How can school meals be made more sustainable? Researchers at France's INRAE may have found the answer. After carefully reviewing the content of the dishes served in the country's school cafeterias, the scientists created a precise mathematical model to measure the best ratio for maintaining nutritional balance while reducing the carbon footprint of school meals.
Developed in collaboration with MS-Nutrition, the algorithm analyzed no less than 17 scenarios, based on a database of 2,316 school meals. The nutritional quality of the meal series was evaluated based on the mean adequacy ratio (MAR) per 2,000 kcal. The environmental impact was measured by several indicators, including greenhouse gas emissions, acidification potential on land and freshwater ecosystems, water and fossil resource use, etc.
According to the results, published in the European Journal of Nutrition, serving three vegetarian meals a week would be the best option to achieve this balance. The other two lunchtime meals could contain white meat or fish, the researchers say.
Their estimates are in line with (but go further than) France's EGalim law, introduced in 2019, which includes a requirement to serve one vegetarian dish per week in all schools.
"Updating French school nutritional guidelines by increasing the number of vegetarian meals up to 12 over 20 and serving non-ruminant meats and fish with the other meals would be the best trade-off for decreasing the environmental impacts of meals without altering their nutritional quality," conclude the study authors.
This option would therefore imply avoiding red meat as much as possible. "Reforming school catering in this way would have an impact that it is important to examine on food systems, considering in particular all the actors in the supply chains of public procurement," the researchers argue.
