1. Paul-Langerhans-Group for Integrative Physiology, German Diabetes Center (DDZ), Düsseldorf, Germany
2. Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Düsseldorf, Germany
3. Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
4. Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
5. Department of Endocrinology, Morbid Obesity, and Preventive Medicine, Oslo University Hospital and University of Oslo, Oslo, Norway
6. German Center for Diabetes Research (DZD e.V.), Düsseldorf, Germany