[1] Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Dept Int Hlth, Baltimore, MD 21205 USA
[2] Boston Univ, Boston, MA 02215 USA
[3] Univ N Carolina, Inst Nutr Res, Chapel Hill, NC USA
[4] NIH, Bethesda, MD 20892 USA
[5] Univ Massachusetts, Amherst, MA 01003 USA