Weight loss is an important and effective treatment of morbidly obese women with PCOS. Effective weight reduction will improve manifestations of PCOS and risk factors for developing type 2 diabetes and coronary heart diseases. We compare the effect of two isocaloric low calorie diets (LCD), - one powder-based shake-diet and a fiber rich diet on the above mentioned parameters. In addition we want to compare the weight-maintenance effect the next 44 weeks of two different follow-up programs: A usual care- and a lifestyle-program.