Association of a television in the bedroom with increased adiposity gain in a nationally representative sample of children and adolescents.

Importance: Obesity affects health in children and adolescents. Television viewing is an established risk factor for obesity in youth. No prospective study has assessed whether a bedroom television confers an additional risk for obesity in youth.

Objective: To assess the prospective association between the presence of a bedroom television and change in body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), independent of television viewing, in a nationally representative sample of US children and adolescents.

Design, Setting, And Participants: We conducted a random-digit prospective telephone survey that captured children and adolescents from across the United States. Participants included 6522 boys and girls aged 10 to 14 years at baseline who were surveyed via telephone about media risk factors for obesity.Weighted regressions assessed adiposity at 2- and 4-year follow-up, controlling for television and movie viewing, video-game playing, parenting, age, sex, race or ethnicity, household income, and parental educational level.

Exposure: Report of having a television in the bedroom at baseline.

Main Outcomes And Measures: Age- and sex-adjusted BMI based on self-report and parent report of weight and height at 2- and 4-year follow-up.

Results: Distributions for age, sex, race or ethnicity, and socioeconomic status were similar to census estimates for the US population. Sample weighting methods accounted for higher dropout rates among ethnic minorities and those with lower socioeconomic status. Bedroom televisions were reported by 59.1%of participants at baseline, with boys, ethnic minorities, and those of lower socioeconomic status having significantly higher rates. In multivariate analyses, having a bedroom television was associated with an excess BMI of 0.57 (95%CI, 0.31-0.82) and 0.75 (0.38-1.12) at years 2 and 4, respectively, and a BMI gain of 0.24 (0.02-0.45) from years 2 to 4.

Conclusions And Relevance: Having a bedroom television is associated with weight gain beyond the effect of television viewing time. This association could be the result of uncaptured effects of television viewing or of disrupted sleep patterns. With the high prevalence of bedroom televisions, the effect attributable to this risk factor among US children and adolescents is excess weight of 8.7 million kg/y.