Funding for this research was provided by:
Norske Kvinners Sanitetsforening (40402)
Text and Data Mining valid from 2018-07-14
Received: 28 March 2018
Accepted: 2 July 2018
First Online: 14 July 2018
Ethics approval and consent to participate
: The protocol for the present study was notified to the Norwegian Social Science Data Services, Data Protection Official for Research, 13/09/2016, reference 49951. Informed consent was obtained from parents of all participating children and from all participating kindergartens and kindergarten staff.
: Not applicable.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.