A general framework for the assessment of environmental impact of food: an application to six healthy dietary patterns

In this work, the environmental impact of six worldwide spread dietary patterns (Mediterranean diet, Palaeolithic diet, Flexitarian diet, Low Carb diet, Low Fat diet and Zone diet) is assessed in terms of use of natural resources (water and ecological footprint) and GHG emissions (carbon footprint). The assessment is based on an innovative standardized system-based framework for the analysis of environmental impacts of food systems, allowing to estimate the amount of food to be produced to meet a food consumption pattern. The methodological framework is based on a multidimensional approach that allows the assessment of environmental impacts in terms of carbon footprint (Clune et al.) , water footprint (Hoekstra and Mekonnen) and ecological footprint (Global FootprintNetwork) . The structure of the framework is modular. Consumption data are converted into quantities of raw food needed to satisfy food demand (taking into account food production and transformation processes). Each raw food is then associated with the environmental impact deriving from its production, which is differentiated according to the area of production (data are currently available at national level). All six diets are recognized for their positive impact on human health and have been chosen as they allow to explore the environmental impact deriving from a different proportion of macronutrients (carbohydrates, lipids and proteins) or from different sources of protein in the dietary pattern. For each pattern, an ideal week menu has been drawn up respecting both basic criteria of the theoretical approach on which the food pattern is based, and the Italian guidelines for a healthy and correct diet. The six diets were also compared with the real Italian food consumption, estimated based on the EFSA Consumption database using as common link the FoodEx2 classification. The environmental impacts were assessed in terms of kg CO2 equivalent emitted, litres of water used and m2 needed to produce sufficient food to meet the average daily dietary income of each of the seven food regimes. The results are provided both in total terms and broken down by macronutrient or calories. A trend emerges from the analysis that links the proportion of macronutrients and protein sources with the quantity of natural resources used and the emissions produced. The results also underline the importance of a multidimensional approach to impact assessment: diets ranking is not the same according to the three footprints. The tool proves to be a useful support for policy makers and institutions involved in promoting scientific research in the agri-food sector. It allows to estimate the impact that policies in favour of the innovation of sustainable production practices, both in terms of animal and vegetable production, can have on the whole food system.