Rozprawy doktorskie na temat „Obesity – Australia”

This thesis investigated how to improve early identification of childhood overweight and obesity in Australia. In a series of three studies, this research applied behavioural change theory to examine determinants to assessing children’s weight status in primary health care. The recommendations provided in this thesis aim to affect policy and practice so that children can be better supported in maintaining and improving their health and wellbeing.

Nearly two-thirds of Australians and up to half of all Chinese are overweight. Global obesity figures have tripled since 1975 (WHO, 2018b), which demonstrates that obesity is a major global health problem. It is critical to examine how print media represent obesity because they influence public understanding of the problem. It is also essential to determine ways to improve health journalism and health outcomes. While there is a significant body of literature that has examined representations of obesity in the Australian press through mixed approaches, there is a deficit of media research into how China’s press has represented this issue. This study investigated how obesity was represented in two national newspapers—China Daily and The Australian—between 2013 and 2018. Content analysis was performed to reveal the types and frequency of obesity-related news items regarding causes, determinants, impacts, solutions and sources. Additionally, discourse analysis was undertaken to qualitatively reveal the framing of obesity based on findings from the content analysis. China Daily was selected because it is China’s largest-selling national daily English-language newspaper, while The Australian is Australia’s largest daily national newspaper. More than 1000 news items on obesity published in the two newspapers between 2013 and 2018 were retrieved through Factiva. Content analysis uncovered that obesity was under-presented in both newspapers. Individual causes and solutions were the most prominent news items in both newspapers, whereas genetic and biological determinants were less likely to be presented. For childhood obesity, parental determinants appeared more often than social determinants. Findings from the discourse analysis found three prominent frames—legitimation, responsibility and stereotype—in which individual responsibility was highlighted, while social responsibility was backgrounded. Individual responsibility and blaming were the dominant discourses in both newspapers. Further, stereotypes, weight stigma and the thin ideal discourse were mentioned in the news items. Framing analysis revealed that news items on obesity tended to shift health costs onto individuals rather than highlight the responsibility of the food and drink industries. The presence of stereotype frames was greater in China Daily than The Australian.

This research has taken the first step to study child-feeding practices of Indian mothers in relation to childhood obesity. It compares feeding practices of Indian mothers with children aged 1-5 years living in Australia and Mumbai. Mothers in the Australian sample were more likely to use 'positive' feeding practices hypothesized to promote healthy growth and weight status. However, mothers in both samples commonly used coercive feeding practices that potentially increase the risk of childhood obesity. These results will inform interventions designed to promote healthy weight status in this cultural group.

Overweight and obesity are two of the most important emerging public health issues in our time and regarded by the World Health Organisation [WHO] (1998) as a worldwide epidemic. The prevalence of obesity in the USA is the highest in the world, and Australian obesity rates fall into second place. Currently, about 60% of Australian adults are overweight (BMI „d 25kg/m2). The socio-demographic factors associated with overweight and/or obesity have been well demonstrated, but many of the existing studies only examined these relationships at one point of time, and did not examine whether significant relationships changed over time. Furthermore, only limited previous research has examined the issue of the relationship between perception of weight status and actual weight status, as well as factors that may impact on people¡¦s perception of their body weight status. Aims: The aims of the proposed research are to analyse the discrepancy between perceptions of weight status and actual weight status in Australian adults; to examine if there are trends in perceptions of weight status in adults between 1995 to 2004/5; and to propose a range of health promotion strategies and furth er research that may be useful in managing physical activity, healthy diet, and weight reduction. Hypotheses: Four alternate hypotheses are examined by the research: (1) there are associations between independent variables (e.g. socio -demographic factors, physical activity and dietary habits) and overweight and/or obesity; (2) there are associations between the same independent variables and the perception of overweight; (3) there are associations between the same independent variables and the discrepancy between weight status and perception of weight status; and (4) there are trends in overweight and/or obesity, perception of overweight, and the discrepancy in Australian adults from 1995 to 2004/5. Conceptual Framework and Methods: A conceptual framework is developed that shows the associations identified among socio -demographic factors, physical activity and dietary habits with actual weight status, as well as examining perception of weight status. The three latest National Health Survey data bases (1995 , 2001 and 2004/5) were used as the primary data sources. A total of 74,114 Australian adults aged 20 years and over were recruited from these databases. Descriptive statistics, bivariate analyses (One -Way ANOVA tests, unpaired t-tests and Pearson chi-square tests), and multinomial logistic regression modelling were used to analyse the data. Findings: This research reveals that gender, main language spoken at home, occupation status, household structure, private health insurance status, and exercise are related to the discrepancy between actual weight status and perception of weight status, but only gender and exercise are related to the discrepancy across the three time point s. The current research provides more knowledge about perception of weight status independently. Factors which affect perception of overweight are gender, age, language spoken at home, private health insurance status, and diet ary habits. The study also finds that many factors that impact overweight and/or obesity also have an effect on perception of overweight, such as age, language spoken at home, household structure, and exercise. However, some factors (i.e. private health insurance status and milk consumption) only impact on perception of overweight. Furthermore, factors that are rel ated to people’s overweight are not totally related to people’s underestimation of their body weight status in the study results. Thus, there are unknown factors which can affect people’s underestimation of their body weight status. Conclusions: Health promotion and education activities should provide education about population health education and promotion and education for particular at risk sub -groups. Further research should take the form of a longitudinal study design ed to examine the causal relationship between overweight and/or obesity and underestimation of body weight status, it should also place more attention on the relationships between overweight and/or obesity and dietary habits, with a more comprehensive representation of SES. Moreover, further research that deals with identification of characteristics about perception of weight status, in particular the underestimation of body weight status should be undertaken.

