1. Division of Nutrition and Metabolic Diseases, Center for Human Nutrition, UT Southwestern Medical Center, Dallas, Texas 75390
2. McDermott Center for Human Growth and Development, UT Southwestern Medical Center, Dallas, Texas 75390
3. Division of Endocrinology and Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas 75390
4. Quest Diagnostics Nichols Institute, San Juan Capistrano, California 92665