Moving beyond calories and protein: Micronutrient assessment of UK diets and land use

In the next decades, an increasing demand for the amount and types of food will have to be produced on decreasing per-capita available land areas, while the current environmental impact of agriculture also needs to be reduced. This confluence of the need for an adequate and healthy diet for everyone and the need for a sustainable use of land requires new agricultural metrics that consider human nutrition as a primary objective of agriculture. In this case study for the United Kingdom, we link agricultural yield statistics with UK-specific food composition data to analyse the land use efficiency of food items for 23 different nutrients. We show that, from a land use perspective, roots & tubers and vegetables are the most land-efficient producers for these 23 nutrients. Our results indicate further that, across all 23 nutrients, roots & tubers and vegetables deliver enough nutrients to feed a median number of 43 and 42 people per hectare for one year, respectively, while a hectare of cereals feeds a median of 21 people. Eggs, the most land-efficient animal product, only feed a median of four people per hectare. We conclude that a focus on a wide range of nutrients may lead to different conclusions about an efficient use of land compared to previous analyses that tend to only consider dietary energy and protein.