What’s more, he said, districts are almost getting these improvements free of charge. After tabulating the average price per meal in the vendor contracts—and estimating the cost of in-house school meals based on National School Lunch Program reimbursements—the study found that it cost about $222 per student per year to switch from in-house school-lunch preparation to a healthier lunch vendor that correlated with a rise of 0.1 standard deviations in the student’s test score. To put that statistic into perspective, healthier meals could raise student achievement by about 4 percentile points on average.
In comparison, it cost $1,368 per year to raise a student’s test score by 0.1 standard deviations in the Tennessee STAR experiment, a project that studied the effects of class-size on student achievement in elementary school. The paper notes that established research in the field supports the need for “lower-cost policies with modest effects on student test scores [that] may generate a better return than costly policies with larger absolute effects.”
Sean Patrick Corcoran, an associate professor of economics and education policy at New York University’s Steinhardt School of Culture, Education, and Human Development, said the study underscores the positive impact of schools serving healthier meals, and he seconded the authors’ conclusions regarding cost-effectiveness. “I've seen a number of other rigorous studies that also find a connection between healthy eating and academic performance,” he said. “Students who eat regular, healthy meals are less likely to be tired, are more attentive in class, and retain more information.” And he said some effects are almost immediate: “Even when schools serve calorie-rich food on test day, students perform better on those tests.”
In Oakland, California, Kweko Power, 15, a sophomore at Oakland High School, agreed that there’s an academic benefit to healthier meals—citing classmates who skip school lunch because it’s unhealthy and unappealing—but she believes the benefits extend beyond test scores. “When students eat healthier and better food, they get more stamina because their body doesn't have to work as hard to process what they’re eating,” she said. “When you eat and feel good, you [are] happier … and feel less cranky. While I am usually upbeat around people, I can't be myself without good food.”
For children living in areas of concentrated poverty like Oakland, good food like fruits, vegetables, and whole grains can be hard to come by. A secondary finding in the study was that contracting with a healthy lunch provider showed no evidence of reducing student obesity. And Power’s personal experience helps explain why. “In my neighborhood, we have a Lucky's [grocery store] nearby but it's expensive … it's cheaper to go to the three liquor stores that are within five blocks of that Lucky's,” she said. “When there are liquor stores that sell cheaper and unhealthier food, families tend to opt for cheaper food; they have no other choice. In areas where youth don't have access to healthier food options, you'll tend to see more obesity.”