1. School of Education, University of Iceland, v/Stakkahlid, 105 Reykjavik, Iceland
2. Department of Food and Nutrition, Umeå University, SE-901 87 Umeå, Sweden
3. Unit for Nutrition Research, Faculty of Food Science and Nutrition at the University of Iceland and Landspitali-National University Hospital, Eiriksgata 29, 101 Reykjavik, Iceland.
4. The Discipline of Public Health, University of Turku, Joukahaisenkatu 3-5 A, 20014 Turun yliopisto, Finland
5. University of Eastern Finland, Kuopio campus, Institute of Public Health and Clinical Nutrition, P.O. Box 1627, FI-70211 Kuopio, Finland