Fatty Liver Index vs. Biochemical–Anthropometric Indices: Diagnosing Metabolic Dysfunction-Associated Steatotic Liver Disease with Non-Invasive Tools

Background/Objective: Metabolic dysfunction-associated steatotic liver disease (MASLD) has emerged as a significant global burden, attributed to its increasing prevalence and strong correlation with metabolic syndrome and related conditions. Timely diagnosis and intervention are essential for minimizing the impact of MASLD. This study sought to analyze the efficacy of advanced anthropometric indices and non-invasive steatosis markers in diagnosing MASLD. Methods: This cross-sectional retrospective study evaluated the data from 578 Turkish patients admitted to our gastroenterology clinic. MASLD was diagnosed based on internationally recognized criteria. The evaluated parameters included body mass index (BMI); waist–hip ratio (WHR); waist–height ratio (WHtR); body roundness index (BRI); conicity index (CI); a body shape index (ABSI); visceral adiposity index (VAI); abdominal volume index (AVI); lipid accumulation product (LAP); fatty liver index (FLI); hepatic steatosis index (HSI); and triglyceride–glucose index (TyG) and its variants TyG–waist circumference(WC) and TyG–BMI. Results: Among 215 men, 103 (56.9%) met the criteria for MASLD, while 260 out of 363 women (65.5%) fulfilled the criteria. In the receiver operating characteristic (ROC) analysis for identifying MASLD, TyG–WC (0.826), TyG–BMI (0.820), and FLI (0.830) achieved the highest area under the curve (AUC) values, with statistically significant differences observed in their pairwise comparisons against the other parameters. Conclusions: TyG–WC and TyG–BMI are comparable to FLI in terms of simplicity of calculation and superior diagnostic accuracy, making them valuable non-invasive alternatives for MASLD screening and diagnosis.