Urban sprawl and childhood obesity.

Urban sprawl is thought to be a risk factor for childhood obesity primarily because the physical environment it creates discourages children's physical activity while encouraging their sedentary behavior. However, there has not been any review on the association between urban sprawl and childhood obesity. This study filled this research gap by comprehensively reviewing literature focusing on associations between urban sprawl and weight-related behaviors and outcomes among children and adolescents. Only two longitudinal and three cross-sectional studies conducted in two countries were identified. Sample sizes ranged from 2324 to 129 781. Four studies used weight status, and only one study used both behaviors and weight status as outcome variables. All positive, negative, and non-significant associations were reported. This review could not identify a clear association between urban sprawl and childhood obesity. More longitudinal studies are needed for in-depth analyses on this important topic in more regions, which would be important not only for public health guidelines but also for research, practice, and policies in urban planning.