This report puts a spotlight on diet quality as a critical link between food security and nutrition. Meeting SDG 2 targets will only be possible if people have enough food to eat and if what they are eating is nutritious and affordable. The report also introduces a new analysis of the cost and affordability of healthy diets around the world, by region, and in different development contexts. It presents valuations of the health and climate-change costs associated with current food consumption patterns, as well as the potential cost savings if food consumption patterns were to shift towards healthy diets that include sustainability considerations. The report then concludes with a discussion of the policies and strategies to transform food systems to ensure affordable healthy diets, as part of the required efforts to end both hunger and all forms of malnutrition.