RESUMEN
OBJECTIVE: This study aims at comparing two Italian case studies in relation to schoolchildren'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 d. 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, Ca and K 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 with 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.