Unit of Nutrition and Cancer, Cancer Epidemiology Research Program, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain. Unit Breast Cancer Screening Unit, Cancer Prevention and Control Program, Catalan Institute of Oncology-IDIBELL, L'Hospitalet de Llobregat, Barcelona, Spain. Clinical Nutrition Unit, Catalan Institute of Oncology (ICO-IDIBELL), Barcelona, Spain. Department of Medical Oncology-ICO, Hospital Universitari de Girona Dr Josep Trueta, Girona, Spain. Breast Cancer Unit, Catalan Institute of Oncology (ICO-IDIBELL), Barcelona, Spain. Department of Breast Cancer Oncology, Hospital Universitari Vall d'Hebron, Barcelona, Spain. Department of Medical Oncology-ICO, Hospital Germans Trias i Pujol, Badalona, Spain. Translational Genomics and Targeted Therapeutics, Institut d'Investigacions Biomèdiques Pi i Sunyer IDIBAPS, Barcelona, Spain. Department of Medical Oncology, Hospital del Mar, Barcelona, Spain. Department of Medical Oncology, Consorci Sanitari de Terrassa, Terrassa, Spain. Department of Physiological Sciences II, School of Medicine, University of Barcelona, Barcelona, Spain. Centre for Health Protection, National Institute for Public Health and the Environment, Bilthoven, The Netherlands. Nutrition and Metabolism Department, International Agency for Research on Cancer, Lyon, France.