Weight loss after gastric cancer surgery is relatively common, which requires patients to have regular treatment, and at the same time to strengthen nutritional supportive therapy to improve body quality. Gastric cancer is a malignant tumor lesion that occurs in the stomach, and most patients need surgical treatment to remove the cancerous tumor to slow down the progress of tumor lesion development, and also to reduce the continuous consumption of the tumor lesion on the patient’s body functions. Affected by the lesion, patients may then experience weight loss and malnutrition. After gastric cancer surgery, due to the loss of tissue organs for food grinding, digestion and absorption, malnutrition and weight loss may also occur. Therefore, weight loss after stomach cancer surgery is a relatively common situation. For this situation, patients should establish a correct concept of the disease. On the one hand, active treatment under the guidance of doctors. Take measures such as radiotherapy, chemotherapy and targeted drug therapy after surgery to try to stabilize the condition and slow down the progress of lesion development. On the other hand, we should have a reasonable diet and eat some high-quality protein food, such as: fish, chicken, lean pork and so on. Pay attention to eating small meals and chewing slowly to enhance food absorption, improve body quality and weight.