Liver disease and nutritional status are known to affect each other. When liver disease is severe, patients become more malnourished and have a worse prognosis. Adequate nutritional support for patients with liver diseases can improve a patient’s condition and prognosis. In acute liver failure, malnutrition is uncommon, and the disease prognosis is determined within a short time. Patients with acute liver failure may survive and recover if they receive a transplant. Considerations should be given to the management of glucose intolerance and hyperammonemia. However, well-designed clinical trials are still lacking until now. In the case of liver cirrhosis, malnutrition may occur due to a variety of causes, and as in other diseases, oral or enteral nutrition is preferred to parenteral nutrition. Even if esophageal varices are present, it is possible to install a feeding tube. However, in the presence of ascites, PEG (percutaneous endoscopic gastrostomy) becomes contraindicated due to risk of complications. Calorie intake of 30~35 Kcal/kg/day and protein intake of 1.2 to 1.5 g/kg/day are appropriate. Protein restriction should not be necessary unless hepatic encephalopathy is severe. Late evening snacking and intake of branched chain amino acids can be helpful.

Nutrition therapy is a critical component of treatment for patients with acute respiratory distress syndrome/acute lung injury. Underfeeding can cause cumulative caloric deficits, loss of lean body mass, and deteriorationof respiratory muscle strength, which can all lead to poor outcomes. However, overfeeding, on the other hand, is also harmful due to hypercapnia and hyperglycemia, which can increase the risk of infection. Therefore, an optimal nutrition therapy is very important. Although the importance of nutrition in this patient population is widely accepted, trophic enteral feeding during the acute phase is suggested in immunologic aspect to prevent nutrition-related complications. High-fat and low-carbohydrate enteral nutrition can decrease CO₂ production and help shorten the duration of mechanical ventilation in patients with acute respiratory distress syndrome. There are still areas of controversy regarding the role of omega-3 fatty acids and antioxidants, which are known to prevent oxidative cellular injury, modify the metabolic response, and modulate immunity and inflammation.