Public health researchers correlated the weight, physical activity and TV viewing habits of more than 15,000 high school students. They found that those who watched more TV were more likely to be overweight. Further, they were likely to be more overweight than those who watched less.

Overall, 45 percent reported that they participated in moderate physical activity three or more days/week, while 65 percent said they engaged in vigorous physical activity three or more days/week. About one in four reported watching TV for four or more hours a day on school days.

Boys who engaged in less moderate or vigorous physical activity were more likely to be overweight than those who got more exercise. Being overweight was also correlated with the amount of time spent in front of the tube: boys and girls were 20 to 25 percent less likely to be overweight if they watched two - three hours of TV per day, and 40 percent less likely to be overweight if they watched less than one hour of TV per day, compared to those who watched four hours or more.

Related information: Lifestyle changes - Exercise | Nutrition channel - Fitness basics

Source:  Eisemann JC, Bartee RT, Want MQ. Physical activity, TV viewing, and weight in US youth: 1999 youth risk behavior survey. Obesity Research, May 2002;10:379-385. (Abs.)