Teletubbies: fat ad budgets and fat kids.

A FEBRUARY REPORT from the Kaiser Family Foundation noted that kids who watch a lot of TV are more likely to be fat than kids who don't. It said exposure to food commercials was the most likely explanation. That theory fit well with recent press coverage of the issue: A study released in June by the Media Research Center's Free Market Project found that news reports overwhelmingly blame food vendors' attempts to pad their bottom lines for Americans' expanding waistlines.

One problem with linking fat kids to fat ad budgets is that TV ads for food are not a new development, as those of us whose heads still ring with the slogans and jingles of the 1970s can attest. Despite their heavy exposure to the Trix rabbit, the Keebler elves, and Ronald McDonald, that generation of kids was not especially heavy. According to the U.S. Centers for Disease Control and Prevention, about 6 percent of Americans between the ages of 6 and 19 were overweight in the mid-to-late 1970s, compared to 15 percent in 2000.

If anti-fat activists are right that advertising plays an important role in rising obesity among children, perhaps it's because today's kids see more of it than their parents did. Yet Todd Zywicki, a George Mason University law professor who recently served as director of the Federal Trade Commission's Office of Policy Planning, found just the opposite: If anything, kids see fewer food ads than they did when they were thinner.

Zywicki, whose conclusions will be reported in an upcoming issue of the George Mason Law Review, notes that the frequency of food ads has not increased, while kids are spending less time watching broadcast television and more time playing video games, using computers, and watching cable TV, videotapes, and DVDs--media with fewer or no food ads. Meanwhile, the proliferation of remote controls and increased watching of programming on VCRs and DVRs have made it easier to skip commercials.

At a Cato Institute forum in June, Zywicki proposed a thought experiment to test the plausibility of the idea that advertising has a substantial impact on weight. He asked his audience to imagine a fat child who watches six hours of Nickelodeon a day. Would you expect him to get thinner if his parents switched him to six hours of commercial-free PBS programming?

Probably not. "Watching too much TV is going to make you fat," Zywicki said, since it's a sedentary activity and people tend to snack while they watch. But if advertising had the influence its critics suggest, "the PBS diet would work."

And while you're contemplating the kid on the couch, don't forget the dog in the corner. "Our dogs are getting overweight for exactly the same reasons we are," Zywicki noted. "They're eating too much and exercising too little. They're not watching too much advertising."