Nutritional combined Environmental Life Cycle Assessment of National Diets

Abstract

Innovative sustainability policies are needed to transform current global food systems in order to secure the supply of nutritious food for a growing world population, combat existing malnutrition/obesity related health problems while keeping the environmental impacts low enough so as not to transgress the planetary boundaries. Global food systems are at the heart of 12 out of 17 United Nations’ 2030 Sustainable Development Goals (SDGs). Most previous life cycle assessment (LCA) studies on food items, diets or national food consumption have focused on quantifying the environmental damage only without considering their nutritional value. However, diets low in environmental impacts might lack essential micro-nutrients whose deficiency (so called ‘hidden hunger’) affects over 2 billion people worldwide. Here we present a global scale analysis quantifying the status of national diets of 156 countries, employing six complementary indicators of nutritional quality and four indicators of environmental damage. We assess the nutritional quality of average national daily diet by comparing the intake amounts of 25 essential nutrients and several nutrients of health concern through all consumed food items with their daily-recommended values. Next, we compile the environmental footprint of national diets by combining food supply data with global literature review of LCA studies on individual food items. The results show that different countries have widely varying patterns of performance with unique priorities for improvement. Diets of high-income nations score well on essential nutrient intake indicators, but poorly on environmental and health sensitive nutrient intake indicators. Transitioning towards plant-based foods would improve environmental indicator scores for most countries but might need to be accompanied with certain micronutrient supplements that are currently supplied solely by animal-based foods. Our integrated nutrition-environmental quantitative framework can help policy-makers to design interventions, set improvement targets on specific areas while keeping track of the trade-offs with other indicators of sustainability.