Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, 171 65 Solna, Sweden. Division of Psychological and Social Medicine and Developmental Neurosciences, Faculty of Medicine, Technische Universität Dresden, 1099 Dresden, Germany. Research Unit Eating Disorders, Psychiatric Center Ballerup, Maglevænget 32, 2750 Ballerup, Denmark. Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. School of Psychology, Curtin University, Perth U1987, Australia. Division of Paediatrics, University of Western Australia, Perth 6907, Australia. Department of Biomedical Sciences, University of Copenhagen, 1353 Copenhagen, Denmark. Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Department of Clinical Medicine, University of Copenhagen, 2200 N Copenhagen, Denmark.