Television watching and risk of childhood obesity: a meta-analysis

Background: Over the last few decades, there has been a worldwide epidemic of childhood obesity. An important step in successful prevention in paediatrics is the identification of modifiable risk factors of childhood obesity. Many studies have evaluated the associations between television (TV) watching and childhood obesity but yielded inconsistent results. Methods: To help elucidate the role of TV watching, PubMed and Embase databases were searched for published studies on associations between TV watching and childhood obesity. Random-effects models and dose-response meta-analyses were used to pool study results. Results: Fourteen cross-sectional studies with 24 reports containing 106 169 subjects were included in the meta-analysis. Subgroup analyses were conducted by the available characteristics of studies and participants. The multivariable-adjusted overall OR of the childhood obesity for the highest vs. the lowest time of TV watching was 1.47 [95% confidence interval (95% CI): 1.33-1.62]. A linear dose-response relationship was also found for TV watching and childhood obesity (P < 0.001), and the risk increased by 13% for each 1 h/day increment in TV watching. Subgroup analysis showed a basically consistent result with the overall analysis. The association is observed in both boys and girls (for boys, OR 1.30, 95% CI 1.16-1.45; for girls, OR 1.26, 95% CI 1.11-1.41). Conclusions: our meta-analysis suggested that increased TV watching is associated with increased risk of childhood obesity. And restricting TV time and other sedentary behaviour of children may be an important public health strategy to prevent childhood obesity.