Browsing by Author "Bourne, Lesley Thelma"

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    Dietary intake in an urban African population in South Africa, with special reference to the nutrition transition
    (1996) Bourne, Lesley Thelma; Steyn, K; Jooste, P L; Hoffman, M N
    An assessment of the nutritional status of a representative sample of an urban African population has not previously been conducted, nor the extent to which the traditional diet has been abandoned for a western diet. To meet this end, a cross-sectional analytic study was carried out on a representative sample (N=1146) of the urban African population, aged 3 - 64 years in 1990. Particular attention was paid to specific at-risk groups viz. preschoolers (aged 3 - 6 years; N=163), adolescents (aged 15 - 18 years; N=119) and adults (19 - 44 years; N=649). The interrelationships of dietary intake with socio-economic status, demographic indicators as well as measures of urban exposure were also examined. A further aim was to determine the extent to which this rapidly urbanising population ' s macronutrient profile had shifted from a traditional towards a western atherogenic dietary pattern. This analytic study was nested in a community-based descriptive survey on risk factors for cardiovascular disease. A multi-staged, proportional sampling strategy was used. Quotas were used in the final stage of sampling, based on the age/sex distribution of a 1988 census conducted by the local authorities. Dietary data were collected by means of the 24-hour recall method, by Xhosa -speaking registered nurses who had received intensive training. Anthropometric measurements were taken, and blood samples were drawn according to standard procedures. Socio-demographic questions elicited information on the physical environment and facilities, educational level and employment status. Information was also elicited regarding urban exposure relating to lifetime migration history, thus incorporating retrospective temporality into the study des ign. From these data, an index of urban exposure was established by calculating the percentage of life spent in an urban environment. Univariate analyses of dietary, anthropometric and biochemical vitamin status were used for the descriptive components of the study of the three specific at-risk age categories. Bivariate analyses examined the effects of selected proxies of socio-economic status, and urban exposure on dietary intake. Finally, multiple linear regressions were performed on the preschoolers (N=163) and adult sample, aged 15 - 64 years (N=983) incorporating additional indicators of socio-economic status as predictors, and dietary intake data as outcome measures. Correspondence analysis further explored the relationships between dietary atherogenicity (using the Keys score) and other risk factors for degenerative disease.
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    A liquid consumption survey of individuals in greater Cape Town
    (1986) Bourne, Lesley Thelma; Watermeyer, G S; Klopper, J
    There is no published data for the per capita consumption of water of individuals in South Africa. A daily rounded volume of 2 litres per person is usually taken as a working estimate from world wide data. As part of ongoing epidemiological studies into potential health effects of changes in the water supply to greater Town, water consumption patterns were ascertained. As health effects are often spatially ascribed to the place of residence of a person, it was necessary to ascertain how much water was drunk at home as well as away from home. Water consumed was divided into three classes: (i) water consumed from the tap, (ii) commercial beverages and (iii) water bound in food. A review of methods of conducting dietary surveys indicated that a 24-hour recall would be the most appropriate method. Two surveys on total dietary intake utilizing a 24-hour recall were carried out (n = 2 000 persons for each survey), one in winter and the ether in summer. The design of the survey involved a cluster sample of households that were representative of the socio-economic and demographic structure of greater Cape Town. Three pretested types questionnaires were administered by trained interviewers: (i) a placement questionnaire to describe the household composition, (ii) a recall questionnaire for individual adults and children and (iii) a recall questionnaire for babies. Particular attention was paid to the accurate ascertainment of the volumes of food and drink consumed as well as their preparation to facilitate accurate analysis. The water content of each food item was calculated by a computer program that utilized computerized food composition tables. The water consumption data was analyzed by sex, age, population group, income and the season of the year. Detailed graphs and tables are provided. Results were also standardized to the population of greater Cape Town. It was found that the difference in consumption between the White and "Coloured" population groups was greater than the difference between those people of high and low-income groups. The mean total water intake for Whites was 2.19 litres per day, while for "Coloureds" it was 1.26 litres per day. There is no obvious bias to account for this difference. The figures for protein consumed by the two groups, which was used as a control, are consistent with values reported in the literature. Summer consumption was higher than that during winter. The ratio of tap water consumed at home to total liquid consumed was approximately 0.5.