To investigate the associations of household and neighbourhood socio-economic position (SEP) with indicators of both under- and overnutrition in adolescents and to explore sex differences.

Analysis of anthropometric, household and neighbourhood SEP data from the Birth to Twenty Plus cohort born in 1990. Anthropometric outcomes were BMI (thinness, overweight and obesity) and percentage body fat (%BF; low, high). Associations between these and the household wealth index, caregiver education and neighbourhood SEP tertile measures were examined using binary logistic regression.

Johannesburg–Soweto, South Africa.

Adolescents aged 17–19 years (n 2019; 48·2 % men).

Women had a significantly higher combined prevalence of overweight/obesity (26·2 %) than men (8·2 %) whereas men had a significantly higher prevalence of thinness than women (22·2 % v. 10·6 %, respectively). Having a low neighbourhood social support index was associated with higher odds of high %BF in women (OR=1·59; 95 % CI 1·03, 2·44). A low household wealth index was associated with lower odds of both overweight (OR=0·31; 95 % CI 0·12, 0·76) and high %BF in men (OR=0·28; 95 % CI 0·10, 0·78). A low or middle household wealth index was associated with higher odds of being thin in men (OR=1·90; 95 % CI 1·09, 3·31 and OR=1·80; 95 % CI 1·03, 3·15, respectively). For women, a low household wealth index was associated with lower odds of being thin (OR=0·49; 95 % CI 0·25, 0·96).

The study highlights that even within a relatively small urban area the nutrition transition manifests itself differently in men and women and across SEP indicators. Understanding the challenges for different sexes at different ages is vital in helping to plan public health services.

The present paper examines dietary intake and body composition in antiretroviral (ARV)-naïve HIV-positive compared with HIV-negative South African women, as well as the impact of disease severity on these variables.

Baseline data from a longitudinal study assessing bone health in HIV-negative and HIV-positive premenopausal South African women over 18 years of age were used. Anthropometry and body composition, measured by dual energy X-ray absorptiometry, were analysed together with dietary intake data assessed using an interviewer-based quantitative FFQ.

Soweto, Johannesburg, South Africa.

Black, urban South African women were divided into three groups: (i) HIV-negative (HIV−; n 98); (ii) HIV-positive with preserved CD4 counts (HIV+ non-ARV; n 74); and (iii) HIV-positive with low CD4 counts and due to start ARV treatment (HIV+ pre-ARV; n 75).

The prevalence of overweight and obesity was high in this population (59 %). The HIV+ pre-ARV group was lighter and had a lower BMI than the other two groups (all P < 0·001). HIV+ pre-ARV women also had lower fat and lean masses and percentage body fat than their HIV− and HIV+ non-ARV counterparts. After adjustment, there were no differences in macronutrient intakes across study groups; however, fat and sugar intakes were high and consumption of predominantly refined food items was common overall.

HIV-associated immunosuppression may be a key determinant of body composition in HIV-positive women. However, in populations with high obesity prevalence, these differences become evident only at advanced stages of infection.

The present study aimed to assess the relationship between dietary habits, change in socio-economic status and BMI Z-score and fat mass in a cohort of South African adolescents.

In the longitudinal study, data were collected at ages 13, 15 and 17 years on a birth cohort who have been followed since 1990. Black participants with complete dietary habits data (breakfast consumption during the week and at weekends, snacking while watching television, eating main meal with family, lunchbox use, number of tuck shop purchases, fast-food consumption, confectionery consumption and sweetened beverage consumption) at all three ages and body composition data at age 17 years were included in the analyses. Generalized estimating equations were used to test the associations between individual longitudinal dietary habits and obesity (denoted by BMI Z-score and fat mass) with adjustments for change in socio-economic status between birth and age 12 years.

Birth to Twenty (Bt20) study, Soweto-Johannesburg, South Africa.

Adolescents (n 1298; 49·7 % male).

In males, the multivariable analyses showed that soft drink consumption was positively associated with both BMI Z-score and fat mass (P < 0·05). Furthermore, these relationships remained the same after adjustment for socio-economic indicators (P < 0·05). No associations were found in females.

Longitudinal soft drink consumption was associated with increased BMI Z-score and fat mass in males only. Fridge ownership at birth (a proxy for greater household disposable income in this cohort) was shown to be associated with both BMI Z-score and fat mass.