Chapters by IFPRI researchers and partners evaluate proven and innovative ways to sustainably improve diet quality and reduce malnutrition, including ways to make healthy diets more affordable, accessible, and desirable, how to improve food environments, the role of both agricultural crops and animal-source foods, and governance for better diets and nutrition, all with a major focus on the most vulnerable populations in low- and middle-income countries. Regional sections explore the diverse challenges countries face and promising policy responses for transforming food systems for sustainable healthy diets.