Children and teenagers who spend a lot of time in front of a television screen are more likely to gain extra weight as they age, according to a study Reuters reported.
In the study, researchers found increases in total screen time were linked with similar changes in the body mass index (BMI).
"The weight of the evidence is pretty strong that television viewing is related to unhealthy changes in weight among youth," Jennifer Falbe, lead researcher at the Harvard School of Public Health in Boston, told Reuters. "It's important for parents to be aware of all the potentially obesogenic screens that they should really be limiting in their children's lives."
Researchers used data from a long-term study of 7,800 kids who took surveys every other year. They asked participants questions about their height and weight, as well as, how much time they spent watching TV, DVDS and playing computer and video games, Reuters reported. The kids involved in the study were between ages nine and 16 when the study started
Researchers observed that 20 percent of the children they observed carried extra weight. Seventeen percent of the 4,300 girls in the study were overweight or obese, while 24 percent of the 3,500 involved in the study were above a healthy weight.
Based on the study, each one-hour increase in children's daily TV watching was tied to an increase of about 0.1 points on a BMI scale, which measures weight in relation to height. That's a difference of approximately half a pound per extra hour of TV.
Increases in DVD and video watching were tied to weight gain among girls, in particular.
Mark Tremblay, who was not involved with the study, told Reuters most U.S. and Canadian children exceed the recommended two-hour maximum of recreational screen time.
"We don't pay attention to the fact that it's half an hour here, half an hour there, an hour here, an hour there," Tremblay, director of Healthy Active Living and Obesity Research at the Children's Hospital of Eastern Ontario Research Institute in Ottawa, Canada,told Reuters Health.
Tremblay added children are most likely to gain weight watching TV because their "hands are free when ... watching TV, so should that temptations capture [them], [they're] able to sit there and munch on [something] whether it's a healthy or an unhealthy snack."
He noted kids sitting down playing a computer game might be more active, because sitting on the couch while watching television allows children and teens to enter a hibernative state.
The research's findings are consistent with previous studies that have concluded idle sitting and exposure to advertisements fuel poor eating habits.
