The sustainability of diets in sub-Saharan Africa: Synergies and tradeoffs between human health and the environment

Sub-Saharan Africa (SSA) faces unique food security and sustainability challenges. The diets in SSA are insufficient on average, but how they compare across various population segments in terms of nutritional adequacy and environmental footprints is not sufficiently understood. Life cycle assessment (LCA) of diets can be useful, but existing life cycle inventories mostly refer to high-income countries. Hence, data and methodological adjustments are needed to better reflect local production and consumption conditions. Here, we enhance LCA by tailoring it to local contexts, providing the first comprehensive LCA analysis of diets in SSA, and combining this with nutritional analysis. We assess global warming, land use, and water consumption impacts, as well as nutritional adequacy of diets in Ethiopia, Ghana, and Nigeria. We also analyse associations between the nutritional and environmental dimensions across population segments with a particular focus on the effects of rising incomes and urbanization. While we find variation between countries, average diets in SSA have much lower environmental impacts than the Western dietary pattern in high-income countries. Rising incomes and urbanization in SSA are associated with improved nutrient adequacy, but also with larger environmental footprints, pointing at sustainability tradeoffs under current conditions. These tradeoffs may be reduced through developing and implementing dietary patterns that optimize nutritional, environmental, and social goals. In addition, productivity and efficiency gains in food supply chains are needed to ensure a variety of healthy food choices are locally available and affordable.