Inadequate oral food intake and impending or manifest malnutrition are an indication for artificial nutrition. Regarding the course of the disease and quality of life this can improve the prognosis and also prolong the life span. The indication for nutritional therapy should be based on the guidelines for enteral/parenteral nutrition, however, the individual life situation of the patient should also be considered and the patient's volition should be respected. Prerequisites for any nutritional concept are careful evaluation of the nutritional status and specification of the nutritional concept adapted to any disease-specific changes in digestive capacity and metabolism. Enteral nutrition, if possible as volitional nutritional support, should be preferred to parenteral nutrition.