Walkable home neighbourhood food environment and children’s overweight and obesity: Proximity, density or price?

OBJECTIVES
To identify characteristics of the food environment associated with child overweight/obesity that could, if subjected to intervention, mitigate the risk of childhood overweight/obesity. We examined whether the proximity to or density of grocery and convenience stores or fast food restaurants, or the prices of healthy food options were more strongly associated with overweight/obesity risk in children.

METHODS
We collected geocoded data by residential addresses for 1,469 children aged 10-14 years and conducted a census of all food outlets in Saskatoon. The Nutrition Environment Measures Survey (NEMS)-Stores and the NEMS-Restaurants were used to measure availability, quality and relative price of healthy food items in stores and restaurants. Children's weight status was calculated on the basis of measured height and weight. Logistic regression was used to test the associations between overweight/obesity and food environment variables.

RESULTS
Within an 800 m walking distance from home, 76% of children did not have access to a grocery store; 58% and 32% had access to at least one convenience store or one fast-food restaurant respectively. A significantly lower odds of overweight/obesity was associated with lower price of healthy food items/options in grocery stores (odds ratio [OR] = 0.87, 95% confidence interval [CI] 0.77-0.99) and fast-food restaurants (OR = 0.97, 95% CI 0.95-0.99) within walking distance of home. Neither the distance to the closest food outlet nor the density of food outlets around children's homes was associated with odds of overweight/obesity.

CONCLUSIONS
Improving economic access to healthy food in food outlets or fast-food restaurants is one strategy to counter childhood overweight/ obesity.