Abstract
Non-alcoholic fatty liver disease (NAFLD) has become the world’s largest chronic liver disease in the 21st century, affecting 20%–30% of the world’s population. As the epidemiology, etiology, and pathogenesis of NAFLD have been studied in-depth, it has been gradually recognized that most patients with NAFLD have one or more combined metabolic abnormalities known as metabolic syndrome. In 2020, the international expert group changed the name of NAFLD to metabolic-associated fatty liver disease (MAFLD) and proposed new diagnostic criteria for MAFLD and MAFLD-related liver cirrhosis, as well as the conceptual framework of other cause-related fatty liver diseases to avoid diagnosis based on the exclusion of other causes and better reflect its pathogenesis. However, there are still many ambiguities in the term, and changing the name does not address the unmet key needs in the field. The change from NAFLD to MAFLD was not just a change of definition. The problems and challenges are summarized as follows: epidemiology, children, rationality of “metabolism,” diagnostic criteria, double/multiple causes, drug discovery, clinical trials, and awareness raising. Metabolic-associated fatty liver disease has complex disease characteristics, and there are still some problems that need to be solved.