Effects of changes in lunch-time competitive foods, nutrition practices, and nutrition policies on low-income middle-school children's diets.

Background: The School Nutrition Advances Kids project tested the effectiveness of school-initiated and state-recommended school nutrition practice and policy changes on student dietary intake in low-income middle schools. Methods: Schools recruited by an application for grant funding were randomly assigned to (1) complete an assessment of nutrition education, policies, and environments using the Healthy School Action Tools (HSAT) and implement an action plan, (2) complete the HSAT, implement an action plan, and convene a student nutrition action team, (3) complete the HSAT and implement an action plan and a Michigan State Board of Education nutrition policy in their cafeteria a la carte, or (4) a control group. All intervention schools were provided with funding and assistance to make self-selected nutrition practice, policy, or education changes. Block Youth Food Frequency Questionnaires were completed by 1176 seventh-grade students from 55 schools at baseline and during eighth-grade follow-up. Nutrient density and food group changes for the intervention groups were compared to the control group, controlling for baseline dietary intake values, gender, race/ethnicity, school kitchen type, urbanization, and percent of students eligible for free or reduced-price meals. Analyses were conducted by randomization and based on changes the schools self-selected. Results: Improvements in students' nutrient density and food group intake were found when schools implemented at least three new nutrition practice changes and established at least three new nutrition policies. Students in schools that introduced mostly healthful foods in competitive venues at lunch demonstrated the most dietary improvements. Conclusions: New USDA nutrition standards for a la carte and vending will likely increase the healthfulness of middle school children's diets.