1. Non-Communicable Diseases Research Unit, South African Medical Research Council, Tygerberg, Cape Town 7505, South Africa
2. Department of Life and Consumer Sciences, College of Agriculture and Environmental Sciences, University of South Africa, Florida Campus, Johannesburg 1709, South Africa
3. Navrongo Health Research Centre, Ghana Health Service, Navrongo P.O. Box 114, Ghana
4. Faculty of Health Sciences, University of Limpopo, Polokwane 0700, South Africa