Diabetic patients are recommended to drink more plain water because it does not contain carbohydrates and has little effect on blood sugar. Drinking more plain water has the following benefits: 1. Drinking more plain water can increase the patient’s blood volume and reduce blood viscosity, which can reduce the occurrence of cerebral infarction for elderly diabetic patients. 2. Drinking more plain water can increase the excretion of urine, thus increasing the excretion of glucose and facilitating the control of blood sugar. 3. Drinking more plain water can increase the volume of urine and prevent the occurrence of urinary tract infection, which is especially important for female diabetic patients. This is especially important for women with diabetes, so it is beneficial for diabetics to drink more plain water.