[1] South African Med Res Council, Noncommunicable Dis Res Unit, Cape Town, South Africa
[2] Univ Cape Town, Cape Town, South Africa
[3] Deakin Univ, Sch Exercise & Nutr Sci, Inst Phys Act & Nutr, Geelong, Vic, Australia
[4] Univ Nottingham, Queens Med Ctr, Sch Life Sci, Med Sch, Nottingham NG7 2UH, England