It's not clear, researchers say, whether television, per se, is the culprit, but it is possible that things like snacking in front of the TV or seeing ads for junk food influence young people's diets.
The study, which included nearly 1,400 high school students, found that those who watched TV for five hours or more per day had less-healthy diets than their peers five years later.
As a group, they ate fewer fruits and vegetables, whole grains and calcium-rich foods, but downed more fast food, sugary drinks, snack products and fried foods.
"We're not able to tell why," lead researcher Dr. Daheia J. Barr-Anderson, of the University of Minnesota in Minneapolis, told Reuters Health. "But we do have some speculations."
For one, she said, people who spend a lot of time in front of the TV, especially teenagers, may snack more, and that may affect their long-term diet quality.
It's also possible that TV ads for fast food, sweets and snacks tempt teenagers to eat more of those foods, according to Barr-Anderson. TV time might also replace exercise time for some kids; however, Barr-Anderson noted, many teens who exercise also watch a lot of television.
The study was published online in the International Journal of Behavioral Nutrition and Physical Activity.
Source: Vancouver Sun / Reuters Health