Not all screens are equal when it comes to obesity risk: TV may have greatest effect
April 10, 2013
By Bonnie Rochman
Sitting in front of a screen can increase the risk of obesity, but TV seems to have a larger effect on weight than computers or video games.
Computers, televisions, smartphones, and tablets are all responsible for keeping more kids more sedentary and mesmerized by a screen, but a new study in Pediatrics found some surprising differences among these devices and their relationship to childhood obesity. It turns out that only television — in particular, paying close attention to what’s on the tube — is associated with heavier kids. In a study of young teens, 14-year-old boys who reported paying the most attention to what was playing on television weighed 14.2 pounds more than boys who reported paying the least attention. For girls, the difference was 13.5 pounds.
The study, conducted by researchers at Boston Children’s Hospital, took an intensive look at what media 91 teens between the ages of 13 and 15 use most and how they used these devices. The scientists signaled the kids at random times during the study via smartphone to report their activities — were they playing sports, or doing homework, or surfing the web? If they were doing multiple activities at once — texting and watching television, for example — which activity were they focused on?
Researchers also recorded height and weight measurements of the participants and calculated the kids’ BMI, or body mass index. They found that teens spent more than three hours a day watching television — more time than they spent with any other sort of screen — and that those teens who paid the most attention to the shows they were watching had the highest BMI. Meanwhile, paying close attention to video games or computers was not linked with weighing more.
Why? While watching television, says Michael Rich, director of the Center on Media and Child Health at Boston Children’s Hospital and the study’s senior author, kids are bombarded with advertising for high-calorie snack foods, and at the same time, their hands are free to allow them to munch at will as opposed to when they are playing video games or using the computer or texting, which occupies their fingers more.
“If you’re paying attention to TV, you’re not paying attention to hunger cues,” says Rich, who is also an associate professor of pediatrics at Harvard Medical School. “Big picture, it’s not how much time any screen is on. It’s what screen is on, what content is on that screen, and what else is my child doing while absorbing that content.”
With so much screen-based media now available to children, Rich believes it doesn’t make sense to shun screen time completely. In fact, he says that guidelines that tell parents to clamp down on their kids’ screen time are likely to be futile. “That advice has gotten virtually zero traction,” he says. “Kids’ screen time just keeps going up and up and up.”
Instead, a more practical approach for pediatricians might be to fine-tune their advice, helping parents shape their children’s media use rather than cut it back. His suggestion: Be mindful of the content that kids are watching. Be aware that kids’ risk of being overweight is increased by watching lots of television.
Does that mean pushing kids toward the iPad rather than the boob tube? Rich wouldn’t exactly endorse that approach. But it’s more likely that teens will respond positively to being weaned off the television if a different screen is offered in its place.
“Screens are now part of the environment that these kids are living in,” says Rich. “It’s like the air they breathe and the water they drink.” It’s just a matter of being aware of what’s on those screens that are keeping children so absorbed.