WEDNESDAY, Dec. 10, 2008 (HealthDay News) -- Although genetics likely play a role in whether or not someone becomes overweight or obese, a family's lifestyle also has a major impact on the chances of a teenager winding up overweight, a new study shows.
Adolescents tended to be heavier in families that frequently missed meals or spent several hours a day in front of the TV or video games, researchers report in a special issue of the American Journal of Sociology.
"My study finds that weight runs in families, but it's not just because of genetics. What we do together, how we spend our time together, what we eat and how we organize ourselves as family matters," said study author Molly Martin, an assistant professor of sociology and demography at Pennsylvania State University in University Park.
Currently, about 17 percent of American children and teens are overweight, according to the U.S. Centers for Disease Control and Prevention.
For the new study, Martin included data from more than 2,500 pairs of twins, siblings or half-siblings. She examined numerous factors that could contribute to a teen's weight status, such as parental obesity, socioeconomic status, parental education levels, birth weight, activity levels and more.
Two factors that emerged as separate from a family's genetic influence were whether or not families missed meals, and the amount of time they spent watching TV or playing video games.
"Not skipping meals seems to be the biggest factor that can help with regard to the weight of kids," said Martin.
She said there are multiple reasons that children miss or skip meals. One is that the family may simply not have the resources to have three square meals a day, she said. Another is hectic family lifestyle, where the family could be missing a meal because they just don't have the time. Or, for some teens, they may be deliberately skipping meals in a misguided attempt to lose weight.
Whatever the reason, Martin said that when you miss a meal, you'll likely end up hungrier later and may overeat then.
"I think the importance of family meals is something that should be underscored," added Andrea Vazzana, clinical coordinator of the pediatric weight management program at the New York University Child Study Center in New York City.
"Kids that sit down with their family tend to have a more normal weight. Parents can provide structure for the meal, and the meal tends to be more well-balanced. Parents can also set limits around food," explained Vazzana, who added that when parents eat with their kids they can let them know that it's not a good idea to have two helpings of dessert first and then forgo the vegetables.
The second factor that Martin found to be a predictor of excess teen weight was how much time the family spent in front of the TV or playing video games. Those who spent a few hours daily on these activities tended to be heavier.
"Families develop patterns together," said Martin, but those patterns don't have to be bad ones. "Try to be active together. Go for a walk after dinner, play with the dog, play Frisbee. Spend quality time together that's also active time."
Vazzana said it's not just the displacement of activity that contributes to overweight, it's also that people tend to eat while they're watching TV, and they see food ads or shows that may focus on food.
"Sometimes it's really difficult to be healthy, and we may start adopting behaviors that really don't work well. But there are some things we can do consciously and even small changes can make a long-term difference in weight," said Martin.
Learn more about the causes of childhood obesity from the U.S. Centers for Disease Control and Prevention.