[1] Univ Cape Town, Fac Hlth Sci, Dept Human Biol, Div Human Nutr, ZA-7925 Cape Town, South Africa
[2] Univ Cape Town, Fac Hlth Sci, Dept Med, Div Diabet & Endocrinol, ZA-7925 Cape Town, South Africa
[3] Univ Cape Town, Fac Hlth Sci, Dept Med, Chron Dis Initiat Africa, ZA-7925 Cape Town, South Africa
[4] Univ Witwatersrand, Fac Med & Hlth Sci, Dept Paediat, MRC Wits Dev Pathways Hlth Res Unit, ZA-2000 Johannesburg, South Africa
[5] Stellenbosch Univ, Fac Med & Hlth Sci, Div Epidemiol & Biostat, Biostats Unit, ZA-7599 Cape Town, South Africa