OBJECTIVE: To review data on selected risk factors related to the emergence of noncommunicable diseases (NCDs) in the black population of South Africa. METHODS: Data from existing literature on South African blacks were reviewed with an emphasis placed on changes in diet and the emergence of obesity and related NCDs. DESIGN: Review and analysis of secondary data over time relating to diet, physical activity and obesity and relevant to nutrition-related NCDs. SETTINGS: Urban, peri-urban and rural areas of South Africa. National prevalence data are also included. SUBJECTS: Black adults over the age of 15 years were examined. RESULTS: Shifts in dietary intake, to a less prudent pattern, are occurring with apparent increasing momentum, particularly among blacks, who constitute three-quarters of the population. Data have shown that among urban blacks, fat intakes have increased from 16.4% to 26.2% of total energy (a relative increase of 59.7%), while carbohydrate intakes have decreased from 69.3% to 61.7% of total energy (a relative decrease of 10.9%) in the past 50 years. Shifts towards the Western diet are apparent among rural African dwellers as well. The South African Demographic and Health Survey conducted in 1998 revealed that 31.8% of African women (over the age of 15 years) were obese (body mass index (BMI) > or = 30kg m(-2)) and that a further 26.7% were overweight (BMI > or = 25 to <30 kg m(-2)). The obesity prevalence among men of the same age was 6.0%, with 19.4% being overweight. The national prevalence of hypertension in blacks was 24.4%, using the cut-off point of 140/90 mmHg. There are limited data on the population's physical activity patterns. However, the effects of the HIV/AIDS epidemic will become increasingly important. CONCLUSIONS: The increasing emergence of NCDs in black South Africans, compounded by the HIV/AIDS pandemic, presents a complex picture for health workers and policy makers. Increasing emphasis needs to be placed on healthy lifestyles
