1. Regional Centre for Health Care Development, St. Olavs Hospital, Trondheim, Norway
2. Department of Public Health and Nursing, NTNU, Trondheim, Norway
3. Regional Center for Obesity Research and Innovation, Department of Surgery, St. Olavs Hospital, Trondheim, Norway
4. Department of Clinical Molecular Medicine, NTNU, Trondheim, Norway
5. Mannheim Institute of Public Health, Social and Preventive Medicine, Mannheim Medical Faculty of the Heidelberg University, Mannheim, Germany
6. Department of Health Sciences, University of York, UK