Relationship of Physical Activity and Television Watching With Body Weight and Level of Fatness Among Children Results From the Third National Health and Nutrition Examination Survey

Context. - Physical inactivity contributes to weight gain in adults, but whether this relationship is true for children of different ethnic groups is not well established. Objective. - To assess participation in vigorous activity and television watching habits and their relationship to body weight and fatness in US children. Design.-Nationally representative cross-sectional survey with an in-person interview and medical examination. Setting and Participants. - Between 1988 and 1994, 4063 children aged 8 through 16 years were examined as part of the National Health and Nutrition Examination Survey III. Mexican Americans and non-Hispanic blacks were oversampled to produce reliable estimates for these groups. Main Outcome Measures. - Episodes of weekly vigorous activity and daily hours of television watched, and their relationship to body mass index and body fatness. Results.-Eighty percent of US children reported performing 3 or more bouts of vigorous activity each week. This rate was lower in non-Hispanic black and Mexican American girls (69% and 73%, respectively). Twenty percent of US children participated in 2 or fewer bouts of vigorous activity per week and the rate was higher in girls (26%) than in boys (17%). Overall, 26% of US. children watched 4 or more hours of television per day and 67% watched at least 2 hours per day. Non-Hispanic black children had the highest rates of watching 4 or more hours of television per day (42%). Boys and girls who watch 4 or more hours of television each day had greater body fat (P