Commercials Are the Culprit in TV-Obesity Link

By TARA PARKER-POPE

Too much time in front of the television has long been linked to childhood obesity. Now, new research suggests it’s not the TV but the commercials that are making kids fat.

In a study of more than 2,000 children, researchers from the University of California, Los Angeles, compared the time the kids spent viewing television and video. They asked caregivers to track children’s media use during one weekday and one weekend day during 1997, then again in 2002.

The findings showed that the amount of television a child watched wasn’t a predictor of obesity risk. Instead, risk for being overweight increased the more television commercials a child was exposed to. There was no association with television viewing and obesity for those who watched videos or commercial-free programming.

Although the effect was seen among all children studied, it was strongest for children younger than 7, according to the report in The American Journal of Public Health.

Because people with more education and better eating habits might also insist their children watch videos or PBS rather than commercial television, the study authors controlled for a number of other factors that might influence the findings. They looked at such variables as the mother’s weight and education level, the child’s starting weight and overall physical activity, time spent eating in front of the television and even the amount of sleep children were getting. Even after controlling for these factors, the link between commercials and weight gain remained.

Fred Zimmerman, the study’s lead author and chairman of U.C.L.A.’s Department of Health Services, said television commercials for sweetened cereals, junk food and fast food chains probably had an insidious influence over a child’s food preferences. The more television commercials a child is exposed to, the more likely he or she will be to try those foods and want to continue eating them, which then increases risk for weight gain.

Although it’s long been speculated that television viewing is associated with a lack of physical activity, that’s often not the case. Young children often stand, jump and wiggle while watching television, and children who play sports also may be watching more sports programming.

“There’s been a fair amount of work showing TV viewing is associated with obesity,’’ Dr. Zimmerman said. “What’s new about this research is that it suggests there’s no evidence of a couch potato effect. It’s highly suggestive that it’s the effect of watching TV commercials.’’

The study wasn’t able to document how much food advertising children were exposed to. But research shows that young children are exposed to about 30 hours of food-related advertising annually. During Saturday cartoons, children see an average of one food ad every five minutes, most of which are for junk food, the researchers noted.

“Advertisers have been clever about building brand loyalty, making these foods seem attractive,’’ Dr. Zimmerman said. “I was talking with one of my graduate students who was saying, ‘When I was a kid, it was just a dorky rabbit talking about Trix.’ Now it’s about being cool, and what’s fun and exciting. It really grabs your emotions much more powerfully than it used to.’’

For more information on obesity, see the Times Topics Obesity Page.