Free school lunches linked to lower obesity

IOWA STATE (US) — Free and reduced-price meals provided through the federally funded National School Lunch Program improve the health of more than 31 million children living in low-income households.

Researchers analyzed data from nearly 2,700 NSLP children (ages 6-17) taken from the 2001-04 National Health and Nutrition Examination Survey. The study finds that the lunch program reduces the prevalence of food insecurity—a situation in which an individual cannot access enough food to sustain active, healthy living—by 3.8 percent, poor general health by 29 percent, and the rate of obesity by at least 17 percent in its participants.

“Our first objective was to try to provide policymakers with the best estimates of the effects of the NSLP on the well-being of children,” says Brent Kreider, professor of economics at an Iowa State University who collaborated on the study.


“We think our results provide good evidence that the school lunch program is having generally beneficial effects on children’s health outcomes.

“Of course we can’t say that all children benefit, but it appears from our results that the prevalence of food insecurity, poor general health, and obesity would be higher without the program.”

For the study, published in the Journal of Economics, researchers used data from the National Health and Nutrition Examination Survey, conducted by the National Centers for Health Statistics, Centers for Disease Control, a program of surveys designed to assess the health and nutritional status of adults and children in the United States through interviews and direct physical examinations.

The sample included 2,693 children between the ages of 6 and 17 who were reported to be attending schools with the NSLP and residing in households with income less than 185 percent of the federal poverty line.

It’s well documented that children who qualify for free and reduced-price school lunches tend to have worse health than their fellow students.

“What is more difficult to identify is the causal role of the program itself when children are not randomly assigned into the NSLP,” Kreider says. “Parents and teachers who know that particular children are not getting adequate nutrition at home may be self-selecting such children into the program. This can make it appear that the program is ineffective when it is really just the composition of high-risk beneficiaries.”

The analysis developed new statistical methods capable of estimating causal “treatment effects” for government assistance programs when participation and eligibility are imperfectly measured. While their data came from 2001-04, Kreider says the basic structure of the NSLP and its participation rate haven’t changed much in recent years, so the conclusions are expected to be stable across time.

The most surprising result, Kreider says, was the rate of obesity reduction, which contradicts earlier research.

“We didn’t expect to find such a large effect of the NSLP on reducing the obesity rate,” Kreider says. “Theoretically, the impact of reduced-price lunches on obesity is ambiguous. Because NSLP administrators must adhere to nutritional guidelines, one might expect the NSLP to reduce obesity. But school lunches might also lead to higher caloric intakes, and possibly more fat-related calories.

“The magnitude of this effect was surprising to us, though we are not estimating an amount of weight loss but rather changes in the fraction of children above a specific threshold. This large percentage change may also reflect the somewhat small base,” he says.

Craig Gundersen, a former ISU professor of human development and family studies who now is a professor at the University of Illinois; and John Pepper, an associate professor of economics at the University of Virginia, collaborated on the research.

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