Vending machine and school store (VMSS) availability and low-nutrient, energy-dense snacks and beverages in VMSS were assessed in a statewide sample of Minnesota secondary schools before and after the 2004 Reauthorization Act was implemented in 2006/2007.
The CDC School Health Profiles principal survey was collected from a representative sample of middle (n=170) and high (n=392) schools biennially from 2002 to 2010. Trends were estimated using general linear models with a logit link and linear spline modeling. Analyses were conducted in 2012.
Among high schools, VMSS (p=0.001) and sugar-sweetened beverages (p=0.004), high-fat salty snacks (p=0.001), and candy (p=0.001) in VMSS decreased from 2002 to 2008. In 2008, a change in slope direction from negative to positive occurred for all food practices and an increase in VMSS (p=0.014) and sugar-sweetened beverages (p=0.033) was seen. Among middle schools, VMSS (p=0.027), sugar-sweetened beverages (p=0.001), high-fat salty snacks (p=0.001), and candy (p=0.029) decreased from 2002 to 2010.
This study supports a link between policy and sustainable decreases in some food practices but not others and a differential effect that favors middle schools over high schools. Policy-setting is a dynamic process requiring ongoing surveillance to identify shifting trends.