Doctors say children shouldn't log more than two hours a day of screen time, though what with phones, computers and TV most children put in much more.
But it may be that not all screens are equally evil.
Researchers from the University of Michigan found that sixth-graders who watched a lot of TV were more likely to eat junk food and drink soda than their peers who spent the same amount of time on the computer or playing video games, researchers from the University of Michigan say.
Of course, running around outside is still much better for children's health than playing Temple Run on an iPhone. Kids who watched two to six hours a day of TV and those who played video games or used a computer for the same amount of time were heavier and had higher blood pressure than those who put in less than an hour a day of screen time, the researchers found.
Excess weight and higher blood pressure in childhood are considered risk factors for heart disease later in life.
"Our hypothesis is that when kids are watching TV, they're going to be accessing commercials that are more likely to be food related," says Dr. Elizabeth Jackson, an associate professor of medicine at the University of Michigan Health System, who led the study.
Jackson and her colleagues checked the health of 1,003 middle-schoolers and asked them about their snacking habits. The research was presented at the American College of Cardiology's Scientific Session in Washington, D.C.
Though the big consumers of TV, computer time and games all said they ate more junk food than the low-screen-time kids, the TV-watchers were most adept at eating chips and french fries.
Perhaps that because it's hard to snack on chips while your hands are busy tapping away on a keyboard or a game controller, Jackson tells Shots.
While doctors have known for a while that increasing screen time and media use also increases kids' chances of being obese, they don't usually differentiate between various types of media. Jackson says that this research was a first step in trying to tease out the differences.
But even if some types of media use are better than others, Jackson says that her research and other studies show spending less time sitting in front of any sort of screen is good for youngsters.
"As a mom and a doctor I would say it's important to limit the screen time for kids," she says. Thus teachers, parents and communities need to make sure kids spend at least a little bit of time running around and entertaining themselves the old-fashioned way.