Rozanne Kruger

The determinants of overweight and obesity among 10- to 15-year-old schoolchildren in the North West Province, South Africa – the THUSA BANA (Transition and Health during Urbanisation of South Africans; BANA, children) study

AIM To investigate the determinants of overweight and obesity among 10- to 15-year-old schoolchildren in a population in the transitional phase in the North West Province of South Africa. METHODS A cross-sectional survey was used to investigate weight status (anthropometric indicators) and determinants of overweight/obesity including dietary intake, physical activity and socio-economic status. A single, random sample (n=1257), stratified for gender, type of school and ethnic group, was used. Data were collected on demographics, family circumstances, habitual physical activity, dietary intake and anthropometry to evaluate weight status and body fat content. One-way analysis of variance, the generalised linear models procedure of SAS and the Tukey post hoc honest significant difference test were used to analyse the data. RESULTS Few children were overweight or obese (7.8%) according to International Obesity Task Force (IOTF) standards (body mass index (BMI)-for-age). These standards were compared with other accepted standard values. Both Coles IOTF/BMI-for-age standard and the sum of skinfold thicknesses standard classified normal-weight status similarly at a level of 92% (P<0.01) and were found to be useful in determining overweight/obesity. The prevalence rate was higher in females and white children, and was more apparent in urban areas, smaller households and children of parents with low- or high-income occupations. Boys and pre-menarcheal girls had mean body fat percentage in the normal/optimal range, whereas that of post-menarcheal girls was moderately high. Few variables showed a significant association with high body fat percentage: in boys, only the number of members in the household and physical activity levels over the weekend; in girls, only age. The overweight/obese boys mostly lived in smaller households, and the overweight/obese post-menarcheal girls were most inactive on both weekdays and weekends, and more overweight with increasing age. CONCLUSION Smaller households, inactivity and increasing age for girls were found to be determinants that influence the development of overweight/obesity, while female gender and age post-menarche were identified as determinants of higher body fat content. For overweight/obesity prevention, the focus should be on pre-menarcheal girls, aged 10-13 years, using these determinants to identify overweight/obesity risk. Preventive programmes should aim to increase the physical activity of children to improve their current and future weight status.

A qualitative exploration of rural feeding and weaning practices, knowledge and attitudes on nutrition

AIM An exploratory qualitative investigation was done to determine the feeding and weaning practices, knowledge and attitudes towards nutrition of mothers/caregivers of children up to 3 years old attending baby clinics in the Moretele district (South Africa). METHODOLOGY Qualitative data collection on six relevant nutrition topics was done using focus group interviews. Trained moderators, using a pre-tested, structured interview schedule, interviewed participants in six age groups. Focus group interviews were taped, transcribed and translated. Content analysis produced systematic data descriptions and ethnography provided descriptive data. RESULTS Breast-feeding was the choice feed and bottle-feeding was only given when breast-feeding was impossible. Solid food was introduced early (at 2-3 months) and a mixed family diet at 7-9 months. Milk feeds were stopped completely from 18-24 months. Weaning diets were compromised due to poor food choices, preparation practices and limited variety. The participants nutrition knowledge regarding specific foods, their functions and recommended quantities was poor. The women adhered to their cultural beliefs regarding food choices and preparation practices. CONCLUSION The data analysis revealed that inadequate nutrition knowledge and adherence to cultural practices lead to poor-quality feeding practices. Cultural factors and taboos have a powerful influence on feeding practices and eating patterns. Young mothers often find it impossible to ignore their ill-informed elders or peer group. Nutrition knowledge needs to be changed in a first step towards implementing improved feeding practices. Facilitated group discussions could focus on possible solutions for the identified nutrition-related problems.

