3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item The association of nutrition on body composition and metabolic disease risk in rural South Africa children and adolescents(2017) Pedro, Titilola MinsturatBackground: The persistent burden of undernutrition, with increasing prevalence of obesity and metabolic disease risk among children and adolescents, has become a global public health problem. Research has shown that risk factors established in childhood and adolescence may contribute to the development of non-communicable diseases (NCDs) in adulthood. This is of particular concern in South Africa, given its rapid socio-economic, political and epidemiological transitions. Research into the trends of nutrition transition in rural children and adolescents, whose particular health needs have been under-served and poorly delineated in the past, provides a unique opportunity to study the e ects of rapid health transitions on development. Aim: To determine the association of nutrition, body composition and metabolic disease risk in rural South African children and adolescents. Study design: Three cross-sectional studies were undertaken to address the overall aim of this research. The speci c objectives of each study were: (1) to determine the association of nutrition on body composition and metabolic disease risk in children and adolescents; (2) to examine the associations between body mass index (BMI), disordered eating attitude and body dissatisfaction in female adolescents, and descriptive attributes assigned to silhouettes of di ering body habitus in male and female adolescents; and (3) to investigate associations between diet and cardiovascular disease (CVD) risk factors in adolescents. Method: One cross-sectional study, 3 analyses were nested within the Agincourt Health and Socio-demographic Surveillance System (HDSS) site, in the Bushbuckridge subdistrict, Mpumalanga Province, South Africa. In 2009, a random sample of 600 children and adolescents, from age groups 7 to 8 years, 11 to 12 years and 14 to 15 years, were selected from 3489 children who had participated in a 2007 growth survey. These children and adolescents had to have lived in Agincourt at least 80% of the time since birth or since 1992, when enrolment into the Agincourt Health and Socio-Demographic Surveillance System (HDSS) began. Height and weight were measured to determine BMI. Age and sex-speci c cut-o s for underweight and overweight/obesity were determined using those of the International Obesity Task Force. Body image satisfaction using Feel-Ideal Discrepancy (FID) scores, Eating Attitudes Test-26 (EAT-26), perceptual female silhouettes and pubertal assessment were collected through self-administered questionnaires. Blood pressure (systolic (SBP) and diastolic (DBP)) was measured, fasting blood samv ples were collected for the determination of glucose and lipids. Waist to hip ratio cut-o s of (WHR) >0.85 for females, >0.90 for males, waist to height ratio (WHtR) of >0.5 for both sexes, and waist circumference (WC) of >80 cm for females and >94 cm for males were used to determine the risk of adiposity. For abnormal lipids: high density lipoprotein cholesterol (HDL-C) cut-o s of >1.03 mmol/l, low density lipoprotein-cholesterol (LDL-C) of >2.59 mmol/l, triglycerides (TGs) of >1.7 mmol/l and total cholesterol (TC) of >5.17 mmol/l were used. Pre-hypertension prevalence was computed using the average of 2 readings of SBP or DBP, being >90th but <95th percentile for age, sex and height. Dietary intake was assessed using semi-quantitative food frequency questionnaire. T-test and ANOVAs for normally distributed data and Wilcoxon-Mann- Whitney test was used to determine signi cant di erences by sex and by pubertal stages for EAT-26 and EAT-26 sub-scores. Chi square tests were done to determine signi cant associations between the categorical variables. Bivariate linear regression was employed to test associations and signi cant tests were set at the p<0.05 level. Results: Study component (1): Stunting levels were higher in the boys than in the girls in mid to late childhood and combined overweight and obesity prevalence was higher in girls than in boys. The girls' BMI was signi cantly greater at ages 11 and 12 years than that of the boys [girls: 18 3.4, 95% con dence interval (CI): 17.33- 18.69; boys: 17 2, 95% CI: 16.46-17.25; p-value 0.004] and at ages 14-15 years (girls: 22 4.1, 95% CI: 20.82-22.47; boys: 19 2.4, 95% CI: 18.39-19.38; p-value < 0.001). Prehypertension (de ned as < 90th centile for age, sex and height) was higher in girls (15%) than boys (10%). Further, impaired fasting glucose was detected in 5.3% of girls and 5% of boys. High-density lipoprotein cholesterol (>1.03 mmol/l) concentrations were observed in 12% of the girls and 0.7% of the boys, which is indicative of cardiometabolic risk. Study component (2): The prevalence of overweight and obesity was higher in girls than boys in early and mid to post pubertal stages. The majority (83.5%) of the girls reported body image dissatisfaction (a desire to be thinner or fatter). The girls who wanted to be fatter had a signi cantly higher BMI than the girls who wanted to be thinner (p=0.001). There were no di erences in EAT-26 score between pubertal groups, or between boys and girls within the two pubertal groups. The majority of the