1. Faculty of Health Promotion, Sports and Leisure Studies School of Education University of Iceland Reykjavik Iceland
2. The Icelandic Gerontological Research Institute National University Hospital of Iceland & Faculty of Medicine University of Iceland Reykjavik Iceland
3. Unit for Nutrition Research National University Hospital of Iceland & Faculty of Food Science and Nutrition, University of Iceland Reykjavik Iceland
4. School of Social Science University of Iceland Reykjavik Iceland
5. Institute of Gerontology and Aging Research Network School of Health and Welfare Jönköping University Jönköping Sweden