Literature concerning nutritional interventions in elderly patients with gastrointestinal cancer, with special reference to randomized clinical trials, has been critically reviewed. This segment of oncologic population was found to be penalized by a high prevalence of malnutrition and sarcopenia which translated in an increased rate of toxicity from chemotherapy, poor compliance with oncologic treatments, and, finally, with a poor prognosis. Attempts to reverse this condition included a potentiation of nutrients intake which should sequentially proceed through the use of dietary counseling and administration of standard or ω-3 fatty acid-enriched oral supplements to finally come to enteral or parenteral nutrition. Randomized clinical trials investigating the effects of simple dietary advice and use of standard oral supplements were disappointing as regards long-term compliance and results. Nutritional and clinical benefits were reported with the use of ω-3 fatty acid-enriched oral supplements and especially with long-term supplemental parenteral nutrition. Despite the general recommendation of the scientific community that emphasizes the use of the enteral route, whenever possible, for delivering the nutritional support, it appears from the literature that more consistent benefits can be achieved, especially in the long-term nutritional support, when an insufficient oral nutrition is partnered with intravenous nutrition.