Gastric cancer is the sixth most common malignancy in the world. However, its mortality has been decreasing in the last years thanks to improvement in diagnostics and therapeutics. Nevertheless, the high rate of malnutrition in patients with gastric cancer still has a major impact on the overall survival and quality of life of patients. The narrative review presents the most recent data on nutritional support in the resectable stages of gastric cancer, with a particular focus on perioperative strategies, and discusses malnutrition in gastric cancer, nutritional support before and after surgery, and the relationship between nutritional support and chemotherapy. Despite the predominantly methodological limitations related to the difficulty of performing randomized controlled trials on nutritional support in cancer patients, this review highlights important points. Nutritional counselling is essential starting from diagnosis. In limited or locally advanced forms (about 40% of cases), the therapeutic cornerstone is represented by gastric surgery. In most of these cases, perioperative chemotherapy is also indicated. Of note, nutritional support varies before and after surgery. In the preoperative period, the goal is to prepare the body for surgery, with available evidence recommending the prescription of immunonutrition (both oral and artificial, as appropriate). In the postoperative period, on the other hand, the objective is to facilitate recovery and adaptation to the new anatomy; an early and combined strategy (oral and enteral) seems to be the most suitable to pursue this. Unfortunately, rigorous data on the relationship between nutritional support and chemotherapy treatments used in resectable gastric cancer are not available. In the absence of strong scientific evidence, it may be useful to adopt a personalized multidisciplinary strategy for each patient wherein the chemotherapy programme is modulated based on nutritional status.