As most parents know by now, the experts say we should limit our kids' screen time or risk raising socially stunted couch potatoes.
Last fall, the American Academy of Pediatrics released updated guidelines for children and adolescents using media, recommending no more than two hours per day of any type of entertainment screen time for kids ages 3 to 18 and none for children 2 or younger. The guidelines cover media such as Internet and texting as well as TV, movies and video games.
As a science writer, I wondered how the AAP decided on that limit, which seems arbitrary and simplistic. As a mother raising a 3-year-old and a 6-year-old in a house full of glowing screens, I wondered, how would I ever enforce it?
Victor Strasburger, a professor of pediatrics at the University of New Mexico in Albuquerque and an AAP spokesman, explained that the two-hour cutoff comes from several large studies that have followed the television-watching habits and health of children over decades.
"Over two hours per day, and the more time spent in front of a screen, the higher the risk of obesity," he said.
With more than two hours of screen time per day, kids are also more likely to experience a drop in school performance and increased aggression, Strasburger said. "There is a displacement effect. If you are spending seven hours with media, those are hours you are not walking the dog, playing on the soccer team or hanging out with friends."
Recent studies followed thousands of European preschool and school-age kids and linked upward-creeping screen time to emotional and family problems and to a lack of sleep.
There is not much research yet to determine if different types of screens are worse for kids' development than others, but a large recent study highlights differences between TV-watching and game-playing: more than three hours per day of television was linked to worse conduct, but the same stretch of video gaming was not.
AAP spokeswoman Marjorie Hogan advises families to cultivate a "healthy media diet" with all things in moderation.
"It starts when kids are very, very small," she says. Families should determine which media they will use, and things like whether the TV should be turned off when not in use and always during meals, Hogan said. "Remember, diet is not only the choices you make, but also the amount of programming."
When it comes to teens, the challenge may be greater: Seventy-seven percent of 12- to 17-year-olds own cellphones, and the average teenager sends more than 3,300 text messages a month, according to a 2011 study.
"The multi-tasking aspect for teens is huge," says Megan Moreno, director of the Social Media and Adolescent Health Research Team at Seattle Children's Research Institute.
Her group found that older teens spend more than half their time online multi-tasking, with typically four applications open simultaneously. That may not sound like a lot, but it is to an adolescent's brain that is still developing cognitive and social skills.
The newness of new media means not much is known yet about its health impact on teens, Moreno says. Kids aren't complaining about Facebook-induced headaches, she says, but in surveys college students have noted weight loss or gain, lost sleep and vision problems because of Internet use.
How well do the AAP guidelines translate for new media? "We don't have that answer yet," Moreno said, adding that it may be more appropriate to increase screen time to up to four hours per day for older teenagers.
Worries that children and teens will encounter horrifically explicit content on the Web or strike up relationships with strangers are largely misplaced, according to Moreno and Michele Ybarra, research director at the Center for Innovative Public Health Research in San Clemente, Calif.
Most kids use the Internet to "extend their face-to-face relationships," says Ybarra. When surveyed, only 3 to 6 percent of 10- to 15-year-olds had knowledge of violent and sexually explicit sites.
To ensure a healthy media diet, experts suggest developing a family media plan:
• Enforce consistent rules about screen time from the start.
• Keep all screens and Internet out of the bedroom.
• Impose mealtime restrictions and bedtime curfews for everyone's devices.
• Watch or explore media content with children.
Ultimately, media are not inherently good or bad, but simply another facet of family life. Parents should sit, view and discuss content with children, especially if media messages conflict with family beliefs or house rules, experts say.
"There's no longer any need for the Big Talk," Strasburger said. "You should have had 75 small talks while watching 'The Following' or 'Bones.'"
For many parents who didn't have email until college, the Internet is a resource along the lines of a phone book or an encyclopedia. "But for young people," Ybarra said, "it's a place or a space," for social interaction, and parents "need to begin to see it that way, too."
I'm slowly coming around to the idea that I'll be meeting up with my kids in front of or through their small screens for years to come. I just hope they'll always enjoy a balanced blend of scooters and screens, desserts and vegetables, alike.