1. Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
2. UNC Project-Malawi, Lilongwe, Malawi
3. Department of Health Behavior, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
4. Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
5. RTI International, Research Triangle Park, NC, USA