Association Between State Laws Governing School Meal Nutrition Content and Student Weight Status: Implications for New USDA School Meal Standards

Study Questions:

Are stronger school meal nutrition standards inversely associated with adolescent weight status?


This was a quasi-experimental study design conducted within public schools across the country. Student data were obtained from the Early Childhood Longitudinal Study, a nationally representative sample. This analysis included data collected in 2007, when students were in eighth grade. Students were categorized by type of school lunch they usually obtained (free/reduced price, regular price, or none). Among the 7,050 public school students who participated in 2007, students were excluded if their principal reported that no students participated in lunch programs, they resided in a state with fewer than five observations, or they were missing data on school lunch programs, height or weight, lunch participation, or other covariates, leaving 4,870 students from 40 states. Missing data were equally common in states with different school meal laws, but more common among boys, racial/ethnic minorities, and students who resided in urban areas, were of low socioeconomic status (SES), or were obese. The intervention examined was state laws governing school meal nutrition standards. States with standards that exceeded US Department of Agriculture (USDA) school meal standards were compared with states that did not exceed USDA standards. The parameter of interest was the interaction between state laws and student lunch participant status, i.e., whether disparities in weight status between school lunch participants and nonparticipants were smaller in states with stricter standards. The primary outcome of interest was body mass index percentile and obesity status for the students.


A total of 4,870 eighth grade students were included in this analysis. Students who received free/reduced-price lunches tended to be of lower SES, were less likely to be non-Hispanic white, and were less likely to live in suburban areas than students who purchased full-price lunches at school or those who did not obtain lunch at school. Students in states that exceeded USDA standards were more likely to be Hispanic, of a lower SES, and located in suburban areas than students in states without such laws. States that exceeded USDA standards had slightly higher mean obesity prevalence (age 10-17 years) and poverty rate, but also had higher median income and higher percentage of adults with a bachelor’s degree. In states that exceeded USDA standards, the difference in obesity prevalence between students who obtained free/reduced-price lunches and students who did not obtain school lunches was 12.3 percentage points smaller (95% confidence interval [CI], -21.5 to -3.0) compared with states that did not exceed USDA standards. Likewise, differences in mean body mass index percentile between those student populations were 11 units smaller in states that exceeded USDA standards (95% CI, -17.7 to -4.3). There was little evidence that students compensated for school meal laws by purchasing more sweets, salty snacks, or sugar-sweetened beverages from other school venues (e.g., vending machines) or other sources (e.g., fast food).


The investigators concluded that stringent school meal standards that reflect the latest nutrition science may improve weight status among school lunch participants, particularly those eligible for free/reduced-price lunches.


This study supports the need for updating school lunch programs to reflect current understanding of healthy nutrition for school-age children. The school day is an optimal time to intervene on health behaviors; these data support prior studies, which suggest that school-based interventions and policies can make real differences in the health of our children.

Keywords: United States Department of Agriculture, Students, Body Weight, Beverages, Hispanic Americans, Health Behavior, Fast Foods, Body Mass Index, Schools, Obesity, Nutritional Sciences, Snacks, Lunch, Poverty

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