Food Variety and Dietary Diversity as Indicators of the Dietary Adequacy and Health Status of an Elderly Population in Sharpeville, South Africa

ABSTRACT This cross-sectional, analytical study was a comprehensive health assessment focusing on dietary quality of 170 randomly selected elderly respondents in Sharpeville, South Africa. The methods included a sociodemographic, health food frequency questionnaire, 24 h-recall questionnaires, and anthropometric and biochemical measurements. The low mean±standard deviation (SD) dietary diversity score (3.41±1.34) and food variety score (4.77±2.2) compared with poverty parameters confirmed household food insecurity in this community. Although three (n = 99, 58.6%) or two (n = 49, 28.9%) daily meals were mostly consumed, these were mainly carbohydrate-based and nutrient-deficient. The cereal group (2.01±0.81) had the highest mean food variety score ±SD, followed by dairy (0.62±0.53) and flesh foods (0.40±0.53). When a mean adequacy ratio of 70% was used as a cut-off point for nutrient adequacy, it was found that the food variety score must be eight or higher and the dietary variety score must be at least six. These indicators thus have a high ability to identify those respondents with an inadequate diet but lower ability to identify those respondents with a nutritionally adequate diet. The data further showed a trend that with a higher food variety and dietary diversity, a better mean adequacy ratio is reached for this low-income group of elderly subjects. In conclusion, the results showed that food variety and dietary diversity scores give a fairly good assessment of the adequacy of the diet, and scoring dietary diversity is a significant, yet simple tool to identify elderly persons at risk of food and nutrition insecurity.

Dietary diversity and adequacy of women caregivers in a peri-urban informal settlement in South Africa

OBJECTIVE Simple measures reflecting dietary quality are preferred for assessment of dietary intakes in low-income communities, e.g. dietary diversity that reflects a healthy, varied, nutritious diet, associated with nutrient adequacy. A strong association between household income and food access suggests dietary diversity assessment as one of the indicators of household food security. The aim of this study was to assess the food security situation of black women in an informal settlement by exploring their food access capabilities through dietary diversity measures and the coping strategies they employ to cope with poverty and hunger. METHODS A randomly selected sample of black women living in an informal settlement completed a pretested socio-demographic questionnaire (socio-economic circumstances) and validated questionnaires (1-wk quantified food frequency questionnaire: diversity measures; 24-h recall: nutrient intake; Cornell Hunger Scale: coping strategies). Food variety scores and food group diversity scores were calculated from frequency analyses for all foods and food groups. Nutrient adequacy ratios for various nutrients and the mean adequacy ratio for their diet were calculated. Relationships between dietary diversity and nutritional adequacy were investigated with Pearson correlations. Food variety score cut points were tested for sensitivity and specificity against nutritional adequacy. RESULTS Intakes were deficient for all nutrients except carbohydrates. Individual mean ± SD nutrient adequacy ratios ranging between 0.15 ± 0.18 and 0.95 ± 0.19 confirmed the poor dietary quality. Zero to 40 individual foods were consumed, but the mean ± SD food variety score was only 3.17 ± 1.21, indicating low food diversity, as did the low dietary diversity score (2.82 ± 0.99) using 0 to 6 food groups. CONCLUSIONS Limited food access and food variety in poor households resulted in inadequate nutrient intakes (low nutrient adequacy ratios), confirmed by poor dietary diversity (food variety score and food group diversity score). Dietary diversity assessment can successfully replace traditional dietary assessment tools in poverty-stricken or low-income communities where quick assessments are often required to assess the greatest need.

Vegetarianism, vitamin B12 status, and insulin resistance in a group of predominantly overweight/obese South Asian women

OBJECTIVES Asian Indians are an at-risk group for vitamin B12 deficiency (because of vegetarianism) and insulin resistance (IR). Vegetarianism and consequent vitamin B12 deficiency may be associated with IR. This study aimed to describe the vitamin B12 status of predominantly overweight/obese women of South Asian origin living in Auckland and to correlate serum vitamin B12 and vegetarian status with IR as part of the larger Surya Study looking at health and lifestyle in this population. METHODS This was a cross-sectional study of 135 women at least 20 y of age who were not taking vitamin B supplements or medications that could affect vitamin B12 concentrations (serum vitamin B12 < 800 pmol/L). Data collection included serum vitamin B12, serum folate, measurements of IR (HOMA2-IR), and anthropometry. Vegetarian status was established for 124 subjects (90 non-vegetarians, 34 vegetarians). RESULTS Mean serum vitamin B12 was 227 pmol/L (95% confidence interval 210-245), serum folate was 19.1 nmol/L (18.0-20.2), and HOMA2-IR was 1.24 (1.13-1.36). Non-vegetarians had higher serum vitamin B12 levels (257 pmol/L, 235-281) than vegetarians (181 pmol/L, 159-207), P < 0.001. Vitamin B12 deficiency (<150 pmol/L) in vegetarians was 24% versus 9% in non-vegetarians. Non-vegetarians had increased body mass index (25.9 kg/m², 25.0-26.9, versus 23.9 kg/m², 22.6-25.3), waist circumference (81 ± 10.1 versus 75.8 ± 9.88 cm), and HOMA2-IR levels (1.30, 1.17-1.46, versus 1.00, 0.83-1.22). No correlation was found between serum vitamin B12 and HOMA2-IR. A significant positive correlation between non-vegetarian status and IR disappeared after controlling for body mass index. CONCLUSIONS This study population has a low serum vitamin B12 status, especially if vegetarian. The high rates of observed obesity may have overshadowed any other contributing factor to IR.

