MONDAY, May 7, 2012 (HealthDay News) -- Kids who spend lots of time in front of the TV have poorer diets overall, a new study of U.S. middle school students finds.
The research doesn't prove that TV watching has anything to do with what kids eat, and other factors -- such as parenting style -- could be more important than time spent with "American Idol" or "SpongeBob SquarePants."
Still, "the more TV you watch, the less likely you were to eat fruits and vegetables every day, and the more likely you were to eat things like candy and soda, eat at a fast food restaurant and even skip breakfast," said study author Leah Lipsky, a staff scientist with the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Previous research has linked more TV watching to obesity in kids, she said, perhaps because the children are less active and snack more.
But study co-author Ronald Iannotti, also a staff scientist at the institute, said the issue is complicated. In some cases, for example, boys who are more active tend to watch more TV.
"There's some evidence that TV may be its [own] unique risk factor. It could be because your metabolic rate is so low that it's just worse than doing anything else," Iannotti said.
Seeking to better understand how TV watching affects diet, the researchers examined data from a 2009-2010 survey of more than 12,600 U.S. youngsters in grades 5-10, average age 13. The findings appear in the May issue of the Archives of Pediatrics & Adolescent Medicine.
The study found that those who watched the most TV were slightly more likely to eat candy and fast food and skip breakfast, even when researchers adjusted their statistics so they wouldn't be thrown off by factors such as computer use and physical activity.
Also, eating habits appeared to deteriorate according to age, gender and race. Unhealthy eating habits were more common among older students than younger ones and more prevalent among boys and black or Hispanic students compared to girls and white students.
"In some cases, the effect is very small. On the other hand, these effects can be huge when you think of even a slight increase in food intake affecting 200,000 sixth graders," Iannotti said.
A positive note was that those who snacked the most while watching TV also ate more fruit (in addition to more candy, soda and fast food).
So, is TV at fault? The researchers acknowledged that other factors could play a role, such as parents who allow both TV watching and poor diets. The study authors didn't take household rules into account.
The authors said that future research should try to tease out the independent contributions of food advertising, TV time and TV snacking to food consumption among children. If it turns out that a cause-and-effect relationship does exist, attempts should be made to limit viewing or improve the nutritional content of foods advertised on TV, they said.
Frederick Zimmerman, chair of the health services department at the Fielding School of Public Health at the University of California, Los Angeles, said the study is well-conducted, but "a little behind the current research curve" with regard to food advertising's effects on health and eating behavior.
"Other research has shown that physical activity tends to make us crave those inputs that are healthiest for us, whether in the realm of food or entertainment," Zimmerman said. "Regular daily physical activity -- especially outdoors -- is what we're designed for and the natural and enjoyable state of human beings. If we can enjoy regular physical activity, we can let go of some of the anxiety on TV and diet, because we'll naturally want what's healthy for us."
For more on obesity in children, visit the U.S. National Library of Medicine.