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.

Parenteral nutrition-associated liver disease (PNALD) is frequently observed in patients who require long-term parenteral nutrition. PNALD is diagnosed by clinical presentation, biochemical liver function test, long-term usage of parenteral nutrition, and negative workup for other liver diseases. Pathogenesis of PNALD is multifactorial and includes prematurity, nutritional excess, sepsis, and lack of enteral nutrition. Since PNALD was first reported more than 30 years ago, there have been various attempts to find effective treatments for PNALD. Cyclic parenteral nutrition and use of ω-3 polyunsaturated long-chain fatty acids (ω-3 PUFA) instead of ω-6 PUFA were reported worldwide as effective treatments. This article reviews the literature relating to PNALD.