El cáncer afecta seriamente el estado nutricional del paciente. La pérdida de peso, y principalmente de masa libre de grasa, puede ser de gran magnitud, como sucede cuando afecta órganos sólidos. Asimismo, se producen anormalidades metabólicas que impiden la adecuada utilización de los nutrientes, por lo cual es necesario ajustar, en forma individual, el plan de alimentación. Los efectos secundarios generados por los medicamentos anticancerosos dificultan aún más una alimentación adecuada. Un pobre estado nutricional limita el tratamiento, sea de quimioterapia o de radioterapia, pues aumenta la intolerancia, lo cual impide la administración de las dosis usuales o su aumento en magnitud o frecuencia. También el estado de desnutrición significa un mayor reconocido riesgo cuando se emprende un tratamiento quirúrgico. La implementación del tratamiento médico nutricional (evaluación, diagnóstico, intervención, vigilancia y seguimiento) es fundamental para el manejo multimodal que requieren estos pacientes. La selección del tipo de soporte nutricional debe ser personalizada y su principal objetivo también debe estar encaminado a mejorar la calidad de vida. En muchos casos la fortificación de los alimentos, especialmente con proteína de alto valor biológico, logra mejorar el estado nutricional. Cuando esta no es suficiente, o sea aquella que cubre menos del 60% del requisito proteico-calórico diario, se deben considerar alternativas, como la nutrición entérica por sonda o la parenteral suplementaria. Cuando el pronóstico de supervivencia es mayor de tres meses o cuando la localización del tumor o las alteraciones gastrointestinales impiden el empleo de la vía entérica, se sugiere la nutrición parenteral total, la cual, idealmente, debería ser ambulatoria. Hoy en día se considera que la nutrición y el ejercicio son factores fundamentales en el manejo de estos pacientes, y que no hay bases para considerar que alimentar al individuo es alimentar el tumor.

Cancer has profound effects on the nutritional status of patients. Depending on the location of the neoplasm, weight loss -mainly of fat-free mass- can be of great magnitude. This is the case when tumors are present in solid organs. In this type of cancer, there are metabolic abnormalities that prevent the proper utilization of nutrients, making it necessary to adjust the feeding plan. Furthermore, the side effects generated by anticancer drugs make it even more difficult to eat properly. Poor nutritional status limits the treatment of both chemo and radiotherapy as it increases the intolerance to appropriate feeding. Malnutrition makes the administration of adequate doses difficult, as well as increases their concentration or frequency. Malnutrition increases the risk of surgical treatment. The implementation of nutritional medical therapy (evaluation, diagnosis, intervention, monitoring and follow-up) is fundamental for the multimodal management required by these patients. The selection of the type of nutritional support should be personalized and its main objective should be aimed at improving the quality of life. Food fortification, especially with protein of high biological value, improves the adequacy of the nutritional management. When this is not enough (meaning when it covers less than 60% of the daily caloric protein requirement), alternative routes such as enteral feeding by tube or supplementary parenteral nutrition should be considered. In some cases, with prognosis greater than three months of survival and in whom the location of the tumor or the presence of gastrointestinal disorders prevent the use of the enteral route, total parenteral nutrition is suggested, which ideally should be ambulatory. Currently it is considered that both nutrition and exercise constitute a fundamental and integral part in the management of oncology patients and that there is no solid base to think that “feeding the patient is feeding the tumor”.Cancer has profound effects on the nutritional status of patients. Depending on the location of the neoplasm, weight loss -mainly of fat-free mass- can be of great magnitude. This is the case when tumors are present in solid organs. In this type of cancer, there are metabolic abnormalities that prevent the proper utilization of nutrients, making it necessary to adjust the feeding plan. Furthermore, the side effects generated by anticancer drugs make it even more difficult to eat properly. Poor nutritional status limits the treatment of both chemo and radiotherapy as it increases the intolerance to appropriate feeding. Malnutrition makes the administration of adequate doses difficult, as well as increases their concentration or frequency. Malnutrition increases the risk of surgical treatment. The implementation of nutritional medical therapy (evaluation, diagnosis, intervention, monitoring and follow-up) is fundamental for the multimodal management required by these patients. The selection of the type of nutritional support should be personalized and its main objective should be aimed at improving the quality of life. Food fortification, especially with protein of high biological value, improves the adequacy of the nutritional management. When this is not enough (meaning when it covers less than 60% of the daily caloric protein requirement), alternative routes such as enteral feeding by tube or supplementary parenteral nutrition should be considered. In some cases, with prognosis greater than three months of survival and in whom the location of the tumor or the presence of gastrointestinal disorders prevent the use of the enteral route, total parenteral nutrition is suggested, which ideally should be ambulatory. Currently it is considered that both nutrition and exercise constitute a fundamental and integral part in the management of oncology patients and that there is no solid base to think that “feeding the patient is feeding the tumor”.