Association between physical activity, diet, television/video viewing, computer use, and weight status among U.S. adolescents

Controversy exists about the relative contribution of physical activity, dietary intake, television/video viewing, and computer use with weight status among adolescents and whether these associations differ by race/ethnicity or gender. Teasing apart such contributions is needed to prioritize targeting of health policies and programs to specific risk factors and to specific gender and race/ethnicity groups. The objectives of this study were to determine the relative contribution of physical activity, total energy intake, total fat intake, fiber intake, television/video viewing, and computer use to weight status among adolescents in the United States, as well as to determine if the association between physical activity and weight status differs by gender or race.

Secondary analyses of the nationally representative NHANES (2003-2006) cross-sectional surveys were conducted among 2,136 U.S. adolescents. After controlling for the effect of confounders, multinomial logistic regression models indicated that television/video viewing was significantly associated with both at-risk for overweight (OR=1.57; 95% C.I.=1.1, 2.63) and overweight (OR=1.84; 95% C.I.=1.24, 2.69), while television/video viewing (OR=1.84; 95% C.I.=1.24, 2.69), physical activity (OR=0.75; 95% C.I.=0.59, 0.95), and fiber intake (OR=0.96; 95% C.I.=0.92, 0.99), were significantly associated only with overweight.

Physical activity was found to be an important factor associated with overweight, in addition to television/video viewing, and fiber intake. Apart from physical activity and nutrition interventions, future studies should also develop interventions that target a reduction in television/video time. Multiplicative interaction was not found significant for physical activity and gender or physical activity and race, suggesting universal overweight prevention policies and programs should be delivered.