Food waste at school. The environmental and cost impact of a canteen meal.

The challenge of increasing food demand due to population growth urges all stakeholders to act against food losses and waste, especially in light of their environmental, cost, and social impacts. In developed countries, awareness raising, and prevention are particularly important at the consumption level, where food waste mainly occurs. In this sense, public school canteens represent a unique setting, because of their capacity of conveying food habits, while sustainably managing available resources. This research assessed the environmental and cost impact of food consumption and wastage in public school canteens through a case study in Italy. It combined life cycle assessment, environmental life cycle costing, and quarter-waste visual methods. The functional unit was defined as the average meal provided by the catering service to 3-10 years old students. Primary data on type and amounts of purchased food, transport, and utilities consumption were provided by the catering service, while food waste assessment was performed in selected representative school canteens. Secondary data on background processes were mainly sourced from databases and literature. Food waste at schools represented 20-29% of the prepared meal, depending on students' age and seasonal menu. The global warming potential (GWP) of the average meal was 1.11-1.50 kg CO2-eq, mostly due to the food production impact. The meal preparation had the largest impact on costs. When considering embedded impacts, food waste was responsible for 14-18% of GWP and 6-11% of the costs. The sensitivity analysis showed promising environmental and cost reductions by introducing changes in the meal composition and preparation.