Less animal protein and more whole grain in US school lunches could greatly reduce environmental impacts

Altering dietary patterns is essential to ameliorating the environmental impacts of the world food system. The U.S. National School Lunch Program shapes the consumption of America's children and adolescents, providing a meaningful opportunity to reduce dietary environmental impacts. Here, we collate life cycle inventories relevant to the National School Lunch Program and assess the environmental impacts of a representative sample of lunches served in the U.S. during the 2014–2015 school year to inform school meal policy. The mean ± SE impact per lunch was 1.5 ± 0.03 kg CO2 eq. climate change, 1.8 ± 0.03 m2a crop eq. land use, 0.055 ± 0.00 m3 water consumption, and 0.24 ± 0.05 g phosphorus eq. freshwater and 3.1 ± 0.00 g nitrogen eq. marine eutrophication. Meat products contributed the most (28–67%) to total impacts for all impact categories. Lunches in the top quintile of impacts contributed an outsized proportion to total impacts (~40%) suggesting that policy changes related to these lunches should be prioritized. To reduce the environmental impacts of the National School Lunch Program, our results support increasing whole grain requirements and providing serving size or frequency limits for beef.