1. Department of Nutrition and Dietetics, Nutrition, Food and Health Research Centre, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NN, United Kingdom; DEFRA Central Science Laboratory (CSL), Sand Hutton, York YO41 1LZ, United Kingdom; and TNO-BIBRA International, Woodmansterne Road, Carshalton, Surrey SM5 4DS, United Kingdom