1. Department of Epidemiology and International Health, University of Alabama at Birmingham, Birmingham, AL 35294
2. Medical Research Council, Keneba, The Gambia, West Africa
3. Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011
4. Medical Research Council, Human Nutrition Research, Cambridge, U.K.
5. Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, AL 35294
6. U.S. Department of Agriculture, Western Human Nutrition Research Center and Department of Nutrition, University of California, Davis, CA 95616