Diet therapy is the basic treatment of diabetes. Diabetic patients should have a balanced diet and a variety of foods to ensure blood sugar stability and nutrition for diabetic patients. Diabetic patients should choose a diet with low sugar content, such as oats, black rice, buckwheat, soybeans, etc. As for corn, diabetic patients can eat it, because corn contains less sugar and calories than rice, and it contains crude and soluble fiber, protein, fat, mineral elements and vitamins, especially crude fiber, which is good for diabetic patients to lower their postprandial blood sugar level, but it is better for diabetic patients not to eat more than 50g of corn each time.