Fatty liver is a lifestyle-related disease with a prevalence of approximately 30% of adults. In recent years, liver cancer from fatty liver disease has increased worldwide and has become a major health problem. Many factors are involved in the carcinogenesis of fatty liver disease, which is distinct from that of virus hepatitis-related liver cancer. In 2023, the nomenclature of NAFLD/NASH was changed to MASLD/MASH, which was led by the initiative of the AASLD, EASL, and ALEH. Within this, the group of patients with steatotic liver disease who drink moderate amounts of alcohol was defined as MetALD, which allowed us to study the combined effects of cardio-metabolic risk factors and moderate alcohol consumption on liver disease progression. In this symposium, MASLD/MASH is redefined as a progressive liver disease with steatosis and metabolic dysfunction, and the impact of the nomenclature change will be discussed on MetALD from the perspective of epidemiology, pathogenesis, diagnosis, and treatment development in Japan and the US.