Reducing the amount of meat served in school lunches and increasing servings of whole grains could help reduce the National School Lunch Program’s environmental impact while expanding the market for foods produced in more ecologically friendly ways, according to a paper published Thursday in the journal Communications Earth and Environment.
The study, conducted by researchers at the Tufts University Friedman School of Nutrition Science and Policy, considered 2.2 million lunches served at 1,207 schools during the 2014-15 school year. Lunches were assessed according to such factors as global warming potential, land use, water consumption, and contribution to marine eutrophication — dead zones caused by fertilizer runoff.
Nearly 40 percent of the environmental impacts of school lunches were attributed to just 20 percent of meals — which must include three of five core components: milk, grain, fruit, vegetables, and meat or a meat alternative. This suggests that changing just a subset of menu offerings could make an impact.
Meat products had the highest environmental footprint, in all categories. While only 2 percent of the protein served in school lunches was beef, it accounted for about half of school meals’ global warming potential, land use, and marine eutrophication potential.
The role of dairy in school lunch emissions was more mixed. While dairy was the second-largest contributor to environmental impacts after beef — because of the methane cows emit and the production of grain for feed — it also tended to be present in the lowest-impact lunches, because schools often use cheese in vegetarian meals.
Lunches’ environmental impact varied depending on which criteria researchers looked at. For example, lunches higher in fruit tended to score lower on global warming potential, land use, and marine and freshwater eutrophication, but they used comparatively more water than other lunches. Low-impact lunches emphasized dairy, whole grains, seafood, and nuts and seeds more than high-impact lunches.
The National School Lunch program fed 40 percent of U.S. children daily in 2019. Because of its size and ties to the U.S. commodity market, the program could potentially help children adopt sustainable eating habits, while also creating a market for foods produced using practices that protect soil heath and biodiversity and increase farms’ resilience to climate change. If schools served more sustainably produced grains, nuts, and seeds, school lunches could be a “win-win-win” for nutrition, the environment, and the climate, the authors wrote.
Still, they acknowledged that making these changes would require political will. Changing school nutrition standards to make school food healthier has been a long and uneven process, and efforts to incorporate sustainability into national dietary guidelines have met considerable opposition. “The outlook for this might not be strong,” they concluded.