boys and the girls in both pubertal groups perceived the underweight silhouettes to be \unhappy" and \weak" and the majority of girls in both pubertal groups perceived the normal silhouettes to be the \best". Study component (3): Added sugar and sweets contributed 10% and maize meal and vi bread contributed 7.2% to the total number of food items consumed respectively. Girls had higher intakes of total fat, saturated fat and cholesterol after adjusting for dietary energy intake and age (all p<0.001). The prevalence of combined overweight and obesity was 13.8% in girls and 3.1% in boys (p<0.001). In addition, indicators of adiposity were higher in females, abnormal waist circumference (WC) (6.7%), waist to hip ratio (WHR) (22.0%) and waist to height ratio (WHtR) (18.0%), compared to males, (0%), (3.1%) and (6.2%) respectively (all p<0.001). Girls had higher low-density lipoprotein (LDL) (12(9.3%) vs. 3(2.3%), p=0.01), total cholesterol (17(12.7%) vs. 5(3.5%), p<0.001) and were more pre-hypertensive (28(15.3%) vs.15(8.4%), p=0.04) than the boys. Furthermore, the bivariate associations between dietary intakes (total energy, total carbohydrate (CHO), total dietary fat and saturated fat) and anthropometric indices (BMI and WC) showed that body mass index (BMI) was associated with total energy (p=0.05) and BMI and WC were associated with total fat (p=0.01, p=0.03) and saturated fat (p<0.001, p=0.02) in females respectively. Conclusions: In conclusion, this thesis highlights that girls in rural South Africa had a higher prevalence of combined overweight and obesity than did boys, stunting was more prevalent amongst boys than girls in mid to late childhood and metabolic risk factors that were associated with adiposity, and linked to diet, were higher in girls than in boys. This study has provided useful information for targeting critical health promotion intervention programmes to optimise child nutrition as part of a noncommunicable disease preventative strategy, especially, in remote areas in rapidly transitioning South Africa.Item Comparison of individual food item intakes of a true longitude group of South African children at five interceptions between 1995 and 2003; The Birth-to-Twenty (BT-20) Study(2006-11-01T11:46:10Z) Pedro, Titilola MinsturatEating patterns change over time. Studies have been conducted in industrialized countries stating that it is important to study the longitudinal development of dietary intake itself and to determine the stability of this intake, but monitoring longitudinal dietary habits of the same children over a period of time, in particular with regard to individual food items, is severely limited in developing countries such as South Africa. South Africa, a country with diverse cultures, is undergoing massive socio-economic and political changes, and an increasing social integration following the abolishment of the previous apartheid legislation. Obviously diet too must have been affected. The country is in a state of nutritional transition, and if the nutritional status of South African children is to improve in the 21st century, basic knowledge is required of the actual food items the children have been and are consuming, and the change in consumption of these individual food items during this transition. The Birth-to-Twenty (Bt-20) study is the continuation of Birth-to-Ten (BTT) study, which started in 1990 and plans to continue to 2010. It is the largest running cohort study on children’s development in Africa and also the first and only longitudinal study on the nutrient and individual food item intake of South African children, living in the Johannesburg/Soweto area of the Gauteng Province. This research will thus provide valuable, unique information on the individual food items consumed and change in consumption of these foods by South African children from the Bt20 study over an eight-year period (1995–2003). The overall objective of this study was to determine the variety and change in consumption of individual food items consumed by a true longitudinal group of urban black South African children from the Bt20 study in 1995; ’97, ’99, 2000 and 2003 when they were 5, 7, 9, 10 and 13 years of age, respectively. with the following sub-objectives: • To determine the number of times each food item was recorded by the longitudinal group of children. • To determine the percentage of children consuming the individual food items. • To determine the mean weekly frequency of consumption of the individual food items for all the children, as well as for only those children consuming the items. The study sample size comprised a true longitudinal group of urban black South African children (n = 143), from the Bt20 study that had nutrition information at all 5 interceptions (1995, 1997, 1999, 2000 and 2003). Data were collected at each interception using the same semi-quantitative food frequency questionnaire. Parents/guardians or the children themselves were asked by trained multi-lingual interviewers to indicate how frequently the listed food items were consumed. The food items were coded onto computer coding sheets using the South African Medical Research Council’s Food Composition Tables and Codes. Recorded or standard portions sizes were used based on the use of the National Research Institute for Nutritional Diseases(NRIND) Food Quantities