1 Department of Health Promotion, Buskerud and Vestfold University College, Tønsberg, Norway steffen.torp@hbv.no.
2 Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
3 Nordic School of Public Health NHV, Gothenburg, Sweden Department of Health and Caring Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.