What gastric cancer patients cannot eat should be analyzed according to different degrees of patients’ conditions. I. If the patient with gastric cancer is accompanied by pyloric obstruction. After the patient eats, the food cannot reach the ileum through duodenum and there will be violent vomiting symptoms. In this case, the patient cannot eat any food and can only maintain energy through intravenous rehydration. Second, if a patient with gastric cancer has undergone surgical treatment and is in the post-operative recovery period. The foods that cannot be eaten are as follows: 1. raw and cold foods such as iced watermelon, popsicles, ice-cream, cold water, raw tomatoes, raw cucumbers, etc. 2. greasy foods such as fritters, doughnuts, roast meat, roast duck, roast chicken, pig’s feet, etc. 3. indigestible foods such as corn, pancakes, leeks, glutinous rice and other foods. These foods will increase the burden on the patient’s gastrointestinal tract, causing abdominal pain and bloating, which is not conducive to the recovery of the patient’s condition.