Gains in muscle mass are difficult to achieve in cancer unless specific metabolic abnormalities are targeted. Recently, the investigators observed that essential amino acid mixtures (EAA) are able to induce protein anabolism in patients with stage III and IV non-small cell lung cancer. Previous experimental research and clinical studies in cachectic conditions (including cancer) indicate that polyunsaturated fatty acids (PUFA) are able to attenuate protein degradation by improving the anabolic response to feeding and by decreasing the acute phase response. Eicosapentaenoic acid (EPA) (in combination with docosahexaenoic acid (DHA)) has been shown to effectively inhibit weight loss in several disease states; however, weight and muscle mass gain was not present or minimal. Recent studies examining the effect of fish oil supplementation in relation to chemotherapy have been inconclusive but found potential beneficial effects on physical performance and increased efficacy of first-line chemotherapy in patients with non-small cell lung cancer.