Washington, Feb 10 (IANS) The link between TV viewing and childhood obesity is directly related to children’s exposure to ads that publicise unhealthy foods, says a new study.
Conducted by Frederick J. Zimmerman and Janice F. Bell, of the University of California - Los Angeles (UCLA), the study is the first to break down the types of TV children watch to better determine whether different kinds of content may exert different effects on obesity.

Researchers gathered data from primary caregivers of 3,563 children, ranging from infants to 12-year-olds, in 1997.

Caregivers were also asked to report the format — TV programmes, DVDs or videos — and the names of the programmes watched.

This data was used to classify TV viewing into either educational or entertainment programming and to determine whether or not it contained advertising or product placement. A follow-up was conducted in 2002.

Among all children, commercial viewing was significantly associated with higher BMI, (body mass index) or height to weight ratio, although the effect was stronger for children younger than seven years than for those older than seven, the study found.

“The persistence of these results, even when the child’s baseline weight status was controlled, suggests that the association between commercial television viewing and obesity does not arise solely or even primarily because heavier children prefer commercial television,” said Zimmerman, professor and chair of health services at the School of Public Health, who led the study.

Non-commercial viewing, including watching DVDs or educational television programming, had no significant association with obesity.

By the time they are 5 years old, children have seen an average of more than 4,000 TV commercials for food annually, said an UCLA release.

“Commercial television pushes children to eat a large quantity of those foods they should consume least: sugary cereals, snacks, fast food and soda pop,” Zimmerman said.

The study was published in the American Journal of Public Health.