Fast-food Chain Outlet Density near High Schools Is Associated with Adolescent Junk Food Purchasing

Background: Policies and programs aimed at mitigating the availability of unhealthy food outlets near schools might be a promising strategy to improve dietary intakes and reduce obesity in schoolchildren. Australian evidence is scarce with regards to how school children interact with food outlets near schools and whether the 'food environment' (i.e., the type, location, and number of food outlets within a geographic location) near schools is associated with student food purchasing. The aim of this study was to investigate the relationship between frequency of secondary school students' discretionary food purchasing from food outlets near their school and the types and number of food outlets present in the surrounding food environment. Methods: Perth (Western Australia) secondary school students reported their frequency of discretionary food purchases from food outlets near their school (17 schools, n = 2,389 grade 7-12 students). Food outlet availability was sourced from Local Governments and geocoded. A mixed-effects model was used in analyses. Results: Almost half (45%) of students purchased discretionary foods from food outlets near their school on a weekly-or-more basis. For every additional top-ranking fast-food chain (i.e., McDonalds, KFC, Hungry Jacks, Red Rooster) within 400m, 800m, and 1km of a school, there was a significant increase in the frequency of student purchasing of discretionary foods from an outlet near their school (p < 0.05). There was no evidence that the number of fast-food outlets, supermarkets, convenience stores, other snack/beverage stores and fruit and vegetable outlets near schools were associated with discretionary food purchasing. Conclusions: The availability of fast-food chains appear to be a key driver of students' discretionary food purchasing from food outlets near schools. Interventions restricting major chain fast-food outlets near schools may help curtail adolescent's consumption of discretionary foods.