1. Department of Psychological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
2. Division of Human Nutrition, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, Netherlands
3. School of Medicine, Washington University in St. Louis, Campus Box 8005, 4523 Clayton Avenue, St. Louis, MO 63110, USA
4. West of Scotland Cancer Surveillance Unit, University of Glasgow, 1 Lilybank Gardens, Glasgow G12 8RZ, UK