1. Center for Health Equity Research, Department of Social Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
2. Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, Illinois
3. Department of Global Health, School of Public Health, University of Washington, Seattle, Washington
4. Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
5. Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
6. Center for Health Promotion and Disease Prevention, University of North Carolina at Chapel Hill, 1700 Martin Luther King Jr. Blvd., CB# 7426, Chapel Hill, NC, 27599-7426.