Global Epidemiological Patterns and Disease Burden of MASLD, MetALD, and ALD

The 2023 multisociety Delphi consensus redefined the nomenclature for steatotic liver disease (SLD) by replacing nonalcoholic fatty liver disease (NAFLD) with metabolic dysfunction-associated steatotic liver disease (MASLD) and introducing metabolic dysfunction and alcohol-associated liver disease (MetALD) and alcohol-associated liver disease (ALD). This revised framework is expected to enhance epidemiological surveillance, phenotyping of SLD, and public health interpretation. This review summarizes contemporary literature on the global epidemiology, disease burden, and comparative outcomes of MASLD, MetALD, and ALD. MASLD remains the most prevalent SLD subtype, affecting approximately 30%-40% of adults worldwide, with a rising burden over time. MASLD rapidly increases in regions with lower sociodemographic indices. MetALD affects an estimated 2%-8% of adults and represents an important overlap phenotype, although its prevalence is likely underestimated due to frequent underreporting of alcohol intake. ALD has a lower prevalence but contributes disproportionately to higher liver-related morbidity and mortality and is reported to have a marked regional variation linked to patterns of alcohol consumption. SLD has emerged as a major global epidemic, with MASLD imposing the greatest population burden and MetALD/ALD disproportionately contributing to severe liver-related outcomes. Across SLD phenotypes, cardiovascular disease is a major cause of death in non-cirrhotic disease, while liver-related outcomes show a gradient associated with alcohol exposure. Significant epidemiologic limitations include heterogeneity in the steatosis assessment methods, limited availability of cardiometabolic criteria, and reliance on self-reported alcohol consumption. Mitigating this growing burden of SLD requires public health policies that incorporate metabolic risk prevention, regulation of alcohol consumption, and early risk stratification.