Fast food purchasing and access to fast food restaurants : a multilevel analysis of VicLANES

Background : While previous research on fast food access and purchasing has not found evidence of an association, these studies have had methodological problems including aggregation error, lack of specificity between the exposures and outcomes, and lack of adjustment for potential confounding. In this paper we attempt to address these methodological problems using data from the Victorian Lifestyle and Neighbourhood Environments Study (VicLANES) – a cross-sectional multilevel study conducted within metropolitan Melbourne, Australia in 2003.
Methods : The VicLANES data used in this analysis included 2547 participants from 49 census collector districts in metropolitan Melbourne, Australia. The outcome of interest was the total frequency of fast food purchased for consumption at home within the previous month (never, monthly and weekly) from five major fast food chains (Red Rooster, McDonalds, Kentucky Fried Chicken, Hungry Jacks and Pizza Hut). Three measures of fast food access were created: density and variety, defined as the number of fast food restaurants and the number of different fast food chains within 3 kilometres of road network distance respectively, and proximity defined as the road network distance to the closest fast food restaurant. Multilevel multinomial models were used to estimate the associations between fast food restaurant access and purchasing with never purchased as the reference category. Models were adjusted for confounders including determinants of demand (attitudes and tastes that influence food purchasing decisions) as well as individual and area socio-economic characteristics.
Results : Purchasing fast food on a monthly basis was related to the variety of fast food restaurants (odds ratio 1.13; 95% confidence interval 1.02 – 1.25) after adjusting for individual and area characteristics. Density and proximity were not found to be significant predictors of fast food purchasing after adjustment for individual socio-economic predictors.
Conclusion : Although we found an independent association between fast food purchasing and access to a wider variety of fast food restaurant, density and proximity were not significant predictors. The methods used in our study are an advance on previous analyses.

Clinical waste management in Victorian hospitals

This project for the Doctor of Technology provides a significant contribution to the understanding of healthcare waste management in Victoria and worldwide. The thesis describes approaches to enable healthcare facilities to identify factors that contribute to waste generation and resulting impacts on the environment in order to reduce them.

Australian rock coasts : review and prospects

Studies of Australian rock coasts (except carbonate reefs) are reviewed and considered in view of recent process and morphological studies. The unique nature of the Australian coast, its geographical distribution and relative stability mean that it is a productive environment in which to research fundamental questions concerning rock coasts. Future research directions are identified, specifically in the areas of processes, morphology and modelling.

Individual and area-level socioeconomic associations with fast food purchasing

Background It has been suggested that those with lower socioeconomic characteristics would be more likely to seek energy-dense food options such as fast food because of cheaper prices; however, to date the evidence has been inconsistent. This study examines both individual- and area-level socioeconomic characteristics and their independent associations with chain-brand fast food purchasing.

Methods Data from the 2003 Victorian Lifestyle and Neighbourhood Environments Study (VicLANES); a multilevel study of 2547 adults from 49 small-areas in Melbourne, Australia, were used. Multilevel multinomial models adjusted for confounders were used to assess associations between individual socioeconomic position (education, occupation and income) and area socioeconomic characteristics in relation to fast food purchasing from five major fast food chains with outcome categories: never, at least monthly and at least weekly. The study finally assessed whether any potential area-level associations were mediated by fast food access.

Results Increased fast food purchasing was independently associated with lower education, being a blue-collar employee and decreased household income. Results for area-level disadvantage were marginally insignificant after adjustment for individual-level characteristics, although they were suggestive that living in an area with greater levels of disadvantage increased an individual's odds of more frequent fast food purchasing. This effect was further attenuated when measures of fast food restaurant access were included in the models.

Conclusion Independent effects of lower individual-level socioeconomic characteristics and more frequent fast food purchasing for home consumption are demonstrated. Although evidence was suggestive of an independent association with area-level disadvantage this did not reach statistical significance.

Fast food restaurant locations : could they be 'supersizing' local communities?

This review examines the current state of knowledge related to the location of fast food restaurants. Previous studies have revealed some communities are more exposed to fast food restaurants. However, the influence of increased exposure to fast food on dietary behaviours remains unresolved. This is identified as an area of priority for future research.

