1. Tropical Medicine Research Institute (P.M.F.-E., D.S.T., A.T.B., T.E.F., M.S.B.), Jamaica, West Indies;
2. Department of Surgery, Radiology, Anaesthesia, and Intensive Care (A.T.B.), The University of the West Indies, Mona, Kingston 7, Jamaica, West Indies;
3. Medical Research Council Lifecourse Epidemiology Unit (C.O.), Southampton SO16 6YD, United Kingdom;
4. Nutrition and Metabolism Unit (C.D.B.), School of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom;
5. Institute of Developmental Sciences (M.A.H.), Southampton SO16 6YD, United Kingdom;
6. Centre for Human Evolution, Adaptation, and Disease (P.D.G.), Liggins Institute, University of Auckland, Auckland 1142, New Zealand