Lecturer in Public Health Nutrition, Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. Electronic address: C.E.L.Evans@leeds.ac.uk. School of Food Science and Nutrition, King Abdul-Aziz University, PO Box 42807, 21551 Jeddah, Saudi Arabia; Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. Nutritional Epidemiology Group, School of Food Science and Nutrition, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK. Nanjing Municipal Center for Disease Control and Prevention 2, Zizhulin, Nanjing 210003, China.