Since the ALT level was more strongly correlated with the risk of NAFLD than the AT index according to the ROC curve analysis, a multivariate analysis was performed with the ALT level and other influential factors, such as the TyG index, HOMA-IR score and male sex, and an NAFLD probability scale was created to help clinicians diagnose NAFLD, with a total of 4 points, with each point increasing the risk of NAFLD by 3.36 times (95% CI: 2.11–5.88). This evidence concerns the gene GPT and metabolic dysfunction-associated steatotic liver disease.