Hrolfsdottir, Laufey, Unit for Nutrition Research, Landspitali University Hospital and Faculty of Food Science and Nutrition, University of Iceland, Reykjavik,and Landspitali University Hospital and Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland; Institution of Health Science Research, University of Akureyri and Akureyri Hospital, Akureyri, Iceland, Iceland