Legumes as a sustainable source of protein in human diets

Dietary protein production from animals is a major source of greenhouse gas emissions, water use, and defor-estation. Legumes are a rich source of protein but currently comprise a minor part of most human diets. Worldwide, the average consumption of legumes and meat is 21 and 112 g/person/day, respectively. Legumes are part of traditional diets in most cultures, have low greenhouse gas and water footprints, enrich the soil through nitrogen fixation, are inexpensive, and comprise a sustainable source of protein. Challenges to increased legume usage include large fluctuations in crop yields and lower profitability compared with other crops. Greater investment in legume breeding and heightened consumer awareness may facilitate a future shift to legumes as a major source of dietary protein.