H. Salome Kruger

Physical inactivity is the major determinant of obesity in black women in the North West province, South Africa: the THUSA study

OBJECTIVE We investigated the association between measures and determinants of obesity in African women. METHODS For a cross-sectional study of adult black women in the North West Province, South Africa, we used a stratified sample of 1040 volunteers from 37 randomly selected sites in the province according to the level of urbanization. We analyzed the association between measures of obesity, namely body mass index (BMI), waist circumference, waist-to-hip ratio, triceps and subscapular skinfolds, and socioeconomic factors, dietary intakes, and physical activity. RESULTS The rate of obesity (BMI > 30) in the sample was 28.6%. We found a significant positive association between household income and measures of obesity. After exclusion of underreporters and adjustments for age, smoking, and household income, we found significant positive correlations between total energy intake, fat intake, and BMI. Physical activity index (derived from a subset of 530 subjects) correlated negatively with BMI and waist circumference. Subjects in the highest third of physical activity were less likely to be obese (odds ratio-0.38, 95% confidence interval-0.22-0.66). CONCLUSIONS Women with higher incomes and lower physical activity were at the greatest risk of increased BMI. Physical inactivity showed the strongest association with measures of obesity in this study.

Obesity in South Africa: challenges for government and health professionals

OBJECTIVES To review data on the prevalence, causes and health consequences of obesity in South Africa and propose interventions to prevent and treat obesity and related outcomes. METHODS Data from existing literature were reviewed with an emphasis on changing eating and activity patterns, cultural factors, perceptions and beliefs, urbanisation and globalization. Results of studies on the health consequences of obesity in South Africans are also reviewed. RESULTS Shifts in dietary intakes and activity patterns to higher fat intakes and lower physical activity are contributing to a higher prevalence of obesity. Few overweight black women view themselves as overweight, and some associate thinness with HIV/AIDS. Glucose and lipid toxicity, associated with insulin resistance, play roles in the pathogenesis of the co-morbid diseases of obesity. Elevated free fatty acids in the black population predispose obese black patients to type 2 diabetes. CONCLUSION AND RECOMMENDATIONS Obesity prevention and treatment should be based on education, behaviour change, political support, intersectoral collaboration and community participation, local actions, wide inclusion of the population, adequately resourced programmes, infiltration of existing initiatives, evidence-based planning, and proper monitoring and evaluation. Interventions should have the following components: reasonable weight goals, healthful eating, physical activity and behavioural change. Genes and mutations affecting susceptibility to the development of co-morbidities of obesity and vulnerable periods of life for the development of obesity should be prioritized. Prevention should be managed in community services, identification of high-risk patients in primary healthcare services and treatment of co-morbid diseases in hospital services.

A Micronutrient Powder with Low Doses of Highly Absorbable Iron and Zinc Reduces Iron and Zinc Deficiency and Improves Weight-For-Age Z-Scores in South African Children

Micronutrient powders (MNP) are often added to complementary foods high in inhibitors of iron and zinc absorption. Most MNP therefore include high amounts of iron and zinc, but it is no longer recommended in malarial areas to use untargeted MNP that contain the Reference Nutrient Intake for iron in a single serving. The aim was to test the efficacy of a low-iron and -zinc (each 2.5 mg) MNP containing iron as NaFeEDTA, ascorbic acid (AA), and an exogenous phytase active at gut pH. In a double-blind controlled trial, South African school children with low iron status (n = 200) were randomized to receive either the MNP or the unfortified carrier added just before consumption to a high-phytate maize porridge 5 d/wk for 23 wk; primary outcomes were iron and zinc status and a secondary outcome was somatic growth. Compared with the control, the MNP increased serum ferritin (P < 0.05), body iron stores (P < 0.01) and weight-for-age Z-scores (P < 0.05) and decreased transferrin receptor (P < 0.05). The prevalence of iron deficiency fell by 30.6% (P < 0.01) and the prevalence of zinc deficiency decreased by 11.8% (P < 0.05). Absorption of iron from the MNP was estimated to be 7-8%. Inclusion of an exogenous phytase combined with NaFeEDTA and AA may allow a substantial reduction in the iron dose from existing MNP while still delivering adequate iron and zinc. In addition, the MNP is likely to enhance absorption of the high native iron content of complementary foods based on cereals and/or legumes.