Manual. The coded data were put on disk by a data capturing company and SAS was used for statistical analysis. Specific computer programmes were written to systematically re-arrange and merge the data by subject ID number. The final longitudinal sample with nutrition information at 5 interceptions was extracted by ID number as each child kept the same ID number for all interceptions. Frequencies were calculated for: 1. The number of times each food item was recorded per week, firstly for all five interceptions combined and secondly for each interception separately. The total number times each food item was recorded for all five interceptions combined was divided by the total number of times all food items at all five interceptions combined (23840) were recorded and expressed as a percentage. The total number of times each food item was recorded at each interception separately was divided by the total number of children in the group [n=143] and expressed as a percentage. 2. The total weekly frequency of consumption for each food item. The mean weekly frequency of consumption for each food item was calculated for all the children in the group [n=143] for each interception separately (total weekly frequency of consumption of each food item/total number of children [n=143] and then only for those in the group consuming the food items (total weekly frequency of consumption of each food item/number of times each food item was recorded for each interception. The food items were ranked in descending order according to: • their percentage contribution of the total number of times all food items at all five interceptions combined were recorded • the average number of times recorded for all five interceptions combined • the mean weekly frequency of consumption for all five interceptions combined. The ranked food items were then arranged within the 8 food groups listed in the questionnaire (chapters 3, 4, 5). Forty-one food items made up 1% or more of the total number of times all food items were recorded for all five interceptions combined. This was used as a cut-off point as all the other food items were recorded too infrequently to include. For this reason only these forty-one items will be discussed in chapter 3, 4 and 5 of this thesis. A total of 546 different food items were recorded 23840 times between 1995-2003. The highest number of food items recorded was in 1999 (124) and 2003 (123) both almost 23% of the total number of food items recorded when the children were nine and thirteen years old, respectively. Of this, 41 items contributed 1% or more of the total number of recordings. There was a decrease in the number of recordings from the grain and cereal group, fruits and vegetables and milk and milk products. However, among the meat and meat substitutes, the number of recordings for chicken and cheese increased over this time as did the number of recordings for margarine and ice-cream among the fats and oils. Among the miscellaneous group sugar, sweets, tea and carbonated beverages remained fairly stable over the 5 interceptions, but there was an increase in the number of recordings for crisps and chocolates from 2000 to 2003. Ninety percent or more of the children consumed rice, stiff maize-meal porridge, chicken, sugar, sweets and tea over the five interceptions. Fourteen food items were consumed by 75% or more of the children and 33% of these 41 items were consumed by 50% or more. All the top 41 food items were consumed by more than 33% of the children. Among grain/cereal group/breakfast cereal/porridges and other starches, the most frequently consumed food items were brown bread, stiff and soft maize-meal porridge, all being consumed between 4-6x/week for all the children as well as for only those consuming these items. Peanut butter, eggs and chicken were the most frequently consumed items among the meat and meat substitutes, 3-5x/week for all the children and for only children consuming these items. In the group of fruits and vegetables, fruit juice and mashed potato were consumed most frequently, but not everyday of the week either for all the children or for those consuming these items. Within fats and oils food group, cooking oil and butter were consumed most frequently (3-4x/week) for all the children and 5x/week for only those children who consumed these items. Full cream milk was the most frequently consumed food item (5-6x/week) among the group of milk and milk products for all the children as well as for only those consuming this item. Among the miscellaneous food items sugar (5-6x/week), sweets and tea (4-5x/week) were the most frequently consumed for all the children and between 5-7x/week for only those consuming these items. The dietary patterns of this longitudinal group of urban black South African children was far from the recommended South African Food-Based Dietary Guidelines (FBDGs), which was developed with the aim of making evidence-based nutrition and lifestyle messages to the public accessible, understandable, generalizable, acceptable in a cross-cultural context and feasible. Thus, this study has provided useful insights to guide the governmental parastatals, nutrition scientists and other interested cooperate bodies in promoting successful nutrition intervention strategies that will lead to healthy dietary habits among children and adolescents.