Overweight and obesity are two of the most important emerging public health issues in our time and regarded by the World Health Organisation [WHO] (1998) as a worldwide epidemic. The prevalence of obesity in the USA is the highest in the world, and Australian obesity rates fall into second place. Currently, about 60% of Australian adults are overweight (BMI „d 25kg/m2). The socio-demographic factors associated with overweight and/or obesity have been well demonstrated, but many of the existing studies only examined these relationships at one point of time, and did not examine whether significant relationships changed over time. Furthermore, only limited previous research has examined the issue of the relationship between perception of weight status and actual weight status, as well as factors that may impact on people¡¦s perception of their body weight status. Aims: The aims of the proposed research are to analyse the discrepancy between perceptions of weight status and actual weight status in Australian adults; to examine if there are trends in perceptions of weight status in adults between 1995 to 2004/5; and to propose a range of health promotion strategies and furth er research that may be useful in managing physical activity, healthy diet, and weight reduction. Hypotheses: Four alternate hypotheses are examined by the research: (1) there are associations between independent variables (e.g. socio -demographic factors, physical activity and dietary habits) and overweight and/or obesity; (2) there are associations between the same independent variables and the perception of overweight; (3) there are associations between the same independent variables and the discrepancy between weight status and perception of weight status; and (4) there are trends in overweight and/or obesity, perception of overweight, and the discrepancy in Australian adults from 1995 to 2004/5. Conceptual Framework and Methods: A conceptual framework is developed that shows the associations identified among socio -demographic factors, physical activity and dietary habits with actual weight status, as well as examining perception of weight status. The three latest National Health Survey data bases (1995 , 2001 and 2004/5) were used as the primary data sources. A total of 74,114 Australian adults aged 20 years and over were recruited from these databases. Descriptive statistics, bivariate analyses (One -Way ANOVA tests, unpaired t-tests and Pearson chi-square tests), and multinomial logistic regression modelling were used to analyse the data. Findings: This research reveals that gender, main language spoken at home, occupation status, household structure, private health insurance status, and exercise are related to the discrepancy between actual weight status and perception of weight status, but only gender and exercise are related to the discrepancy across the three time point s. The current research provides more knowledge about perception of weight status independently. Factors which affect perception of overweight are gender, age, language spoken at home, private health insurance status, and diet ary habits. The study also finds that many factors that impact overweight and/or obesity also have an effect on perception of overweight, such as age, language spoken at home, household structure, and exercise. However, some factors (i.e. private health insurance status and milk consumption) only impact on perception of overweight. Furthermore, factors that are rel ated to people’s overweight are not totally related to people’s underestimation of their body weight status in the study results. Thus, there are unknown factors which can affect people’s underestimation of their body weight status. Conclusions: Health promotion and education activities should provide education about population health education and promotion and education for particular at risk sub -groups. Further research should take the form of a longitudinal study design ed to examine the causal relationship between overweight and/or obesity and underestimation of body weight status, it should also place more attention on the relationships between overweight and/or obesity and dietary habits, with a more comprehensive representation of SES. Moreover, further research that deals with identification of characteristics about perception of weight status, in particular the underestimation of body weight status should be undertaken.

