Body composition of different ethnic groups in South Africa

South Africa is in a state of nutrition transition. As with other societies this is reflected in the emergence of overfatness, sometimes in conjunction with protein malnutrition. These phenomena may be expressed differently in a multi-ethnic society like South Africa with its major ethnic groups (Blacks, Whites, Coloureds and Indians) having varied socio-economic status. National population-based studies of coronary risk factors between 1979 and 1991 have been accessed for anthropometric data as weight and height. Cut-off points for overweight have been applied, to children to age 10 as weight-for-height greater than two Z scores by NCHS reference standards, and to those older than 15 and up to 64 years of age, BMI >= 25 and < 30, and obese >= 30 kg/m2. Data have been stratified by ethnicity, age, gender and place of residence (urban or rural) Urban Black children seem already to have a problem of overweight with a prevalence of 6-18%. For men, urban Whites have the highest prevalence of both overweight (50% in the 45-54 age group) and obesity (20% in the 55-64 age group) in all age groups except the 55-64 age groups for obesity, where Blacks have the higher prevalence (about 29%). Interestingly, the prevalence of overweight in rural women overall (39-52%) exceeds that for urban women (23-31%), although this is not the case for obesity, (prevalence age 25 and beyond, rural 24-39% and urban, 25-60%) where, indeed, in the 45-54 and 55-64 age groups, the urban prevalence exceeds the rural. This raises questions about the factors which reduce or facilitate the transition from overweight to obesity. Urban Black women seem at particular risk of this overweight-to-obesity shift and are known to have a very energy-dense diet. The extent to which overfatness contributes to other coronary risk factors is worth further investigation, given this appears to be less for Blacks than other ethnic groups.