Updated on: Thursday, April 11, 2013
US researchers measured height, weight and body mass index (BMI) of the teens aged between 13 and 15 and then tracked their use of television, computers, video games and mobile screens for two weeks.
"It may seem obvious that if you're sitting at home, watching a lot of TV, you're not getting a lot of exercise, but it's much more complicated than that," said Boston Children's Hospital scientists David Bickham.
Researchers found the more and more intently children watched TV, the higher BMI they were likely to have, the 'Boston Herald' eported.
However, there was no link between video game and computer use and higher BMI levels, researchers said.
"All screen time is not the same," said Dr Michael Rich of Children's Hospital's Center for Media and Child Health.
"With video games an d the computer, your hands are busy, there's less advertising ... TV sets up an environment where food consumption is easy, Rich said. Researchers hope parents can use this data to help kids.
"If you're engaged with the TV, you're not paying attention to the food you're eating, or the cues that your body is giving." Bickham added.