1 Tampere Centre for Child Health Research and Tampere University Hospital, University of Tampere, Tampere, Finland; Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Frederiksberg DK-1958, Denmark. Electronic address: andre.briend@gmail.com.
2 Centre for Tropical Medicine & Global Health, Old Road Campus, Oxford, UK; KEMRI/Wellcome Trust Research Programme, Kilifi, Kenya.