1. Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts 02111
2. Division of Nutrition and Physical Activity, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Georgia 30333
3. Division of Environmental Health Laboratory Sciences, Center for Environmental Health, Centers for Disease Control and Prevention, Chamblee, Georgia 30341
4. Division of Health Examination Statistics, National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, Maryland 20782