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February 09, 2010

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Child obesity: It’s the TV food ads, not the TV, study finds

Feb. 9, 2010
Courtesy UCLA
and World Science staff

To head off obes­ity in your kids, you don’t have to pro­hib­it TV, some sci­en­tists are ad­vis­ing. In­stead, they say, steer young­sters to­ward pro­gram­ming with­out junk-food com­mer­cials, such as educa­t­ional chan­nels or DVDs.

That’s be­cause a new study in­di­cates the link be­tween TV and child­hood obes­ity has more to do with the num­ber of spots push­ing junk food than with the amount of TV watch­ing it­self.

Uni­vers­ity of Cal­i­for­nia Los An­ge­les re­search­ers gath­ered da­ta from pri­ma­ry care­givers of 3,563 chil­dren, rang­ing from in­fants to 12-year-olds, in 1997. Through time-use di­aries, study re­spon­dents re­ported their chil­dren’s ac­ti­vi­ties, in­clud­ing TV view­ing, through­out a full week­day and week­end day.

Care­givers were al­so asked to re­port the for­mat—TV pro­grams, DVDs or videos—and the names of the pro­grams watched. This da­ta was used to clas­si­fy view­ing in­to ei­ther educa­t­ional or en­ter­tain­ment, and to find out wheth­er it con­tained ad­ver­tis­ing or prod­uct place­ment. A fol­low-up was con­ducted in 2002.

The anal­y­sis ac­counted for the amount of phys­i­cal ac­ti­vity and the chil­dren’s gen­der, age, eth­nicity, moth­er’s weight sta­tus, educa­t­ion and sleep time. Com­mer­cial view­ing was sig­nif­i­cantly as­so­ci­at­ed with high­er body mass in­dex, a stand­ard meas­ure of obes­ity, the study found; the ef­fect was stronger for chil­dren un­der sev­en.

The re­sults sug­gest “the as­socia­t­ion be­tween com­mer­cial tel­e­vi­sion view­ing and obes­ity does not arise solely or even pri­marily be­cause heav­i­er chil­dren pre­fer com­mer­cial tel­e­vi­sion,” said Fred­er­ick J. Zim­mer­man, chair of Health Ser­vic­es at the uni­vers­ity’s School of Pub­lic Health and the stu­dy’s lead au­thor.

Non-com­mer­cial view­ing, in­clud­ing DVDs or educa­t­ional tel­e­vi­sion, had no sig­nif­i­cant as­socia­t­ion with obes­ity, the au­thors added. The find­ings, they said, al­so sug­gest that steer­ing chil­dren away from com­mer­cial tel­e­vi­sion may be ef­fective in re­duc­ing child­hood obes­ity, giv­en that food is the most-ad­ver­tised prod­uct on chil­dren’s tel­e­vi­sion that al­most nine in 10 chil­dren start watch­ing the tube reg­u­larly be­fore age two.

By the time they’re five, chil­dren have seen an av­er­age of more than 4,000 food com­mer­cials an­nu­al­ly, the re­search­ers not­ed; and dur­ing Sat­ur­day morn­ing car­toons, chil­dren see an av­er­age of one food ad eve­ry five min­utes, mostly for junk food. “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 au­thors con­clude that the avail­abil­ity of high-qual­ity, en­joy­a­ble and educa­t­ional pro­grams for all ages on DVD should make it rel­a­tively easy for health ed­u­ca­tors and care providers to nudge chil­dren’s view­ing to­ward con­tent that’s health­ier for mind and body.

“Just as there are far bet­ter and more nu­tri­tious foods than those ad­ver­tised on tel­e­vi­sion, there are al­so far bet­ter and more in­ter­est­ing shows on tel­e­vi­sion than those sup­ported by ad­ver­tis­ing,” Zim­mer­man said. “Edu­ca­t­ional tel­e­vi­sion has come a long way since to­day’s par­ents were chil­dren, and there are now many fan­tas­tic shows on com­mer­cial-free tel­e­vi­sion and, of course, won­der­ful con­tent avail­a­ble on DVD.”

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

* * *

To ward off obesity in your kids, you don’t have to prohibit TV, some scientists are advising. Instead, they say, steer youngsters toward programming without junk-food commercials, such as educational channels or DVDs. That’s because a new study indicates the link between TV and childhood obesity has more to do with the number of commercials for junk food than with the amount of TV watching itself. University of California at Los Angeles researchers gathered data from primary caregivers of 3,563 children, ranging from infants to 12-year-olds, in 1997. Through time-use diaries, study respondents reported their children’s activities, including TV viewing, throughout a full weekday and weekend day. Caregivers were also asked to report the format—television programs, DVDs or videos—and the names of the programs watched. This data was used to classify television viewing into either educational or entertainment programming and to find out whether it contained advertising or product placement. A follow-up was conducted in 2002. The analysis accounted for the amount of physical activity and the children’s gender, age, ethnicity, mother’s weight status, education and sleep time. Commercial viewing was significantly associated with higher body mass index, a standard measure of obesity, the study found; the effect was stronger for children under seven. The results suggest “the association between commercial television viewing and obesity does not arise solely or even primarily because heavier children prefer commercial television,” said Frederick J. Zimmerman, chair of health services at the university’s School of Public Health and the study’s lead author. Non-commercial viewing, including watching DVDs or educational television programming, had no significant association with obesity, the authors added. The findings, they said, also suggest that steering children away from commercial television may be effective in reducing childhood obesity, given that food is the most-advertised product on children’s television that almost nine in 10 children start watching the tube regularly before age two. By the time they’re five, children have seen an average of more than 4,000 food commercials annually, the researchers noted; and during Saturday morning cartoons, children see an average of one food ad every five minutes, mostly for junk food. “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 authors conclude that the availability of high-quality, enjoyable and educational programs for all ages on DVD should make it relatively easy for health educators and care providers to nudge children’s viewing toward content that does not contain unhealthy messages about food and eating. “Just as there are far better and more nutritious foods than those advertised on television, there are also far better and more interesting shows on television than those supported by advertising,” Zimmerman said. “Educational television has come a long way since today’s parents were children, and there are now many fantastic shows on commercial-free television and, of course, wonderful content available on DVD.” The study is published in the American Journal of Public Health.