A Review of TV Viewing and Its Association With Health Outcomes in Adults

Observational studies of the relationship between TV viewing and health outcomes (overweight/obesity, cholesterol/lipids, blood pressure/hypertension, type 2 diabetes, and metabolic syndrome) in adults are reviewed. Studies indicate that in adults, greater amounts of TV viewing are consistently associated with increased overweight risk, both cross-sectionally and longitudinally, but that results are mixed regarding the relationship between adult TV viewing and other health outcomes. It is theorized that greater TV viewing is related to increased weight status and poorer health outcomes by reducing energy expenditure, predominantly through reducing time spent in physical activity, and increasing energy intake. No randomized trials that manipulated TV viewing time measured the effects of this manipulation on diet and physical activity and then measured future health outcomes in adults. However, experimental studies, predominantly conducted in children, show relationships between TV viewing, energy intake, physical activity, and weight status, which follow the hypothesized mechanisms. Interventions targeting TV viewing in adults appear to be justified, and proposed methods for conducting these interventions, as well as potential barriers to implementing these interventions, are discussed.