Associations of Television Content Type and Obesity in Children

Obesity continues to be a major public health concern for America’s children, with obesity rates for preschool children tripling in the past 30 years and quadrupling for children aged 6 to 11 years.1 Television viewing has been shown to be associated with obesity cross-sectionally2–8 and in longitudinal data in many,9–14 but not all,15–17 studies. Comprehensive literature re-views of these disparate results conclude that the association between television viewing and obesity is on average small, but negative.18,19 A constructive way to reconcile the dispa-rate findings is to recognize that different kinds of television content may exert different effects on obesity. Television might lead to obesity through 3 primary pathways20,21: by displacing time that would otherwise be spent in physical activity; by promoting eating while viewing, which may foster both lower-quality and higher-quantity food intake; and by exposing children to food advertising, which adversely affects their diets. These pathways have quite different impli-cations for the ways different kinds of televi-sion content might affect obesity. The hy-potheses involving displacement of physical activity and eating while viewing suggest that all types of television have an equal and significant effect on obesity. If the adver-tising hypothesis is more accurate, only com-mercial television viewing should be associ-ated with obesity and not noncommercial television or DVD viewing. Of course, all pathways might be operative, in which case we would expect significant associations between all types of content and obesity but associa-tions of greater magnitude for commercial content. A review of the literature on the role of media in childhood obesity identified no scholarly articles analyzing the associations of different types of television content with obe-sity status in children.22 We used nationally representative longitudinal data to analyze the effects of different kinds of television content on body mass index (BMI)