TABLE 3.

Characterization of metrics related to land use applied in the research literature concerning lower–environmental impact diets

Metric	Number of studies	Reliability1	Description
Total land use	21	No	Total area of arable and nonarable land used in the production of the different foods that make up the diet
Land use × use class	11	No	Land used in the production of the different foods that make up the diet, separately reported for different land-use classes, such as land used for cropping, land used for grazing
Land use relative to a defined limit	2	No	Total land area used in the production of the different foods that make up the diet is compared with a land-availability constraint, such as national agricultural land availability, and reported as a percentage of this limit
Ecological footprint	4	No	A measure of land use required for the production of the different foods that make up the diet, as well as land required for energy production, land for sequestration of emitted greenhouse gases, and water surface area required to support fisheries; the results are expressed in global hectares—globally comparable, standardized hectares with world average productivity
Soil organic carbon deficit	1	Yes	Soil organic carbon content is considered a proxy for soil quality; the metric, which is based on generic factors for soil carbon loss for different forms of land occupation (146), has been recommended as a default method for use in life cycle assessment studies by the European Commission Joint Research Centre (147)
Biodiversity damage potential	2	Yes	Occupied land areas are classified according to type of use (e.g., annual cropping, pasture) and biome; the biodiversity damage potential is based on differences in species richness between agricultural and natural land

¹The ability to describe the relative level of environmental impact when applied in a life cycle context.