Objective: To assess change in the 4-year prevalence (2006-2009) of the use of food in school fundraising and as rewards and incentives for students, following implementation of federal legislation in the USA in 2006.
Design: Serial cross-sectional design using trend analysis to assess school-level data collected over four consecutive years from 2006/2007 to 2009/2010.
Setting: Minneapolis/St. Paul, MN.
Subjects: Convenience sample of middle and high schools participating in two longitudinal, aetiological studies that examined youth, their environment and obesity-related factors.
Results: A significant and sustained decrease was demonstrated in the use of low-nutrient, energy-dense foods in school fundraising activities and the use of food and food coupons as rewards and incentives by teachers and school staff.
Conclusions: Results support the utility of policy and legislative action as a tool for creating healthy, sustainable environmental change.