The nutrition of patients in which the cancerous disease has already spread does not cure the disease . This statement is radically contrary to multiple theories supported by some followers of these cancer specific diets (ex. the shark cartilage diet, the distilled water and wheat seeds diet, etc.). This situation is also encountered in the neoplasm of the digestive system .
The objectives of the cancerous diseases nutrition are represented by the ability to provide the caloric and nutritional requirements which are able to improve the patients clinical status, to increase the effort capacity, to extend the survival duration and to amplify the capacity to tolerate chemotherapy and radiation therapy .