Metabolic dysfunction-associated steatotic liver disease (MASLD) affects a significant portion of the global adult population, with a substantial number of cases occurring in individuals with normal body mass index (BMI). This article provides an overview of the definition, epidemiology, pathogenesis, and clinical outcomes of MASLD in lean individuals, as well as updates on current management strategies. MASLD in lean individuals is characterized by a more favorable metabolic risk profile compared to non-lean counterparts, but they still experience significant complications, including liver and non-liver issues. The pathogenesis of MASLD in lean individuals involves both non-modifiable polygenic factors and modifiable lifestyle-related factors, such as unhealthy dietary intake, gut dysbiosis, and low physical activity. Genetic testing, particularly whole genome sequencing, may help uncover monogenic disorders in lean individuals with MASLD. Management strategies focus on dietary modifications, exercise, and metabolic risk factor modification, with a recent emphasis on improving insulin resistance rather than weight loss. The article also highlights the importance of screening for MASLD in lean individuals, emphasizing the need to assess metabolic health rather than solely relying on BMI.Metabolic dysfunction-associated steatotic liver disease (MASLD) affects a significant portion of the global adult population, with a substantial number of cases occurring in individuals with normal body mass index (BMI). This article provides an overview of the definition, epidemiology, pathogenesis, and clinical outcomes of MASLD in lean individuals, as well as updates on current management strategies. MASLD in lean individuals is characterized by a more favorable metabolic risk profile compared to non-lean counterparts, but they still experience significant complications, including liver and non-liver issues. The pathogenesis of MASLD in lean individuals involves both non-modifiable polygenic factors and modifiable lifestyle-related factors, such as unhealthy dietary intake, gut dysbiosis, and low physical activity. Genetic testing, particularly whole genome sequencing, may help uncover monogenic disorders in lean individuals with MASLD. Management strategies focus on dietary modifications, exercise, and metabolic risk factor modification, with a recent emphasis on improving insulin resistance rather than weight loss. The article also highlights the importance of screening for MASLD in lean individuals, emphasizing the need to assess metabolic health rather than solely relying on BMI.