Grant: Travel Awards - Institute Community Support

BACKGROUND: The types and density of different stores and restaurants located near where people live can shape residents' food choices and subsequent risk of obesity and other chronic diseases, like diabetes and hypertension. OBJECTIVE: We investigated whether residents living in areas with a high proportion of fast-food restaurants relative to total restaurants are more likely to develop diabetes or hypertension, and whether this risk varies by volume (i.e. number) of fast-food restaurants. METHODS: We performed a population-based, retrospective cohort study in 2,940,804 adults aged 20+ who lived within walking distance (800 m) of at least one restaurant in one of five urban regions of southern Ontario. Administrative health databases were used to follow individuals from 2003 to 2013 for the development of diabetes and hypertension. RESULTS: Among younger adults (aged 20-49, 1,939,825 people in the diabetes sample and 1,830,873 people in the hypertension sample), living near more restaurants of any type was associated with slightly lower risk of developing diabetes and hypertension. However, living near a greater proportion of fast-food outlets relative to all restaurants increased the risk of both outcomes, particularly in areas with high volumes (5+) of fast-food restaurants. For both the development of diabetes and hypertension, weaker associations with fast-food exposures were observed for adults aged 50-64, and few significant associations were seen for adults aged 65+. CONCLUSIONS: Areas with the double burden of high volume of fast-food outlets and few restaurant alternatives may represent an adverse environment for the development of diabetes and hypertension, particularly among younger adults. Health promoting policies that merely target the volume of fast-food restaurants may be ineffective without also considering the overall balance of more and less healthful food retailers.