Perioperative nutritional status is closely linked to the development of postsurgical complications, infectious and non-infectious, and mortality. In the Spanish multicenter study Prevalence of Malnutrition and Associated Costs (PREDyCES), the prevalence of malnutrition in surgical patients was established at 10%. 
However, these rates are increased in oncological surgeries in thoracic locations (lung, stomach, esophagus), head and neck, etc.

In this group of patients, the perioperative malnutrition is caused in most cases by decreased intake and metabolic changes (increased basal metabolism, insulin resistance, lipolysis or proteolysis) caused mainly by the systemic inflammatory response syndrome and catabolic factors derived from the oncological disease, all of which effects will be increased in the post-surgical period due to the aggression and metabolic stress that the intervention entails.