Exploring the mediating roles of physical activity and television time on the relationship between the neighbourhood environment and childhood obesity.

OBJECTIVE Understanding the mechanisms by which neighbourhood environments influence childhood obesity is needed to facilitate the development of prevention strategies. The objective of this cross-sectional study was to identify the distinct types of neighbourhoods in which Canadian children reside and examine the extent to which physical activity and sedentary behaviour mediate the relationship between neighbourhood type and childhood obesity. METHODS Baseline data from the National Longitudinal Survey of Children and Youth (1994/1995) were used for this study. Latent class analysis was used to group children (age 0-11; N = 22,831) into neighbourhood types based on perceived and census-derived measures of neighbourhood attributes. A path analysis was used to determine the extent to which levels of physical activity and sedentary behaviour mediated the relationship between the resulting neighbourhood types and obesity. RESULTS Five neighbourhood types were identified. Children living in the high safety-low deprivation neighbourhood type, which had the most supportive attributes with regard to physical activity, were significanlty less likely to be obese than children living in the other neighbourhood types. Relative to the high safety-low deprivation neighbourhood, the relationship between neighbourhood type and obesity was partially mediated by physical activity and sedentary behaviour (7%-12% of total effect) among the other urban neighbourhoods, and no mediating effect was found in the rural neighbourhood. CONCLUSIONS Intervention strategies attempting to address the increased risk of obesity associated with neighbourhood environments should be tailored according to urban and rural setting and should consider taking a comprehensive approach aimed at improving a range of obesity-related behaviours.