1. Department of Epidemiology and Biostatistics; Imperial College London; London UK
2. Department of Public Health and General Practice; Faculty of Medicine; Norwegian University of Science and Technology; Trondheim Norway
3. Bjørknes University College; Oslo Norway
4. Department of Epidemiology and Preventive Medicine; Regensburg University Medical Center; Regensburg Germany
5. Department of Endocrinology; Morbid Obesity and Preventive Medicine; Oslo University Hospital; Oslo Norway