If you're a parent who polices how much time your children spend watching TV, playing video games or on the computer, they may be benefiting more than you know.  A new study finds parents who monitor their child's screen time have kids who get more sleep, do better at  school and behave less aggressively.

"So, we recommend that children spend a total of two hours a day, or less, on all of their screen time. That includes cell phones, computers, video games, tablets, and that can be a big challenge for kids and their families, but it's really important," said Cleveland Clinic Pediatrician Dr. Kim Giuliano, who did not take part in the study.

Iowa State University researchers looked at self-reported screen time data on nearly 15-hundred school children. All of the kids were in the 3rd through the 5th grade. They found increased monitoring by parents reduced a child's total screen time and led to the child getting more sleep, doing better in school, and behaving less aggressively. It also resulted in less exposure to violent television programs and video games.

Researchers say parents who are involved in their child's media may also be more effective at encouraging a variety of healthy behaviors in their children. Giuliano says if you have questions about ways to reduce your child's screen time talk to your pediatrician.

"We address it in almost every well-child care visit. The quantity and the quality of the electronic time that kids are playing is really, really important to help keep kids physically active, safe, and to help their developing brains," said Giuliano.

Complete findings for this study are in the journal JAMA Pediatrics.