Rethinking noninvasive steatosis indices: Structural limitations and misclassification across the body mass index spectrum

The rebranding of nonalcoholic fatty liver disease (NAFLD) to metabolic dysfunction-associated steatotic liver disease (MASLD) has shifted the clinical focus toward underlying metabolic drivers. This necessitates a re-evaluation of noninvasive diagnostic tools to better align with metabolic dysfunction as the primary driver of hepatic steatosis. Commonly used indices, including the fatty liver index, hepatic steatosis index, and NAFLD liver fat score, were originally developed to estimate liver