The paper discusses the dynamics of the double burden of malnutrition (DBM) in low- and middle-income countries (LMICs), defined as the coexistence of undernutrition and overweight/obesity. It highlights that DBM has increased significantly in the poorest LMICs, primarily due to rising overweight/obesity. Indonesia is the most affected country, but many other Asian and sub-Saharan African nations also face this issue. The increase in overweight/obesity is attributed to rapid changes in the food system, particularly the availability of cheap ultra-processed foods and beverages, and a decrease in physical activity. The paper emphasizes the need to address the drivers of these changes and implement effective policies to tackle the DBM. It also explores the epidemiology of DBM at the country and household levels, noting that the highest levels of DBM are concentrated in the lowest-income countries. The economic development and food system transitions are discussed, along with the biological underpinnings of stunting and adiposity. The paper concludes by calling for urgent action to understand and address the drivers of the new nutrition reality and to implement policies that can improve global nutrition.The paper discusses the dynamics of the double burden of malnutrition (DBM) in low- and middle-income countries (LMICs), defined as the coexistence of undernutrition and overweight/obesity. It highlights that DBM has increased significantly in the poorest LMICs, primarily due to rising overweight/obesity. Indonesia is the most affected country, but many other Asian and sub-Saharan African nations also face this issue. The increase in overweight/obesity is attributed to rapid changes in the food system, particularly the availability of cheap ultra-processed foods and beverages, and a decrease in physical activity. The paper emphasizes the need to address the drivers of these changes and implement effective policies to tackle the DBM. It also explores the epidemiology of DBM at the country and household levels, noting that the highest levels of DBM are concentrated in the lowest-income countries. The economic development and food system transitions are discussed, along with the biological underpinnings of stunting and adiposity. The paper concludes by calling for urgent action to understand and address the drivers of the new nutrition reality and to implement policies that can improve global nutrition.