1. Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
2. INCAP Research Center for the Prevention of Chronic Diseases, Institute of Nutrition of Central America and Panama, Guatemala City, Guatemala
3. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
4. Center for Human Growth and Development, University of Michigan, Ann Arbor, MI, USA