Added sugar intake in South Africa: findings from the Adult Prospective Urban and Rural Epidemiology cohort study

BACKGROUND Obesity and other noncommunicable disease (NCD) risk factors are increasing in low- and middle-income countries. There are few data on the association between increased added sugar intake and NCD risk in these countries. OBJECTIVE We assessed the relation between added sugar intake and NCD risk factors in an African cohort study. Added sugars were defined as all monosaccharides and disaccharides added to foods and beverages during processing, cooking, and at the table. DESIGN We conducted a 5-y follow-up of a cohort of 2010 urban and rural men and women aged 30-70 y of age at recruitment in 2005 from the North West Province in South Africa. RESULTS Added sugar intake, particularly in rural areas, has increased rapidly in the past 5 y. In rural areas, the proportion of adults who consumed sucrose-sweetened beverages approximately doubled (for men, from 25% to 56%; for women, from 33% to 63%) in the past 5 y. After adjustment, subjects who consumed more added sugars (≥10% energy from added sugars) compared with those who consumed less added sugars had a higher waist circumference [mean difference (95% CI): 1.07 cm (0.35, 1.79 cm)] and body mass index (in kg/m²) [0.43 (0.12, 0.74)] and lower HDL cholesterol [-0.08 mmol/L (-0.14, 0.002 mmol/L)]. CONCLUSIONS This cohort showed dramatic increases in added sugars and sucrose-sweetened beverage consumption in both urban and rural areas. Increased consumption was associated with increased NCD risk factors. In addition, the study showed that the nutrition transition has reached a remote rural area in South Africa. Urgent action is needed to address these trends.

Which dietary diversity indicator is best to assess micronutrient adequacy in children 1 to 9 y

OBJECTIVES The aim of this study was to determine the best dietary diversity indicator to measure dietary diversity and micronutrient adequacy in children. METHODS A national representative cross-sectional survey of children ages 1 to 9 y (N = 2,200) was undertaken in all ethnic groups in South Africa. A 24-h recall was done with the mother or caregiver of each child. A dietary diversity score (DDS), the number of food groups consumed at least once in a period of 24 h, was calculated for each child in accordance with 6-, 9-, 13-, and 21-food group (G) indicators and compared with a mean adequacy ratio (MAR). The nutrient adequacy ratio (NAR) was calculated for 11 micronutrients by comparing the distributions of estimated intakes with the Estimated Average Requirements for that micronutrient. The MAR was the average of all NARs. Correlations were done between MAR and DDS and sensitivity and specificity calculated for each group indicator. RESULTS Pearsons correlations between food group indicators and MAR indicate that r values were all highly significant (P < 0.0001). There were no consistent or large differences found between the different group indicators although G13 and G21 appeared to be marginally better. Sensitivity and specificity values in the current study lay between DDS of 3 and 5, suggesting one of these as the best indication of (low) micronutrient adequacy. CONCLUSIONS Overall results seem to indicate that any of the four G indicators can be used in dietary assessment studies on children, with G13 and G21 being marginally better. A cut-off DDS of 4 and 5, respectively, appear best.

What is the nutritional status of children of obese mothers in South Africa

OBJECTIVE To evaluate the anthropometric status of children of obese (body mass index [BMI] ≥30 kg/m2) mothers who participated during the 2005 National Food Consumption Study. METHODS The survey population consisted of children 1-9 y of age and their mothers 16 to 35 y of age living in the same households (n = 1532). A national sample of households was drawn, representative of all nine provinces and urban and rural areas. Trained fieldworkers measured the heights and weights of participants at their homes. RESULTS The prevalence of obesity was high in the mothers (27.9%), particularly in the 26- to 35-y-old (older) group (32.3%) and in urban areas (29.1%). Children of older mothers had a significantly (P < 0.05) higher mean height-for-age Z-score (-0.91) than those of younger mothers (16 to 25 y old, -1.06). Mean weight-for-age and weight-for-height Z-scores were significantly higher in children of obese women compared with those of non-obese women (BMI <30 kg/m2, P < 0.001). Furthermore, obese mothers had significantly more overweight children than non-obese mothers (P < 0.0001). Eighty-four percent of overweight children also had mothers with a BMI ≥25 kg/m2 and 52% had mothers with a BMI ≥30 kg/m2(∗ indicates statistical significance of confidence interval). Stunted mothers had a 1.5 times higher risk of being overweight (BMI ≥25 kg/m2, odds ratio 1.45, confidence interval 1.06-2.01). CONCLUSION Overall, children of obese mothers had significantly higher mean Z-scores than those of mothers who were non-obese. Overweight and obese women were significantly less likely to have stunted or underweight children, whereas underweight women and stunted women were significantly more likely to have underweight and stunted children, respectively.

