Weight loss commonly occurs in lung cancer patients, negatively influencing their quality of life, treatment response and survival. Gains in lean body mass are difficult to achieve in cancer unless specific metabolic abnormalities are targeted. It is our hypothesis that a nutritional supplement containing a high amount of essential amino acids will target the metabolic alterations of cancer patients. Preliminary research performed in our laboratory in elderly supports this hypothesis. We hypothesize that intake of an essential amino acid nutritional supplement will positively influence protein synthesis rate in advanced non-small cell lung cancer (NSCLC) patients. Furthermore, insight in the underlying mechanism of the higher anabolic response of the essential amino acid supplement will be examined. This information will potentially enable us to formulate a supplement that is more effective than normal food intake, and that will reduce the need for muscle protein breakdown.