The role of beverage consumption, physical activity, sedentary behavior, and demographics on body mass index of adolescents

The percentage of US adolescents who are overweight or at-risk of overweight has increased over the past 20 years. Using data from the third National Health and Nutrition Examination Survey 1988–1994, multivariate regression models of body mass index (BMI) for adolescent males and females aged 12–16 years were developed to examine the relative importance of demographics, beverage consumption, physical activity, and sedentary behavior for maintaining a healthy body weight. The models explained between 11% and 19% of the variance in BMI. Demographic characteristics accounted for roughly one-half of the explained variance in the models. Age was positively associated with BMI for males and females. Family income had a negative association with BMI for females, but no association with BMI for males. The variables for race/ethnicity and region were only occasionally statistically significant. A strong negative association was found between BMI and participation in team sports or exercise programs for both males and females. The estimate of the relationship between television viewing and BMI was positive but not statistically significant. Consumption of regular carbonated soft drinks (RCSD) and fruit drinks/ades—two beverages widely hypothesized to be positively associated with BMI—were not statistically significant in any of the models. Consumption of diet carbonated soft drinks was very low and was positively associated with BMI for females but not for males. The potential impacts of increasing participation in teams or exercise programs, reducing television viewing, and reducing RCSD consumption on BMI were examined. Increasing participation in teams or exercise programs consistently had the largest impact on reducing predicted BMI. The impact of reducing television viewing had the next largest impact. Reducing consumption of RCSD had the smallest impact. Policies that revitalize physical activity and physical education programs for all students—not just student athletes—and educational efforts that discourage sedentary behavior will be far more successful in combating overweight than an undue focus on beverage consumption.