This is a prospective randomized controlled trial. 180 patients with critical illness will be included and randomly divided into two groups. In the control group, patients will be fed with basic energy; and in the experiment group, the patients will be given extra protein intake except the basic energy intake. The intervention duration will last 6 days. The primary outcomes of this study are urea nitrogen of 24h and prealbumin(PA). And other outcomes include nutritional status, safety indicators and clinical indicators.

Critical illness patients are commonly in the risk of malnutrition, because of various factors. And nutritional supplement, particularly the supplement of protein, can decrease the nitrogen balance, improve the nutritional status, accelerate the speed of healing and decrease the mortality rate. This is a multi center prospective randomized controlled trial. 180 patients with critical illness will be included and randomly divided into two groups. In the control group, patients will be fed with basic energy; and in the experiment group, the patients will be given extra protein intake except the basic energy intake. The intervention duration will last 6 days. The primary outcomes of this study are urea nitrogen of 24h and prealbumin(PA). And other outcomes include nutritional status(total protein, albumin, grip and calf circumference), safety indicators(liver function, kidney function, tolerance, etc.) and clinical indicators(overall complication rate, length of hospital stay and cost).

Inclusion Criteria:

1. diagnosed as critical illness, stayed in ICU;
2. score of M-nutric ≥ 5;
3. score of 3. APACHE Ⅱ >12;
4. anticipation of length of hospital stay > 6 days;
5. 18 ≤ age ≤ 45;
6. pattens volunteer to attend this study and sigh the inform consent form;

Exclusion Criteria:

1. liver function(AST/ALT) of blood test ≥ 2.5 ULN(upper limit of normal); renal function of blood test > 1.6 ULN;
2. the patients are used or are planned to use the Human Albumin solution within 3 days before receiving enteral nutrition;
3. consume any natural food or something made by natural food;
4. patients are used or are planned to use all-in-one solution or amino acid solution within 3 days before receiving enteral nutrition;
5. anticipation of survival time is less than 5 days;
6. have the contraindications of enteral nutrition;
7. patients are allergic to material of the production;
8. patients who are considered not suitable for this study by investigators;

The following data will be shared at the end of the study: demographic data, other baseline data of patients and date of outcomes collected at this research

The data is expected to be available after, December, 2020 and can be used forever

The information should be used for academic research, medical communication, etc., and is prohibited from being used for commercial gain.