Abstract:The rising prevalence of obesity and excessive adiposity are global public health concerns. Understanding determinants of changes in adiposity over time is critical for informing effective evidence-based prevention or treatment. However, limited information is available to achieve this objective. Cultural, demographic, environmental, and behavioral factors including socio-economic status (SES) likely account for obesity development. To this end, we related these variables to anthropometric measures in 1058 black adult Tswana-speaking South Africans who were HIV negative in a prospective study over five years. Body mass index (BMI) and waist circumference increased in both sexes, whereas triceps skinfold thickness remained the same. Over the five years, women moved to higher BMI categories and more were diagnosed with central obesity. Age correlated negatively, whereas SES, physical activity, energy, and fat intake correlated positively with adiposity markers in women. In men, SES, marital status, physical activity, and being urban predicted increases in adiposity. For women, SES and urbanicity increased, whereas menopause and smoking decreased adiposity. Among men, smokers had less change in BMI than those that never smoked over five years. Our findings suggest that interventions, focusing on the urban living, the married and those with the highest SES-the high-risk groups identified herein-are of primary importance to contain morbidity and premature mortality due to obesity in black South Africans.

Fortification of two staple foods, maize meal and wheat flour (bread), is mandatory, and commercial infant products are widely available in South Africa. Using a 24-hr recall, we determined the contribution of these foods towards nutrient intakes at ages 6 (n = 715), 12 (n = 446), and 18 (n = 213) months in a cohort of children in a peri-urban community, North West province. On the day of recall, commercial infant products were consumed by 83% of children at 6 months, 46% at 12 months, and 15% at 18 months; fortified staples were consumed by 23%, 81%, and 96%, respectively. For consumers thereof, commercial infant products contributed 33% energy and 94% iron intakes at 6 months and 27% energy and 56% iron intakes at 12 months; nutrient densities of the complementary diet was higher than for nonconsumers for most micronutrients. For consumers of fortified staples, energy contribution thereof was 11% at 6 months versus 29% at 18 months; at 18 months, fortified staples contributed >30% of iron, zinc, vitamin A, thiamine, niacin, vitamin B6, and folate; at 12 months, nutrient densities of the complementary diet were higher for zinc, folate, and vitamin B6 but lower for calcium, iron, vitamin A, niacin, and vitamin C than nonconsumers. At ages 12 and 18 months, ~75% of children had low calcium intakes. At 12 months, 51.4% of consumers versus 25.0% (P = 0.005) of nonconsumers of fortified staples had adequate intakes (>EAR) for all eight fortificant nutrients. However, despite fortification, nutrient gaps remain.

Lean mass and fat mass were positively associated with femoral neck, spine and hip BMDs and negatively associated with fracture risk in urban black South African women. Our finding suggests that increasing lean mass rather than fat mass is beneficial to bone health. Our study emphasises the importance of positive lifestyle changes, intake of calcium from dairy and adequate weight to maintain and improve bone health of postmenopausal women.

The new SA cut-point had similar or greater odds of predicting reduced functional ability in older SA women when compared with other internationally accepted cut-points.

Sarcopenia was prevalent among these SA women and was associated with low physical activity energy expenditure.