1 Department of Public Health Solutions, Finnish Institute for Health and Welfare FI-00271, Helsinki, Finland; Unit of Health Sciences, Faculty of Social Sciences, Tampere University, Tampere, Finland; Tampere University Hospital, Research, Development and Innovation Center, Tampere, Finland; Tampere Center for Child Health Research, Tampere University Hospital, Tampere, Finland. Electronic address: suvi.virtanen@thl.fi.
2 Tampere Center for Child Health Research, Tampere University Hospital, Tampere, Finland; Pediatric Research Center, Children's Hospital, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland; Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Folkhälsan Research Center, Helsinki, Finland.