The risk factors of Refeeding syndrome were identified energy velocity from day 0 to day 3 ≥ 25% BEE (OR: 6.44, 95% CI: 3.02 to 13.74), intravenous infusion of calcium (OR: 5.79, 95% CI: 1.63 - 20.52), internal GI diseases (OR: 2.38, 95% CI: 1.04 to 5.42).