Parents should have a media use plan to account for the quantity, quality and location of media that their children use, experts say.

The average 8- to 10-year-old spends nearly eight hours a day with a variety of media; older children and teens spend more than 11 hours a day, according to the American Academy of Pediatrics.

Nearly all children and teens (84 percent) are online; about 75 percent of 12- to 17-year-olds have a cellphone, up from 45 percent in 2004.

The overwhelming prevalence of media in the average child's life is cause for concern, USA TODAY reported.

"We are worried that a lot of parents are clueless about their kids' media use and how to manage it appropriately," said Victor Strasburger, a professor of pediatrics at the University of New Mexico and co-author of the AAP policy statement, released at the group's national conference in Orlando, Fla.

A new, nationally-representative survey from the nonprofit advocacy group Common Sense Media shows that 72 percent of kids ages 8 and under have used a mobile device for some type of media activity such as playing games, watching videos or using apps, up from 38 percent just two years ago. Of these young children, 17 percent use a mobile device on a daily basis.

They are "spending more time with media than they are in school. They are spending more time with media than in any activity other than sleeping. You could make the argument that media have taken over the primary role of teaching kids from schools and parents in many cases," Strasburger said.

Excessive media use has been associated with obesity, lack of sleep, school problems, aggression and other behavior issues. 

The American Academy of Pediatrics recommends limiting the amount of total entertainment screen time to less than two hours a day and to discourage all screen media exposure for children under age 2.

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