Increasing homogeneity in global food supplies and the implications for food security

TLDR

The narrowing of crop species diversity in global food supplies is a potential threat to food security, yet global changes have not been quantified. This study evaluates 50‑year trends in crop species richness, abundance, and composition in national food supplies worldwide. We analyzed national food supply data to assess changes in crop commodity richness, abundance, and compositional evenness over five decades. National food supplies expanded in calories, protein, fat, and weight, shifting toward energy‑dense foods, while the number of crop commodities rose but their relative contributions became more even, resulting in greater global homogeneity driven by cereals and oil crops and increasing interdependence and urgency for nutrition development.

Abstract

The narrowing of diversity in crop species contributing to the world's food supplies has been considered a potential threat to food security. However, changes in this diversity have not been quantified globally. We assess trends over the past 50 y in the richness, abundance, and composition of crop species in national food supplies worldwide. Over this period, national per capita food supplies expanded in total quantities of food calories, protein, fat, and weight, with increased proportions of those quantities sourcing from energy-dense foods. At the same time the number of measured crop commodities contributing to national food supplies increased, the relative contribution of these commodities within these supplies became more even, and the dominance of the most significant commodities decreased. As a consequence, national food supplies worldwide became more similar in composition, correlated particularly with an increased supply of a number of globally important cereal and oil crops, and a decline of other cereal, oil, and starchy root species. The increase in homogeneity worldwide portends the establishment of a global standard food supply, which is relatively species-rich in regard to measured crops at the national level, but species-poor globally. These changes in food supplies heighten interdependence among countries in regard to availability and access to these food sources and the genetic resources supporting their production, and give further urgency to nutrition development priorities aimed at bolstering food security.