Attention to TV is key link between screen media use and obesity

Using a new research method that tracks moment-by-moment use of electronic media by young people, researchers at Boston Children's Hospital have shown that paying attention to TV is strongly associated with higher Body Mass Index (BMI). The study, published in the May 2013 issue of Pediatrics (available online April 8), found no association between BMI and attention to video games or computers, despite the duration of use.

"These findings are based on real-time data on how kids are using media in today's complex, multitasking environment," says senior author Michael Rich, MD, MPH and Director of the Center on Media and Child Health at Boston Children's Hospital. "They indicate that it is not just how much time we use screen media, but the content to which we pay attention and what we do while watching that increases risk of obesity."

The researchers looked at 91 teens aged 13 to 15, measuring their height and weight to calculate their BMI. The teens recorded their weekday and Saturday media use, including television, computers and video games on fixed as well as mobile screens. The youth used a handheld computer to report what they were doing at random times over a week. When the computer prompted them, teens noted what they were doing and which activity they were paying the most attention to—for example, sports/activities, homework, other people, or media. Participants reported watching TV more than using any other screen media, with an average of more than 3 hours per day.

"The association between TV and increased BMI may be explained by exposure to TV ads for high calorie, nutritionally questionable foods, and eating while watching TV, which distracts from natural signals the body gives for when it is hungry or satisfied," says lead author David Bickham, PhD.

This study is based on the first findings from Measuring Youth Media Exposure, a new research method that takes an intensive, moment-by-moment look at how young people use electronic media in their daily lives, which has been developed to investigate links between media exposure and physical, mental, and social health issues among children and adolescents.