Dietary Determinants of and Possible Solutions to Iron Deficiency for Young Women Living in Industrialized Countries: A Review

Iron deficiency is a concern in both developing and developed (industrialized) countries; and young women are particularly vulnerable. This review investigates dietary determinants of and possible solutions to iron deficiency in young women living in industrialized countries. Dietary factors including ascorbic acid and an elusive factor in animal protein foods (meat; fish and poultry) enhance iron absorption; while phytic acid; soy protein; calcium and polyphenols inhibit iron absorption. However; the effects of these dietary factors on iron absorption do not necessarily translate into an association with iron status and iron stores (serum ferritin concentration). In cross-sectional studies; only meat intake has consistently (positively) been associated with higher serum ferritin concentrations. The enhancing effects of ascorbic acid and meat on iron absorption may be negated by the simultaneous consumption of foods and nutrients which are inhibitory. Recent cross-sectional studies have considered the combination and timing of foods consumed; with mixed results. Dietary interventions using a range of focused dietary measures to improve iron status appear to be more effective than dietary approaches that focus on single nutrients or foods. Further research is needed to determine optimal dietary recommendations for both the prevention and treatment of iron deficiency.

Validity and reliability of bioelectrical impedance analysis to estimate body fat percentage against air displacement plethysmography and dual-energy X-ray absorptiometry

Air displacement plethysmography (ADP) and dual-energy X-ray absorptiometry (DXA) are well-regarded methods for predicting body fat percentage (BF%). Bioelectrical impedance analysis (BIA) also predicts BF% and has distinct advantages in research settings. Aim To assess the validity of BIA against ADP and DXA to measure BF%, and to test the reliability of each method. Methods Adults (n = 166) with a wide range of body mass index (19–38 kg/m2) were tested twice during a 5-day period. ADP was conducted in a BodPod (Life Measurement Inc, Concord, CA, USA); DXA measurements on a QDR Discovery A (Hologic) and BIA measurements used the InBody 230 (Biospace Ltd., Seoul, Korea). Agreement between measurements was analysed using t-tests, effect size, linear regression models and method of triads (estimating true value). Results BIA showed excellent relative agreement to the estimated true value (ρ = 0.97 (0.96, 0.98)) and to ADP (R2 = 0.88) and DXA (R2 = 0.92), but wide limits of agreement (−4.25 to 8.37%). BIA underestimated BF% by 2%, across all values. DXA showed excellent relative agreement to the estimated true value (ρ = 0.97 (0.96, 0.98)) and with ADP (R2 = 0.92), good absolute agreement but wide limits of agreement (−6.13 to 6.91%) and under- and overestimation at high and low BF% levels, respectively. All methods showed excellent reliability with repeat measurements differing by less than 0.2% with very small 95% CIs. Conclusions BIA may be a valid method in research and population samples. All three methods showed excellent reliability.

Kiwifruit consumption favourably affects plasma lipids in a randomised controlled trial in hypercholesterolaemic men

