Evaluation of nutritional and economic impact of food waste in a school canteen

This study aimed to quantify food waste in a school canteen and evaluate its nutritional and economic impacts. Data were collected over 10 non-consecutive days during lunch in a school canteen where surpluses and leftovers were weighed. The leftovers were separated in soup and main plate components using the selective aggregate weighing method. Nutritional losses were estimated using the Portuguese Table of Food Composition, and economic losses were estimated using the prices of white-label products from a national hypermarket chain. The study evaluated 1412 meals, of which 389 were distributed to preschool children and 1023 to basic-education children. Children in basic-education were found to waste more food, with the “soup” (42.9 ± 22.1 %) and the "conduit and garnish" (39.1 ± 17.3 %) being the most discarded items. In preschool, the most wasted items were “salad/vegetables” with an average of 66.1 ± 28.7 % and "conduit and garnish" with 25.1 ± 16.9 %. Nutritionally, approximately 211 kcal, 10.3 g of fat, 15.8 g of carbohydrates, 13.1 g of protein and 1.6 g of fiber were wasted per person per day (soup and main plate). In economic terms, these losses amounted to around 0.02±0.01 euros/day for soup and 44.65±24.52 euros/day for main plate. The findings and results of this research highlight the need to improve the school canteen food services and educate the school community on the importance of eating school lunches and reducing food waste.