The key product of a sustainable food system is healthier diets. Important aspects of healthy diets are quality, quantity, frequency, diversity, and safety. Poor diets are key contributors to food insecurity and various forms of malnutrition: undernutrition, micronutrient deficiencies, & overweight and obesity. Conversely, healthier diets are essential in preventing and reducing all forms of malnutrition as well as diet-related Non-Communicable Diseases (NCDs) such as type 2 diabetes, cardiovascular diseases (including hypertension and stroke), and several cancers. Some of our research interests and focus areas within this theme include determinants of child undernutrition; adolescent health; nutrition of poor consumers; diets transformation; nutrition transition and its effects; supermarket effects on diets and overweight/obesity; consumption of Ultra-Processed Foods (UPF) and effects on nutrition and health; food prices and cost of diets; and NCDs prevention.