hildhood obesity has become a critical public health issue in Canada, as rates have tripled over the past three decades. 1 Over one in four Canadian children are either overweight or obese (17% and 9% respectively). 2 The increased prevalence of childhood obesity has been linked to the concurrent rise of physical health problems normally associated with adults, including Type 2 diabetes, hypertension, heart disease and pulmonary diseases, as well as socio-psychological afflictions such as discrimination, behavioural problems, negative self-esteem, anxiety and depression. [3][4][5][6] A rapidly expanding avenue of research suggests that rising rates of obesity are due not only to individual-level factors (i.e., genetics), but also to characteristics of our local built environments that may be encouraging or discouraging the healthy diets or active lifestyles associated with healthy body weights. [7][8][9][10] Previous research has confirmed that obesity is linked to the consumption of energy-rich, fast foods. 11 Large-scale US studies have found that adult obesity rates are positively associated with the density of neighbourhood fast-food outlets 12 and convenience stores. 13 Much of the emphasis on the link between food and children's health focuses on advertising 14 or food policies within schools; 15-17 however, some policy-makers and public health professionals are shifting their focus to the food environments surrounding schools, as new research indicates that many children visit food retailers on their way to and from school, mostly filling up on high-sugar or high-fat, energy-dense foods. 18 Several studies have shown that fast-food outlets are more prevalent near schools 19,20 and in low-income neighbourhoods, 21,22 suggesting that these vulnerable populations may be at heightened risk of developing poor eating habits as a result of increased exposure to unhealthy foods. Furthermore, it has been shown in London, ON,