1. Department of Nutrition, Exercise and Sports, University of Copenhagen, 1958 Frederiksberg C, Denmark
2. Department of Paediatrics and Child Health, Makerere University, Kampala P.O. Box 7072, Uganda
3. School of Medicine, Keele University, Keele ST5 5BG, UK
4. The National Institute of Public Health, University of Southern Denmark, 5230 Odense, Denmark
5. Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
6. Tampere Center for Child, Adolescent and Maternal Health Research, Faculty of Medicine and Health Technology, Tampere University, Tampere University Hospital, 33520 Tampere, Finland
7. Department of Infectious Diseases, Rigshospitalet, 2100 Copenhagen, Denmark