Of all the many reasons cited to reduce kids’ time on screen, the link between screens and obesity gets trotted out pretty often. The thinking is that children who spend a lot of time sitting, either watching television or playing video games, are not running around and so are getting fatter. The connection between screens and obesity has come to seem logical.

Now a study from University of Michigan suggests that it’s not the screens and the sitting but the eating-while-sitting that makes the difference. Kids who watch television eat more while they sit than do kids who play video games. TV and snacking go hand-in-hand. For video gamers, snacking is a separate, not a simultaneous, activity.

In the study, over 1000 sixth-graders from 24 Michigan middle schools filled out a questionnaire that asked about the type and frequency of their screen usage, their snacking habits and what they ate and drank in the previous day. The students were divided into three groups: low screen time (less than 30 minutes per day), high TV time (2 to 6 hours of television daily), and high computer/video time (2 to 6 hours of video games daily).

The outcome was that kids who spent more time in front of any screen – television or video games – snack more than low-screen kids and choose less healthy snacks. They report eating one additional snack each day over the number reported by low-screen kids. But kids who watch television 2 to 6 hours a day were more likely to eat high-fat foods like chips and French fries than did the kids who play video games for 2 to 6 hours each day. Video gamers snacked but snacked on more healthy foods than television watchers.

The researchers suggest that television supports snacking because of food-focused commercials. Certainly advertisements for fast food, snack foods, and even for cooking shows dominate much of the commercial time on programs aimed at children and families. The programs themselves, including commercial-free movies for children, often include eating and snacking sequences, sometimes with specific products prominently “placed.” Video games have far less food-related content.

Video-gamers suggest that the vulnerability of the video equipment to crumbs and liquids inclines kids to keep food away from their computer screens. Parents are more likely to enforce a no-food rule at the computer or tablet than they are in front of the TV. In addition, video game play keeps hands busy. There are neither time nor fingers available to snacking.

The American Academy of Pediatrics estimates that, on average, children spend 7 hours a day on screen-based entertainment, of which 4 ½ hours are television. This is in addition to the 6 hours kids spend at school on a weekday. Obviously very little time is left over for active play. Whatever calories are consumed while sitting add up instead of being burned off.

There are many reasons to get kids up off the couch and out to play. The hazards of a sedentary lifestyle are important. It may be that not only the time devoted to screens matters but also which sort of screen. At the same time, keep these ideas in mind, no matter what screen your child is glued to:

1. Limit snacking and especially restrict snacking to “good” foods. A peanut butter sandwich and a glass of milk are better than chips and soda any day. Don’t keep foods in the house that are not good for your child to eat.
2. Encourage your child to fast-forward past commercials when watching a recorded program and to mute the sound of commercials during live programs. There’s no need for your children to be a captive audience for marketers of products that are bad for them.
3. As always, limit screen time. Notice that in the University of Michigan study there actually were sixth-graders who had less than a half hour of screen time each day and these kids were the healthiest. Start now to cut back. Replace screens with reading, outdoor play, Legos, arts and crafts, and board games.
4. Set a good example. Limit your own screen time and your own snacking. What’s good for your kids is good for everyone in the family.

The more we keep kids active, mentally and physically, the healthier they will be.

© 2014, Patricia Nan Anderson. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed. Ask for Dr. Anderson’s new book, Parenting: A Field Guide, at your favorite bookstore.