Effects of an environmental-level school-based healthy eating intervention on school lunch participation and snack food purchases of middle school children

Increased availability of competitive foods (a la carte snack foods) during the school day parallels the rise in childhood obesity. Improvements in the school food environment are needed, though the impact on school lunch participation is unclear. This study assessed IMOVE, a school-based healthy eating initiative that provides access to alternative reimbursable lunch meals. One intervention (n=475) and one comparison (n=339) middle school in a low-income, racially diverse urban community participated. The intervention school served IMOVE meals alongside standard school lunch for a full school year. Daily school lunch and a la carte participation were assessed using coded cash register data linked to student sociodemographic information. A la carte items (similarly offered in both schools) were categorized according to nutritional quality. After introduction of IMOVE, students in the intervention school purchased significantly fewer snack foods of low nutritional quality from fall to spring term than students in the comparison school. The intervention was estimated to have a significant positive association with participation in school lunch during both terms. Although it declined, school lunch participation in the intervention school remained significantly higher than in the comparison school in both terms, suggesting IMOVE's sustainability. School-based efforts to influence obesity-related behaviors may be most effective when they change the school environment. Consistent with recent legislation, our findings support efforts to offer healthier meals that are appealing and culturally-appropriate. Such efforts do not threaten school lunch participation and may improve the nutritional quality of students' competitive snack choices.