Food affordability and nutritional values within the functional unit of a food LCA. An application on regional diets in Spain.

This study assesses the environmental impacts associated with current regional-average diets in Spain, and it evaluates the environmental benefits of adopting a diet based on the National Dietary Guidelines (NDG). To establish a fair method for diets’ comparison among the different regions, a novel functional unit (FU), that considers both the nutritional and the socio-economic dimensions, was developed. Diets in north–western regions have larger impacts due to the high caloric energy and ruminant meat intake, as well as for being less affordable. The adoption of the NDG-based diet can potentially reduce the environmental impacts (GHG emissions, blue water footprint and land use) between 15 and 60% of current regional eating patterns. This study highlights the importance of properly selecting the FU, and integrating the concept of food affordability within the FU in diet LCAs.