Limiting screen time improves sleep, academics, behavior, study finds

Douglas Gentile, lead author and an associate professor of psychology at Iowa State, says the effect is not immediate and that makes it difficult for parents to recognize. As a result, parents may think it is not worth the effort to monitor and limit their children's media use. But Gentile says they have more power than they realize.

"When parents are involved it has a powerful protective effect across a wide range of different areas that they probably never would have expected to see," Gentile said. "However, parents aren't likely to notice that putting limits on the children's media is having these effects seven months later."

Considering that children average more than 40 hours of screen time a week, not counting time spent on a computer at school, even small changes can make a difference, researchers said. They are not suggesting parents completely eliminate screen time, but find a healthy balance.

The study found there is a ripple effect associated with the benefits of limiting both screen time and media content. Gentile is not surprised to see a direct impact on sleep, academics and behavior. However, limited screen time also indirectly affects body mass index. The study found that children got more sleep if parents limited screen time, which also resulted in lower risk of obesity. Parents limiting exposure to violent media resulted in increased prosocial behavior and lowered aggressive behavior seven months later.

Researchers analyzed the media habits of more than 1,300 school children who were recruited to participate in an obesity prevention program. Students and parents were surveyed about everything from screen time limits, to violent media exposure, to bedtimes and behavior. Teachers reported grades and commented on student behavior and school nurses measured each student's height and weight.

Data were collected at the start of the program and seven months later at the end of the program. By looking at these factors collectively with a group of children over a school year, it was easier for researchers to identify patterns that are hard to recognize in individual children.

"As parents, we don't even see our children get taller and that's a really noticeable effect. With media, what we're often looking for is the absence of a problem, such as a child not gaining weight, making it even more difficult to notice," Gentile said.

"Even with changes that we do notice, we really don't recognize in the moment how all these things are related to each other across time," he added. "Yes, as screen time goes up, school performance goes down, but that doesn't happen overnight. If I watch a lot of TV today, I don't get an F in my class tomorrow."

Doctors can make a difference, too

The American Association of Pediatrics recommends no more than one to two hours of screen time a day for children two years and older. Reality far exceeds those recommendations, which might explain why doctors feel it is futile to talk with parents about guidelines for media use, Gentile said. The study provides further evidence of why pediatricians need to have that conversation.

"Hopefully, this study will give pediatricians a better sense of efficacy that it's worth taking the time to talk to parents," Gentile said. "Even if doctors only influence 10 percent of the parents, that's still millions of children having much better health outcomes as a result."

Researchers recommend doctors talk with parents about setting limits and actively monitoring media use. This can include talking with children about media content, explaining the purpose of various media and providing overall guidance.