Across Australia and other developed nations, morbidity and mortality follows a socioeconomic gradient whereby the lowest socioeconomic groups experience the poorest health. The dietary practices of low socioeconomic groups, which are comparatively less consistent with dietary recommendations, have been thought to contribute to the excess morbidity and mortality observed among low socioeconomic groups, although this phenomenon is not well understood. Using a socioecological framework, this thesis examines whether the local food retail environment and confidence to cook contribute to socioeconomic differences in fruit and vegetable purchasing. To achieve this, four quantitative analyses of data from two main sources were conducted. The food retail environment was examined via secondary analysis of the Brisbane Food Study (BFS) and confidence to cook was examined in a cross-sectional study designed and carried out by the author.
The first three manuscripts were based on findings from the BFS. Briefly, the BFS was a multilevel cross-sectional study, designed to examine determinants of inequalities, that was conducted in Brisbane in the year 2000. A stratified random sample was taken of 50 small areas (census collection districts, CCDs) and 1003 residents who usually shopped for their households were interviewed face-to-face using a schedule that included a measure of fruit and vegetable purchasing and three socioeconomic markers: education, occupation and gross household income. The purchasing measure was based on how often (never, rarely, sometimes nearly always or always) participants bought common fruits and vegetables for their households in fresh or frozen form, when in season. Food shops within a 2.5 km radius of the CCDs in which survey respondents lived were identified and audited to determine their location, type, their opening hours, and their price and availability of a list of food items.
The first publication demonstrated there was minimal to no difference in the availability of supermarkets, greengrocers and convenience stores between areas that were most and least disadvantaged, in terms of the number of shops, distance to the nearest shop, or opening hours. Similarly, the second publication showed the most disadvantaged and least disadvantaged areas had no large or significant difference in the price and availability of fruits and vegetables within supermarkets, greengrocers and convenience stores, but small differences were consistently apparent, such that on average, low socioeconomic areas had lower prices but also lesser availability than more advantaged areas. The third submitted manuscript presents results of multilevel logistic regression analyses of the BFS data. While there were some associations between environmental characteristics and fruit and vegetable purchasing, environmental characteristics did not mediate socioeconomic differences in purchasing the fruit and vegetable items since there was no substantial socioeconomic patterning of the price or availability of fruits and vegetables.
The fourth submitted manuscript was based on the cross-sectional study of cooking skills. A stratified random sample of six CCDs in Brisbane was taken and 990 household members ‘mostly responsible’ for preparing food were invited to participate. A final response rate of 43% was achieved. Data were collected via a self-completed questionnaire, which covered household demographics, vegetable purchasing (using the same measure employed in the BFS for continuity), confidence to prepare these same vegetables, and confidence to cook vegetables using ten cooking techniques. Respondents were asked to indicate how confident they felt (ranging from not at all- to very- confident) to prepare each vegetable, and to use each technique. This fourth study found respondents with low education and low household income had significantly lower confidence to cook than their higher socioeconomic counterparts, and lower confidence to cook was in turn associated with less household vegetable purchasing.
Collectively, the four manuscripts comprising this thesis provide an understanding of the contribution of food accessibility, affordability and cooking skills to socioeconomic differences in fruit and vegetable purchasing, within a socioecological framework. The evidence provided by this thesis is consistent with a contributory role of confidence to cook in socioeconomic differences in fruit and vegetable purchasing, but is not definitive. Additional research is necessary before promoting cooking skills to improve population nutrition or reduce nutritional inequalities. An area potentially useful to examine would be how cooking skills integrate with psychosocial correlates of food and nutrition, and socioeconomic position. For example, whether improvement of cooking skills can generate interest and knowledge, and improve dietary behaviours, and whether a lack of interest in food and nutrition contributes to a lack of both fruit and vegetable consumption and cooking skills. This thesis has demonstrated that an inequitably distributed food retail environment probably does not contribute to socioeconomic variation in fruit and vegetable purchasing, at least in contemporary Brisbane, Australia. Findings are unlikely to apply to other time periods, rural and regional settings, and perhaps other Australian cities as residential and retail development, and the supply and pricing of produce vary substantially across these dimensions. Overall, the main implication for public health is that interventions targeting the food supply in terms of ensuring greater provision of shops, or altering the available food and prices in shops may not necessarily carry a great benefit, at least in major cities similar to Brisbane. Future studies of equitable food access may need to look beyond mapping the distribution of shops and prices, perhaps to more personal and subjective facets of accessibility and affordability that incorporate individuals’ perceptions and ability to access and pay for foods.
| Identifer | oai:union.ndltd.org:ADTP/265715 |
| Date | January 2008 |
| Creators | Winkler, Elisabeth Amy |
| Publisher | Queensland University of Technology |
| Source Sets | Australiasian Digital Theses Program |
| Detected Language | English |
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