ObjectivesProtein-energy malnutrition poses a serious medical problem worldwide. This study aims to describe the global burden, trends, and health inequalities of protein-energy malnutrition and forecasts for future prevalence. Study designThis was a comprehensive analysis based on data provided by the Global Burden of Disease Study 2019. MethodsData were obtained from the Global Health Data Exchange query tool, including prevalence, deaths, disability-adjusted life years (DALYs) and sociodemographic index (SDI). The estimated annual percentage changes were calculated to evaluate temporal trends. We quantified cross-country inequalities in protein-energy malnutrition burden and predicted the prevalence number and rate to 2044. ResultsGlobally, there were 147,672,757 (130,405,923 to 167,471,359) cases of protein-energy malnutrition in 2019, with 212,242 (185,403 to 246,217) deaths. Eastern Sub-Saharan Africa had the highest age-standardised death and DALY rates in 2019. From 1990 to 2019, the global age-standardised prevalence rate of protein-energy malnutrition showed an upward trend, while the age-standardised death rate showed a downward trend. A significant decline occurred in SDI-related health inequality, from 2126.1 DALYs per 100,000 persons between the poorest and richest countries in 1990 to 357.9 DALYs per 100,000 persons in 2019. There was a trend of decreasing age-standardised death and DALY rates along with increases in the SDI. Frontier analyses showed that there is much room for improving the current situation of protein-energy malnutrition in some countries. In the next 35 years, the prevalence of protein-energy malnutrition will continue to increase. ConclusionAlthough the disease burden of protein-energy malnutrition has greatly decreased since 1990 and health inequalities between countries are shrinking, the prevalence in Asian and African countries may continue to increase. Focussing on regional differences and strengthening the nutritional intake of people in underdeveloped areas are necessary to reduce future burdens.