Insulin therapy causes mostly weight gain. Long acting insulin analogues are able to induce small weight loss in Type 1 diabetes or only a small weight increase or weight loss in Type 2 diabetic patients. Procedures of bariatric surgery are very important in the treatment being able to induce remission of Type 2 diabetes. Weight reduction can be supported also using the new class of antiadiabetic drugs- SGLT inhibitors which are blocking glucose absorption in kidneys.