The sustainability of diets: Current understanding and shortcomings

Abstract

Food production contributes to 21–37% of global greenhouse-gas emissions, 70% of water withdrawals and occupies more than 40% of lands. Despite one third of the food produced is wasted, access to food and healthy diets are not guaranteed to all. Sustainable nutrition investigates how to transition to healthy and sustainable food consumption. This review provides the most updated findings on sustainable diets by summarizing the most recent studies on its dimensions, the metrics used to determine and describe it and the shortcomings in this field. The literature reports the higher value of greenhouse gas emissions and land use for animal-source diets, either for self-selected diets or recommended dietary patterns. Water footprint of diets can vary a lot across countries and dietary patterns and is dependent on trading and food origin. The environmental impacts of diets have been merged to nutrient density indexes and morality rate, but indicators are not yet standardized and the literature presents a research gap in this field.