Importance: The Healthy, Hunger-Free Kids Act of 2010, implemented nationwide in 2012, was intended to improve the nutritional quality of meals served in the National School Lunch Program (NSLP).
Objective: To assess whether there was an association between the Healthy, Hunger-Free Kids Act of 2010 and dietary quality of lunch for students participating in the NSLP, stratified by income.
Design, setting, participants: Serial cross-sectional study design, using National Health and Nutrition Examination Survey (NHANES) data from 2007-2008, 2009-2010, 2013-2014, and 2015-2016, of students who were surveyed in the NHANES and were attending schools participating in the NSLP. Individuals who were aged 5 to 18 years, in kindergarten through 12th grade, enrolled in a school that served school lunch, and had a reliable weekday dietary recall were included.
Exposures: The Healthy, Hunger-Free Kids Act of 2010 (prepolicy period: 2007-2010; postpolicy period: 2013-2016), with participation in the NSLP estimated based on an algorithm.
Main outcomes and measures: The primary outcome was dietary quality of intake for lunch, measured by the Healthy Eating Index-2010 (HEI-2010) score (range, 0-100; 0 indicates a diet with no adherence to the 2010 Dietary Guidelines for Americans and 100 indicates a diet with complete adherence to the guidelines).
Results: Among 6389 students included in the surveys (mean age, 11.7 [95% CI, 11.6-11.9] years; 3145 [50%] female students; 1880 [56%] were non-Hispanic white), 32% were low-income, 12% were low-middle-income, and 56% were middle-high-income students. A total of 2472 (39%) were participants in the NSLP. Among low-income students, the adjusted mean prepolicy HEI-2010 score was 42.7 and the postpolicy score was 54.6 among NSLP participants and the adjusted mean prepolicy score was 34.8 and postpolicy score was 34.1 among NSLP nonparticipants (difference in differences, 12.6 [95% CI, 8.9-16.3]). Among low-middle-income students, the adjusted mean prepolicy HEI-2010 score was 40.4 and postpolicy score was 54.8 among NSLP participants and the adjusted mean prepolicy score was 34.2 and postpolicy score was 36.1 among NSLP nonparticipants (difference in differences, 12.4 [95% CI, 4.9-19.9]). Among middle-high-income students, the adjusted mean HEI-2010 prepolicy score was 42.7 and postpolicy score 55.5 for NSLP participants and the adjusted mean prepolicy score was 38.9 and prepolicy score was 43.6 for NSLP nonparticipants (difference in differences, 8.1 [95% CI, 4.2-12.0]).
Conclusions and relevance: In a serial cross-sectional study of students, the Healthy, Hunger-Free Kids Act of 2010 was associated with better changes in dietary quality for lunch among presumed low-income, low-middle-income, and middle-high-income participants in the NSLP compared with nonparticipants.