The unique composition of green kiwifruit has the potential to benefit CVD risk. The aim of the present study was to investigate the effect of consuming two green kiwifruits daily in conjunction with a healthy diet on plasma lipids and other metabolic markers and to examine response according to APOE genotype in hypercholesterolaemic men. After undergoing a 4-week healthy diet, eighty-five hypercholesterolaemic men (LDL-cholesterol (LDL-C) > 3.0 mmol/l and TAG < 3 mmol/l) completed an 8-week randomised controlled cross-over study of two 4-week intervention sequences of two green kiwifruits per d plus healthy diet (intervention) or healthy diet alone (control). Anthropometric measures, blood pressure (BP) and fasting blood samples (plasma lipids, serum apoA1 and apoB, insulin, glucose, high-sensitivity C-reactive protein (hs-CRP)) were taken at baseline, and at 4 and 8 weeks. After the kiwifruit intervention, plasma HDL-cholesterol (HDL-C) concentrations were significantly higher (mean difference 0.04; 95% CI 0.01, 0.07 mmol/l; P = 0.004) and the total cholesterol (TC):HDL-C ratio was significantly lower (mean difference 20.5; 95% CI 20.24, 20.05 mmol/l; P = 0.002) compared with the control. In carriers of the APOE4 allele, TAG decreased significantly (mean difference -0.18; 95% CI -0.34, -0.02 mol/l; P = 0.03) with kiwifruit compared with control. There were no significant differences between the two interventions for plasma TC, LDL-C, insulin, glucose, hs-CRP and BP. The small but significant increase in HDL-C and decrease in TC:HDL-C ratio and TAG (in APOE4 carriers) suggest that the regular inclusion of green kiwifruit as part of a healthy diet may be beneficial in improving the lipid profiles of men with high cholesterol.

Food-Coping Strategy Index Applied to a Community of Farm-Worker Households in South Africa

Background In South Africa, households living in informal urban settlements, in rural areas, and on commercial farms experience various levels of dietary variety, food intake, and household hunger. Low incomes, poor food production and availability, and low spending power characterize these households. Households employ various food-coping strategies to alleviate food stress or poor food availability. Objective To apply an existing food-coping strategy (FCS) index to assess household hunger and its usefulness in identifying the level of food stress and the patterns of food coping in farm-worker households. Methods A cross-sectional survey was conducted. Data were gathered from women (18 to 57 years of age) responsible for food provision in a small farm-worker community in Fouriesburg, South Africa. A structured food-coping questionnaire and a standardized FCS index were used to gather data. Results The two most common FCS used were relying on cheaper food (chicken feet, diluted soya-mince soup) or less preferred food (meat bones) and employing food-seeking strategies (gathering wild foods), followed by consumption of seed stock (maize) and reduced portion sizes (protein foods and side dishes), resulting in starch-based diets of poor variety. Seasonal strategies varied according to the level of food stress experienced. Patterns of food coping were identified. Conclusions Negative FCS (limiting food choices, only consuming starchy staples) may cause poor health status. The FCS index was effectively used to assess farm-worker household food-coping behavior (early, clear signals of the level of food distress). These results could be used to allocate appropriate food aid (type of food) and to design nutrition education programs focused on positive FCS (food gathering or bartering) in a particular community to prevent suboptimal nutritional status.

The effect of gold kiwifruit consumed with an iron fortified breakfast cereal meal on iron status in women with low iron stores: A 16 week randomised controlled intervention study

BackgroundDietary treatment is often recommended as the first line of treatment for women with mild iron deficiency. Although it is well established that ascorbic acid enhances iron absorption, it is less clear whether the consumption of ascorbic acid rich foods (such as kiwifruit) with meals fortified with iron improves iron status. The aim of this study is to investigate whether the consumption of ZESPRI® GOLD kiwifruit (a fruit high in ascorbic acid and carotenoids) with an iron fortified breakfast cereal meal increases iron status in women with low iron stores.Methods/DesignEighty nine healthy women aged 18-44 years with low iron stores (serum ferritin (SF) ≤ 25 μg/L, haemoglobin (Hb) ≥ 115 g/L) living in Auckland, New Zealand were randomised to receive an iron fortified breakfast cereal (16 mg iron per serve) and either two ZESPRI® GOLD kiwifruit or a banana (low ascorbic acid and carotenoid content) to eat at breakfast time every day for 16 weeks. Iron status (SF, Hb, C-reactive protein (CRP) and soluble transferrin receptor (sTfR)), ascorbic acid and carotenoid status were measured at baseline and after 16 weeks. Anthropometric measures, dietary intake, physical activity and blood loss were measured before and after the 16 week intervention.DiscussionThis randomised controlled intervention study will be the first study to investigate the effect of a dietary based intervention of an iron fortified breakfast cereal meal combined with an ascorbic acid and carotenoid rich fruit on improving iron status in women with low iron stores.Trial registrationACTRN12608000360314