It doesn't matter whether a child is three or 13, kids who spend big chunks of time in front of their computers, televisions, tablets and cell phones are prey to a wide range of problems.

Children who spend hours in front of screens tend to be overweight and prone to diabetes and heart trouble. They get too little sleep, do more poorly in school, and are more likely to have behavior and psychological issues.

Most parents know that spending time in front of a screen is not doing their children any favors, to put it mildly. But they may not realize they can do a lot to protect their children from the negative effects of too much screen time. All they have to do is pay a little more attention.

When parents talked with their children about what they were watching and restricted the amount of content they watched, it reduced many of the negative effects of screen time.

Iowa State University researchers analyzed information about 1300 third to fifth graders who were part of an obesity prevention program. Children reported on the shows they liked to watch and games they liked to play, describing how violent they found them. Their teachers and parents or primary caregivers provided information on their sleep habits and school performance.

The researchers found that, “…[T]he effects of parental involvement on children’s media habits are neither simple nor direct… ” When parents spent more time monitoring children's total screen time, their children did better in school and showed less aggressive behavior; when parents succeeded in getting their children to sleep more, their children's body mass index (BMI) was lower.

When parents talked with their children about what they were watching and restricted the amount of content they watched, it reduced many of the negative effects of screen time.

“Pediatricians, family practitioners, nurses and other health care professionals who encourage parents to be more involved in their children's media may be much more effective at improving a wide range of healthy behaviors than they realize,” Donald Shifrin, MD, a professor in the Department of Pediatrics, at University of Washington School of Medicine, said in a viewpoint accompanying the study.

“It should not be our sad legacy to be labeled as media curmudgeons, focusing only on the drawbacks of unlimited media consumption. We can also extol the many benefits of technology…However, it would be folly to praise the promise of technology, while ignoring the peril.”

The study is published in JAMA Pediatrics.