Changes in association between school meals and children's dietary quality during implementation of the Healthy, Hunger-Free Kids Act of 2010

The Healthy, Hunger-Free Kids Act of 2010 raised standards for foods sold in US schools. The aims of this paper are to estimate policy effects on dietary quality of US school-aged children, and determine if effects differed by free/reduced-price meal eligibility or age group. We estimated within-child associations between school food consumption and dietary quality (using Health Eating Index - 2010), by comparing two 24-hour dietary recalls per child from the 2007-2016 National Health and Nutrition Examination Survey. We used inverse probability weighting to account for population changes during this period. We scaled changes of association (implementation period versus pre-passage) by proportion of energy from school foods. School foods were 10% of annual calories, 33% on days when children ate school foods. Each percentage point of energy from school foods was associated with 0.08 more Healthy Eating Index points during implementation than pre-passage. The scaled estimated effect of policy implementation on annual dietary quality is 0.84 Healthy Eating Index points, 2.8 points on days when children eat school foods. Estimated effects were slightly greater for children eligible for free/reduced-price meals and high school-aged children, though confidence intervals include zero. The results indicate that targeted policies can improve children9s dietary quality.