Carbon Footprint of Seasonal Meals: The Case of School Canteens

School canteens may play an important role in promoting sustainable diets based on the selection of seasonal meals and nutritional values. In this study, the life cycle assessment method was applied to evaluate the environmental performance, in terms of global warming, related to the life cycle of four seasonal menus supplied to school canteens. Furthermore, the aim is also to understand how environmental sustainability may be linked to strategic choices oriented to seasonal menus and nutritional values of ingredients. The functional unit is referred to as “one seasonal menu delivered to a school canteen,” while system boundaries are defined, including three different phases: (1) ingredient production and transport, (2) meal preparation, and (3) meal delivery. The results underscore that, in all the investigated menus, ingredient production (phase 1) causes the main contribution to the impacts, followed by cooking processes (phase 2). Furthermore, high variability is identified when the impacts of ingredients are compared to their nutritional values, and an improvement in global warming performance is identified when seasonal food products are adopted. The study also points out the need for more specific frameworks aimed at helping decision-makers in choices regarding sustainable and nutritionally balanced diets.