Television viewing as a cause of increasing obesity among children in the United States, 1986-1990.

BACKGROUND AND METHODS

The prevalence of obesity among children and adolescents has increased, and television viewing has been suggested as a cause. We examined the relation between hours of television viewed and the prevalence of overweight in 1990, and the incidence and remission of overweight from 1986 to 1990 in a nationally representative cohort of 746 youths aged 10 to 15 years in 1990 whose mothers were 25 to 32 years old. Overweight was defined as a body mass index higher than the 85th percentile for age and gender.

RESULTS

We observed a strong dose-response relationship between the prevalence of overweight in 1990 and hours of television viewed. The odds of being overweight were 4.6 (95% confidence interval, 2.2 to 9.6) times greater for youth watching more than 5 hours of television per day compared with those watching 0 to 2 hours. When adjustments were made for previous overweight (in 1986), baseline maternal overweight, socioeconomic status, household structure, ethnicity, and maternal and child aptitude test scores, results were similar (odds ratio, 5.3; 95% confidence interval, 2.3 to 12.1). We also found significant relations between television viewing and increased incidence and decreased remission of overweight during this 4-year period, adjusted for baseline covariates. The adjusted odds of incidence were 8.3 (95% confidence interval, 2.6 to 26.5) times greater for youth watching more than 5 hours of television per day compared with those watching for 0 to 2 hours. Estimates of attributable risk indicate that more than 60% of overweight incidence in this population can be linked to excess television viewing time.

CONCLUSION

Television viewing affects overweight among youth, and reductions in viewing time could help prevent this increasingly common chronic health condition.