Adverse metabolic consequences of nutritional support: macronutrients.

The administration of a complete and well-balanced diet commensurate with the requirements and limitations of individual patients is essential to obtain maximal benefit of nutritional therapy. Complications related to the provision of nutritional therapy must be considered when providing nutrition support to patients with malignant diseases. Some of these complications are not exclusive of the form of therapy, whereas others are inherent in the different components of nutrient solutions used. A sound knowledge of clinical nutrition as well as the establishment of nutrition support teams will help to reduce the incidence of adverse reactions related to the nutritional treatment. Further research is necessary to understand better the mechanisms of malnutrition in cancer patients and the mechanisms by which several organs and systems are adversely affected during nutrition support. New methods and devices will lead to a more efficacious administration of nutritional requirements.