The diagnostic criteria for Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) and Metabolic Associated Steatotic Liver Disease (MASLD) aim to refine the classification of fatty liver diseases previously grouped under Non-Alcoholic Fatty Liver Disease (NAFLD). This study evaluates the applicability of the MAFLD and MASLD frameworks in NAFLD patients, exploring their clinical utility in identifying high-risk patients. A total of 369 NAFLD patients were assessed using MAFLD and MASLD diagnostic criteria. Baseline characteristics, metabolic profiles, hepatic fibrosis, and cardiovascular risks were compared across the groups. Among NAFLD patients, 97.55% (n = 359) met MASLD criteria, and 97.01% (n = 357) fulfilled MAFLD criteria. Both frameworks MAFLD and MASLD captured overlapping populations, with MASLD encompassing slightly more cases. No significant differences were observed in metabolic risk factors, fibrosis indices (APRI, FIB-4, NAFLD fibrosis score), or cardiovascular risk (10-year ASCVD score). A small subset of lean NAFLD patients (10 cases) with distinct profiles remained uncategorized by either framework. Pure NAFLD cases (n = 10) were with mild insulin resistance (HOMA-IR: 3.07 ± 0.33) and slightly elevated LDL (102.5 ± 42.87 mg/dL), while fibrosis indices indicated low fibrosis risk. Steatosis indices supported the diagnosis of early-stage NAFLD with preserved liver function. These patients do not meet the criteria for inclusion in the MAFLD or MASLD frameworks, highlighting a gap in the current diagnostic systems. MAFLD and MASLD criteria align closely with NAFLD in capturing patients with metabolic risk with MASLD-enhanced inclusivity. Further refinement is required to address heterogeneity, particularly in lean NAFLD patients. Hypertension prevalence was comparable (17.4% in NAFLD, 18.2% in MAFLD, 17.8% in MASLD; p = 0.960), as was diabetes mellitus (36.7%, 37.8%, and 37.6%, respectively; p = 0.945). Body mass index was also similar across groups, with medians of 33.25, 33.6, and 33.4 kg/m (p = 0.731). Non-invasive markers of hepatic fibrosis, including APRI, FIB-4, and NAFLD fibrosis scores, did not differ significantly, with median FIB-4 scores around 1.05 (p = 0.953). Similarly, were the results of hepatic steatosis index and ASCVD score.