Features of neighbourhood environments associated with obesity and related health behaviours in children: using multiple statistical approaches to identify obesogenic environments

Background: Childhood obesity currently poses a major public health challenge worldwide. In an attempt to identify potential targets for population-based prevention strategies, neighbourhood environments are increasingly being investigated in relation to childhood obesity and its behavioural precursors. However, research to date is largely beset by inconsistencies in findings. Purpose: The overarching goal of this thesis is to investigate the contribution of different features of neighbourhood environments in relation to obesity and antecedent behaviours in children. Specific objectives are: 1) To examine associations between children’s residential and school neighbourhood food environments and their dietary intake and behaviours;  2) To examine shared exposure to features of residential neighbourhoods in relation to obesity among family triads (child, mother, and father) and among individual family members; 3) To identify specific combinations of individual, familial, and neighbourhood risk factors that best predict obesity in children, and determine whether these risk factor profiles also predict 2-year changes in obesity. Methods: Data were drawn from the QUALITY Cohort, a Quebec-based study of 630 children aged 8-10 years at baseline with a parental history of obesity. Baseline residential neighbourhood environments of 512 participants living in the Montreal Metropolitan Area were characterised using: 1) geographically linked census and administrative data computed for road network buffers centered on the residential and school locations; and 2) in-person neighbourhood observations conducted within the participants’ residential neighbourhoods. Neighbourhood measures included characteristics of the built, social, and food services environments. Obesity was determined using the body mass index (BMI) computed from measured weight and height at baseline and at follow up. Diet was measured using three 24-hour diet recalls at baseline. Different types of analyses were used including generalised estimating equations, multilevel regressions, and recursive partitioning. Results: Findings point to specific neighbourhood features that are associated with childhood obesity and diet. Most notably, increased availability of convenience stores and fast food restaurants within residential and school neighbourhoods is associated with poorer diets among children. High street-level traffic and low neighbourhood prestige and urban development in residential neighbourhoods are associated with obesity among family triads. Lastly, findings suggest that obesogenic neighbourhood environments characterised by socioeconomic disadvantage, fewer parks, and more convenience stores jointly predict childhood obesity within unique combinations of individual and familial risk factors.  Conclusion: This thesis contributes to the literature on neighbourhood environments and childhood obesity by considering the influences of both residential and school neighbourhoods as well as familial environments, by objectively characterising neighbourhoods, and by using innovative statistical approaches. Findings furthermore support the notion that obesity prevention efforts should target multiple risk factors of childhood obesity within the built, social, and family environments of children.

Keyphrases: body mass index, built environment, children, diet, family environment, food environment, neighbourhood, obesity, physical activity, QUALITY study