Vitamin A and anthropometric status of South African preschool children from four areas with known distinct eating patterns

OBJECTIVE The aim of this study was to assess the vitamin A and anthropometric status of South African preschool children from four areas with known distinct eating patterns. METHODS Serum retinol, anthropometric indicators, and dietary intake were determined for randomly selected preschool children from two rural areas, i.e. KwaZulu-Natal (n = 140) and Limpopo (n = 206); an urban area in the Northern Cape (n = 194); and an urban metropolitan area in the Western Cape (n = 207). RESULTS Serum retinol <20 μg/dL was prevalent in 8.2% to 13.6% children. Between 3% (urban-Northern Cape) and 44.2% (rural-Limpopo) children had received a high-dose vitamin A supplement during the preceding 6 mo. Vitamin A derived from fortified bread and/or maize meal ranged from 65 μg retinol activity equivalents (24%-31% of the Estimated Average Requirement) to 160 μg retinol activity equivalents (58%-76% Estimated Average Requirement). Fortified bread and/or maize meal contributed 57% to 59% of total vitamin A intake in rural children, and 28% to 38% in urban children. Across the four areas, stunting in children ranged from 13.9% to 40.9%; and overweight from 1.2% to 15.1%. CONCLUSION Prevalence of vitamin A deficiency was lower than national figures, and did not differ across areas despite differences in socioeconomics, dietary intake, and vitamin A supplementation coverage. Rural children benefited more from the national food fortification program in terms of vitamin A intake. Large variations in anthropometric status highlight the importance of targeting specific nutrition interventions, taking into account the double burden of overnutrition and undernutrition.

Added Sugar, Macro- and Micronutrient Intakes and Anthropometry of Children in a Developing World Context

Objective The objective of this study was to determine the relationship between added sugar and dietary diversity, micronutrient intakes and anthropometric status in a nationally representative study of children, 1–8.9 years of age in South Africa. Methods Secondary analysis of a national survey of children (weighted n = 2,200; non weighted n = 2818) was undertaken. Validated 24-hour recalls of children were collected from mothers/caregivers and stratified into quartiles of percentage energy from added sugar (% EAS). A dietary diversity score (DDS) using 9 food groups, a food variety score (FVS) of individual food items, and a mean adequacy ratio (MAR) based on 11 micronutrients were calculated. The prevalence of stunting and overweight/obesity was also determined. Results Added sugar intake varied from 7.5–10.3% of energy intake for rural and urban areas, respectively. Mean added sugar intake ranged from 1.0% of energy intake in Quartile 1 (1–3 years) (Q1) to 19.3% in Q4 (4–8 years). Main sources of added sugar were white sugar (60.1%), cool drinks (squash type) (10.4%) and carbonated cool drinks (6.0%). Added sugar intake, correlated positively with most micronutrient intakes, DDS, FVS, and MAR. Significant negative partial correlations, adjusted for energy intake, were found between added sugar intake and intakes of protein, fibre, thiamin, pantothenic acid, biotin, vitamin E, calcium (1–3 years), phosphorus, iron (4–8 years), magnesium and zinc. The prevalence of overweight/obesity was higher in children aged 4–8 years in Q4 of %EAS than in other quartiles [mean (95%CI) % prevalence overweight 23.0 (16.2–29.8)% in Q4 compared to 13.0 (8.7–17.3)% in Q1, p = 0.0063]. Conclusion Although DDS, FVS, MAR and micronutrient intakes were positively correlated with added sugar intakes, overall negative associations between micronutrients and added sugar intakes, adjusted for dietary energy, indicate micronutrient dilution. Overweight/obesity was increased with higher added sugar intakes in the 4–8 year old children.

Association between insulin-like growth factor-1, measures of overnutrition and undernutrition and insulin resistance in black adolescents living in the north-west province, South Africa

To determine if insulin‐like growth factor‐1 (IGF‐1) is a significant predictor of body fat percentage (%BF), lean body mass, and insulin resistance (IR) in black adolescents presenting with overnutrition and undernutrition.

Community health workers can play an important role in the prevention and control of non-communicable diseases in poor communities

Countries in transition, such as South Africa, are particularly affected by the increased prevalence of obesity across all economic levels and age groups. Shifts in dietary intake and physical activity patterns to higher fat intake and inactivity are thought to be contributing factors. Prevention and treatment of obesity is therefore necessary to prevent the development of non-communicable diseases (NCDs). Such interventions should be based on education, behaviour change, community participation and local action. In this regard, adequately resourced prevention and intervention programmes should be planned, monitored and evaluated properly.A JC N Countries in transition, such as South Africa, are particularly affected by the increased prevalence of obesity across all economic levels and age groups. Shifts in dietary intake and physical activity patterns to higher fat intake and inactivity are thought to be contributing factors. Prevention and treatment of obesity is therefore necessary to prevent the development of non-communicable diseases (NCDs). Such interventions should be based on education, behaviour change, community participation and local action. In this regard, adequately resourced prevention and intervention programmes should be planned, monitored and evaluated properly. There is an unacceptable gap between knowledge on the development of risk factors associated with NCDs and the translation of this knowledge into successfully implemented intervention programmes. The article by Puoane et al. in the current issue of SAJCN is a good example of a community intervention planned as a partnership between an academic research group and community health workers (CHWs) from the community.