[1] Univ North Carolina Chapel Hill, Carolina Populat Ctr, Chapel Hill, NC 27516 USA
[2] Univ North Carolina Chapel Hill, Gillings Sch Global Publ Hlth, Dept Nutr, Chapel Hill, NC 27516 USA
[3] Univ Edinburgh, Global Acad Agr & Food Syst, Midlothian, Scotland
[4] Stanford Univ, Sch Med, Dept Pediat, 3145 Porter Dr A103, Palo Alto, CA 94304 USA
[5] Stanford Univ, Sch Med, Dept Hlth Policy, Stanford, CA 94305 USA