Using machine learning algorithms to investigate primary malnutrition factors in critically ill patients, our study identified significant biomarkers, including BMI; age; energy intake; neutrophil and platelet counts; magnesium and sodium ions; total bilirubin; PO2; and serum creatinine, IL-6, hs-CRP, total protein, fasting glucose, hemoglobin, and albumin levels. Here, ALB is linked to malnutrition.