Who is eating where? Findings from the SESAW study

Objective: Foods prepared outside of the home have been linked to less-than-ideal nutrient profiles for health. We examine whether the locations where meals are prepared and consumed are associated with socio-economic predictors among women.
Design: A cross-sectional study using self-reported data. We examined multiple locations where meals are prepared and consumed: (i) at home; (ii) fast food eaten at home; (iii) fast food eaten at the restaurant; (iv) total fast food; (v) non-fast-food restaurant meals eaten at home; (vi) non-fast-food restaurant meals eaten at the restaurant; and (vii) all non-fast-food restaurant meals. Multilevel logistic regression was used to determine whether frequent consumption of meals from these sources varied by level of education, occupation, household income and area-level disadvantage.
Setting: Metropolitan Melbourne, Australia.
Subjects: A total of 1328 women from forty-five neighbourhoods randomly sampled for the SocioEconomic Status and Activity in Women study.
Results: Those with higher educational qualifications or who were not in the workforce (compared with those in professional employment) were more likely to report frequent consumption of meals prepared and consumed at home. High individual and area-level socio-economic characteristics were associated with a lower likelihood of frequent consumption of fast food and a higher likelihood of frequent consumption of meals from non-fast-food sources. The strength and significance of relationships varied by place of consumption.
Conclusions: The source of meal preparation and consumption varied by socioeconomic predictors. This has implications for policy makers who need to continue to campaign to make healthy alternatives available in out-of-home food sources.

Neighbourhood-socioeconomic variation in women's diet : the role of nutrition environments

Background/Objectives: Living in socioeconomically disadvantaged neighbourhoods is associated with increased risk of a poor diet; however, the mechanisms underlying associations are not well understood. This study investigated whether selected healthy and unhealthy dietary behaviours are patterned by neighbourhood-socioeconomic disadvantage, and if so, whether features of the neighbourhood–nutrition environment explain these associations.

Subjects/Methods: A survey was completed by 1399 women from 45 neighbourhoods of varying levels of socioeconomic disadvantage in Melbourne, Australia. Survey data on fruit, vegetable and fast-food consumption were linked with data on food store locations (supermarket, greengrocer and fast-food store density and proximity) and within-store factors (in-store data on price and availability for supermarkets and greengrocers) obtained through objective audits. Multilevel regression analyses were used to examine associations of neighbourhood disadvantage with fruit, vegetable and fast-food consumption, and to test whether nutrition environment factors mediated these associations.

Results: After controlling for individual-level demographic and socioeconomic factors, neighbourhood disadvantage was associated with less vegetable consumption and more fast-food consumption, but not with fruit consumption. Some nutrition environmental factors were associated with both neighbourhood disadvantage and with diet. Nutrition environmental features did not mediate neighbourhood-disadvantage variations in vegetable or fast-food consumption.

Conclusions: Although we found poorer diets among women living in disadvantaged neighbourhoods in Melbourne, the differences were not attributable to less supportive nutrition environments in these neighbourhoods.

'Forbidden' disulfides : their role as redox switches

Seminal studies by Richardson and Thornton defined the constraints imposed by protein structure on disulfide formation and flagged forbidden regions of primary or secondary structure seemingly incapable of forming disulfide bonds between resident cysteine pairs. With respect to secondary structure, disulfide bonds were not found between cysteine pairs: A. on adjacent beta-stands; B. in a single helix or strand; C. on non-adjacent strands of the same beta-sheet. In primary structure, disulfide bonds were not found between cysteine pairs: D. adjacent in the sequence. In the intervening years it has become apparent that all these forbidden regions are indeed occupied by disulfide-bonded cysteines, albeit rather strained ones. It has been observed that sources of strain in a protein structure, such as residues in forbidden regions of the Ramachandran plot and cis-peptide bonds, are found in functionally important regions of the protein and warrant further investigation. Like the Ramachandran plot, the earlier studies by Richardson and Thornton have identified a fundamental truth in protein stereochemistry: "forbidden" disulfides adopt strained conformations, but there is likely a functional reason for this. Emerging evidence supports a role for forbidden disulfides in redox-regulation of proteins.