Nutritional, environmental and economic implications of children plate waste at school: a comparison between two Italian case studies

Objective: This study aims at comparing two Italian case studies in relation to school children's plate waste and its implications, in terms of nutritional loss, economic cost, and carbon footprint. Design: Plate waste was collected through an aggregate selective weighting method for 39 days. Setting: Children from the first to the fifth grade from four primary schools, two in each case study (Parma and Lucca), were involved. Results: With respect to the served food, in Parma the plate waste percentage was lower than in Lucca (p<0.001). Fruit and side-dishes were highly wasted, mostly in Lucca (>50%). The energy loss of the lunch meals accounted for 26% (Parma) and 36% (Lucca). Among nutrients, dietary fibre, folate and vitamin C, calcium and potassium were lost at most (26-45%). Overall, after adjusting for plate waste data, most of the lunch menus fell below the national recommendations for energy (50%, Parma; 79%, Lucca) and nutrients, particularly for fat (85%, Parma; 89%, Lucca). Plate waste was responsible for 19% (Parma) and 28% (Lucca) of the carbon footprint associated to the food supplied by the catering service, with starchy food being the most important contributor (52%, Parma; 47%, Lucca). Overall, the average cost of plate waste was 1.8 €/kg (Parma) and 2.7 €/kg (Lucca), accounting respectively for 4% and 10% of the meal full price. Conclusion: A re-planning of the school meals service organisation and priorities is needed to decrease the inefficiency of the current system and reduce food waste and its negative consequences.