Background/aims <p>The predictive value of bioelectrical impedance analysis (BIA) parameters and liver enzymes for metabolic dysfunction-associated steatotic liver disease (MASLD) in young adults is unclear. We aimed to investigate the usefulness of BIA parameters and liver enzymes in MASLD screening in young adults.</p> Methods <p>Overall, 2,647 participants aged 19–30&#xa0;years were evaluated by sex. Logistic regression analyses were performed with MASLD as the dependent variable. Receiver operating characteristic (ROC) curves were used to compare the predictive ability for MASLD.</p> Results <p>In males, percentage body fat (PBF), total body fat (TBF), visceral fat area (VFA), abdominal subcutaneous fat (ASF), alanine aminotransferase (ALT), and elevated ALT levels were positively associated with MASLD, whereas skeletal muscle index (SMI) and AST/ALT were negatively associated after adjusting for age, body mass index, and moderate physical activity. In females, PBF, TBF, ASF, AST, ALT, low SMI (LSMI), and elevated ALT levels were positively associated with MASLD, whereas SMI and AST/ALT were negatively associated. The areas under the ROC curves (AUCs) of PBF, TBF, VFA, ASF, SMI, AST, ALT, and AST/ALT were 0.818, 0.837, 0.834, 0.837, 0.818, 0.653, 0.759, and 0.790 respectively, in males. In females, the corresponding values were 0.915, 0.939, 0.934, 0.940, 0.915, 0.620, 0.799, and 0.849 respectively. The AUC of LSMI was significantly higher than that of increased ALT levels in females.</p> Conclusions <p>BIA parameters and ALT levels are useful for predicting MASLD in young adults. BIA parameters have superior predictive ability than liver enzymes.</p>