1. Non-Communicable Diseases Research Unit, South African Medical Research Council (SAMRC), Cape Town 7505, South Africa
2. Center of Excellence for Nutrition, North-West University, Potchefstroom 2531, South Africa
3. Department of Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town 7700, South Africa
4. Department of Medicine, University of Yaounde, Yaounde 00237, Cameroon