1. School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
2. University of Pretoria Diabetes Research Centre (UP DRC), Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
3. Division of Biokinetics, Department of Physiology, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
4. Department of Human Nutrition, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa
5. Department of Internal Medicine, School of Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa