1. Center for Obesity Northern-Netherlands (CON), Department of Bariatric and Metabolic Surgery, Medical Center Leeuwarden, Leeuwarden, the Netherlands
2. Department of Surgery, Medical Center Leeuwarden, Leeuwarden, The Netherlands
3. Post Graduate School of Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
4. Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands