Malnutrition, characterized by protein and energy deficiency, is considered the most prevalent complication of liver disease. The pathofysiology includes reduced food intake, maldigestion and malabsorption but also avoidable iatrogenic factors, such as prescribed fasting, frequent paracenteses and "liver-diets" poor in fat and protein. Liver insufficiency corresponds to a state of accelerated starvation. The diminished glucose tolerance and low glycogen stores in cirrhotic patients result in a reduced availability of glucose as energy source. The prevalence of undernutrition depends upon the severity of the liver insufficiency and the method of nutritional assessment. The aim of the nutritional plan is to realize a sufficient oral diet which includes enough proteins and calories. Several extra calorie supplements are indicated to surmount the lack of available glucose. The evidence in support of branched chain amino acid supplements is limited. Salt intake should be moderately restricted in case of ascites. Nasogastric tube feeding is indicated when patients are unable to maintain an adequate oral intake. In case tube feeding is not possible, total parenteral nutrition may be necessary to maintain an anabolic state.