sleep, exercise and screen time, according to a study published this week in JAMA Pediatrics.

The study found that only 5 percent of U.S. high school students are achieving all three of those important health-related goals.

The findings were particularly dismal for girls: Just 3 percent of teenage girls are meeting the three health targets, compared to 7 percent of boys.

The researchers describe the findings as “startling.”

“I expected the percentage of adolescents meeting all three requirements concurrently to be low, but not this low,” said Gregory Knell, the study’s lead author and a postdoctoral researcher at the University of Texas, in a released statement.

“The results are a wake-up call for everyone who wants to make sure our children have a healthy future,” he added.

Not isolated factors

Most health guidelines recommend eight to 10 hours of sleep each night for adolescents aged 14 to 18. Health officials also recommend at least an hour of moderate or vigorous physical activity daily for teens. And they say non-educational screen time for teens should be limited to two hours daily.

Plenty of other studies have shown that large proportions of America’s teenagers are not meeting these goals. But the current study is the first time, apparently, that researchers have looked at these factors together.

That’s important because, as the researchers explain in their paper, “meeting recommendations for all 3 behaviors may have a greater association with health outcomes than meeting any 1 recommendation in isolation.”

Many disparities

For the study, the researchers analyzed data collected from almost 60,000 American high school students who participated between 2011 and 2017 in the Youth Risk Behavior Surveillance Survey, which is conducted by the Centers for Disease Control and Prevention.

In addition to the study’s overall finding — that 1 in 20 U.S. high school students did not meet all three health goals — the study also looked at the data by age, race or ethnicity, weight and mental health. They found some important disparities, particularly among vulnerable subgroups.

For example, black and Asian-American children, and those with obesity or depression were the least likely to meet all three behavioral recommendations.

Here are some of the specifics from those subgroup findings:

• Compared to children aged 14 or younger, 16-year-olds were 23 percent less likely to be meeting all three recommendations, and 17-year-olds were 46 percent less likely.
• Compared to white teens, black teens were 69 percent less likely to be meeting all three recommendations, and Asian-American teens were 63 percent less likely.
• Compared to teenagers who were not overweight, those who were overweight were 20 percent less likely, and those who were obese were 43 percent less likely, to be meeting all three recommendations.
• Compared to teenagers who were not reporting symptoms of depression on the survey, those who were reporting such symptoms were 56 percent less likely to be meeting all three recommendations.

A need to reverse the trend

The study comes with several limitations, particularly the fact that the data is based on the teenagers’ self-reports of their health-related behaviors. The information provided by such self-reports — from people of any age — can be unreliable.

Still, the findings are robust enough to be troubling. The researchers say further studies are needed to determine the effect that these three behaviors have on each other, as well as their effect on the children’s long-term health.

They also urge doctors to ask their teenage patients about these behaviors “at every patient encounter” and to advise them — and their parents — on how to modify the behaviors to create a healthier lifestyle.

“These findings are only scratching the surface and demonstrate a need to learn more about the role parenting style and home environment may play in increasing or curtailing these behaviors,” said Knell. “Although the study confirms and further reveals how few children are leading optimal lifestyle, it also raises many questions about what can be done to reverse that trend and improve their health.”

FMI: You’ll find the study, which was published as a Research Letter, on JAMA Pediatrics’ website, but it is, unfortunately, behind a paywall. For tips on how to limit your family’s screen — and sedentary — time, go to the American Heart Association’s website.