TV-watching in kids and teens has already been linked with higher risk for overweight, sleep problems and a taste for junk food. Now, a new University of Pennsylvania study says that leaving the TV on in the background could lead to learning and reading problems in kids ages eight months to eight years old.

Matthew Lapierre, a doctoral candidate at the University of Pennsylvania's Annenberg School for Communication, surveyed the parents of 1,450 kids. He found that the kids spent an average of 4 hours a day with the TV on in the background. That's in addition to the 80 minutes of programs they actually watched daily. This study didn't measure kids' reading or learning abilities, but cites other research that has. In one, kids from heavy-TV homes read less and were less likely to be early readers.

Two out of three little kids, ages zero to six, live in a household where the TV's on at least half the time – and in many, it's left on most of the time according to a Kaiser Family Foundation survey of 1,000 families.  One in four kids under two have a TV in their bedroom, too. So what's wrong with TV as sonic wallpaper? Three things, Lapierre says:

  • More TV = less time with books.  Kids in "heavy TV" households are less likely to read everyday and when they do its for a shorter time than kids in households that watch less TV, another survey says.

  • More TV = less interaction with you.  When kids and their care-givers play without the TV on, they tend to play together longer and to be more involved in what they're doing than when the TV's blaring in the background. Nobody stops to check what's happening on the screen.

  • More TV = less attention to everything else around them. Little kids aren't multi-taskers. If the TV's on they have a hard time focusing on anything else, including playing with toys, say University of Massachusetts researchers.

TV's not all bad, of course. Keep the good (like educational shows, fun movie nights with the family, a couple of favorite shows) and get rid of the excess with these smart steps recommended by the Nemours Foundation:

  • Stock the TV room with 'distractions' – kids' books, magazines, puzzles, games, toys – so they have an alternative.

  • Turn TV off during homework and meal times.

  • Set a daily limit (many experts recommend 2 hours of screen time a day).

  • Grab the TV schedule and plan TV-watching as a family.

  • Then watch together, so you can talk together about what you're seeing and change the channel if something inappropriate pops up.

  • Set a good example. Limit your own TV time and be available to do other fun stuff with your kids, like playing board games, swinging on the swings, reading together.

For more information on selecting family-friendly TV shows and the effects of TV and other media on kids and teens, check the Web site of the watchdog group the Parents Television Council.

What do you think? Is it difficult turning off the TV because you're busy or your kids want to watch more? If you're setting TV limits, what family activities are happening at your house when the TV's off?