As Gov. Tim Walz prepares to sign the bill for universal school lunch and breakfast in Minnesota schools, what is missing from much of the public discussion is awareness of the peer-reviewed research that demonstrates beneficial impacts on students, especially those not previously eligible for the means-tested federal meals program offered to students from low-income households. Why should Minnesota taxpayers pay for free school meals for students who were not eligible for the federally-funded school lunch program? Because these are the students who may benefit the most.

The findings of two studies of the rollout of universal school meals are especially relevant as they both show achievement gains for students not previously eligible for free lunch and breakfast. Both studies employ strong research designs that include trends in student test scores before free breakfast and lunch are introduced.

One study published in 2020 looked at the adoption of universal school meals in middle schools in New York City that occurred in different years for different schools. The researchers focused on changes in test scores for individual students followed over time. They paid special attention to the comparison of students previously eligible for free meals due to their family’s low income status versus those students who were not previously being offered free meals.

After each school started to offer free meals to all students, test scores increased in both English and math. While test scores went up for both low-income students and those who were not from low-income households, the students who were not previously eligible for free meals benefited more.  The gains in test scores for the students whose families had higher incomes or were missing out on free meals due to problems with certifying eligibility was estimated to represent six to 10 weeks of learning.

Another examination of data from NYC found an improvement in attendance for kindergartners once all students were offered free meals.

More recently, a 2022 study  looked at the adoption of universal free meals by school districts across the U.S. Using district-level test scores rather than test scores on individual students, the author also found that the decision to offer universal free school meals was followed by an increase in math scores. A comparison of districts with high levels of poverty to those with lower poverty levels found that the math score gains were greater in districts that had fewer students from low-income households. In other words, school districts with fewer low-income students experienced the greatest improvements in math scores.

Without a universal system, only students whose parents satisfied the eligibility requirement and filled out the proper forms are eligible for the federal subsidy for their school meals. In some cases, entire schools have been eligible due to high levels of poverty within the school attendance area.  The research findings described here suggest that offering meals to all students can lead to improvements in test scores, with the greatest gains for students not previously receiving free lunch and breakfast.

Critics argue that the estimated $200 million per year in state funding needed to fund the expansion of the federal school meals program to include all students “would be better spent elsewhere” and that “families than can afford to pay their own way should not be eligible” for taxpayer-funded meals. But those critics seem to ignore the evidence that provision of universal meals can benefit all students, especially those above the low-income threshold.

Judy A. Temple is an economist and a faculty member at the Humphrey School of Public Affairs. She co-directs the Human Capital Research Collaborative.