Increasing numbers of Australian children are being classified as overweight or obese. Given the health complications associated with excess weight, interventions to prevent children becoming overweight are crucial. Despite literature showing that parents shape their children’s food and exercise habits, no child obesity prevention programs have directly targeted parents. Moreover, although fear appeals have been used across several health promotion areas to change attitudes and behaviours, they have not been incorporated into an obesity preventive program. This study addressed these gaps by testing whether fear-based obesity simulations, targeted at parents as a tool for preventing childhood obesity, was more effective than an educational obesity message. The study was designed in two stages, with the first piloting the effectiveness of the simulations and an obesity message on a small sample of parents. Stage 2 tested a larger sample of parents and incorporated modifications from the pilot. In Stage 1, nine parents were randomly assigned to a Simulation or Education Presentation. Parents completed interviews and questionnaires at three different time points over a week. SPANOVAs revealed no significant improvements in attitudes, intentions, motivations, fears, and knowledge about obesity prevention for the Simulation compared to the Education Presentation. This contrasted to interview findings which indicated that parents found the Simulation Presentation more effective and changed their attitudes and behaviours compared to the Education Presentation. These findings highlighted important outcomes and informed the development of Stage 2. A qualitative approach was more effective in eliciting parental responses to their presentation; the education information may have been “too effective” and masked any impact of the simulations; and potential limitations regarding the insensitivity of the Likert scale, used to measure changes in parent responses to the questionnaire, may have mitigated any significant effects being found. The purpose of Stage 2 was to explore any impact of the simulations only through in depth parent interviews, and to use objective pedometer, food and anthropometric measures to triangulate and enhance the interview findings. Twenty four different parents were assigned to a photo or non-photo group. Parents and children completed interviews, anthropometric measurements, food records, and pedometer counts at three time points over eight weeks. Quantitative analyses found no significant improvements in children’s pedometer scores, food intake, and achievement of activity and diet recommendations, or in parent intention to change their children’s eating and exercise habits for the photo compared to the non-photo group. Many children failed to meet daily food and activity guidelines by the end of the study. This contrasts markedly to interview findings stating that: parents made improvements to their children’s diet and exercise patterns and, for parents who didn’t make changes, this was attributed to perceptions that they were already doing the right thing for their children. This disparity in results revealed an important yet underexplored issue for interventions targeting weight-related lifestyle changes. This focuses on levels of parental awareness about their children’s dietary adequacy and activity levels, and bridging the gap between what one perceives they are doing versus the reality of what is actually happening. This discrepancy may have mitigated any impact of the simulations through a false sense of adequacy and parent risk levels toward their children developing obesity.

This thesis presents new data on the risk of obesity among immigrants to Australia. The findings show that obesity prevention efforts need to include vulnerable ethnic groups, immigrants in the early-mid settlement period, and immigrant families arriving with children and adolescents. In addition, healthier environments are needed to support healthy weight; particularly in poorer neighbourhoods and areas outside Australia's cities.

Childhood and adolescent obesity is a significant problem in Australia and it has reached alarming levels. While most studies have suggested that increased levels of physical activity, combined with improved nutrition can improve body composition and health of children who are obese or overweight, the majority of these programs have used aerobic-based interventions. Despite the abundant research on the role of which parents and schools can play in the prevention of obesity in children, the use of resistance training in youth and health promotion is a fairly new concept, and one that needs further study.

This thesis undertakes an empirical investigation to identify factors that influence the decision to undertake weight loss behaviour using the nationally representative HILDA dataset. Although many factors influenced the decision, the findings suggested that body weight satisfaction was the greatest determinant of weight loss dieting. This thesis therefore conducted a further empirical study to analyse the determinants of body weight satisfaction. A rank-hypothesis was found to better predict variation in body weight satisfaction levels than the absolute value of the individual's Body Mass Index (BMI) or the relative-norm hypothesis, which are commonly reported in the literature.

Background and Objectives Obesity and some dietary related diseases are emerging health problems among Chinese immigrants and their children in developed countries. These health problems are closely linked to eating habits, which are established in the early years of life. Young children’s eating habits are likely to persist into later childhood and youth. Family environment and parental feeding practices have a strong effect on young children’s eating habits. Little information is available on the early feeding practices of Chinese mothers in Australia. The aim of this study was to understand the dietary beliefs, feeding attitudes and practices of Chinese mothers with young children who were recent immigrants to Australia. Methods Using a sequential explanatory design, this mixed methods study consisted of two distinct phases. Phase 1 (quantitative): 254 Chinese immigrant mothers of children aged 12 to 59 months completed a cross-sectional survey. The psychometric properties and factor structure of a Chinese version of the Child Feeding Questionnaire (CFQ, by Birch et al. 2001) were assessed and used to measure specific maternal feeding attitudes and controlling feeding practices. Other questions were developed from the literature and used to explore maternal traditional dietary beliefs and feeding practices related to their beliefs, perceptions of picky eating in children and a range of socioeconomic and acculturation factors. Phase 2 (qualitative): 21 mothers took part in a follow-up telephone interview to assist in explaining and interpreting some significant findings obtained in the first phase. Results Chinese mothers held strong traditional dietary beliefs and fed their children according to these beliefs. However, children’s consumption of non-core foods was high. Both traditional Chinese and Australian style foods were consumed by their children. Confirmatory factor analysis revealed that the original 7-factor model of the CFQ provided an acceptable fit to the data with minor modification. However, an alternative model with eight constructs in which two items related to using food rewards were separated from the original restriction construct, not only provided an acceptable fit to the data, but also improved the conceptual clarity of the constructs. The latter model included 24 items loading onto the following eight constructs: restriction, pressure to eat, monitoring, use of food rewards, perceived responsibility, perception of own weight, perception of child’s weight, and concern about child becoming overweight. The internal consistency of the constructs was acceptable or desirable (Cronbach’s α = .60 - .93). Mothers reported low levels of concern about their child overeating or becoming overweight, but high levels of controlling feeding practices: restriction, monitoring, pressure to eat and use of food rewards. More than one quarter of mothers misinterpreted their child’s weight status (based on mothers’ self-reported data). In addition, mothers’ controlling feeding practices independently predicted half of the variance and explained 16% of the variance in child weight status: pressuring the child to eat was negatively associated with child weight status (β = -0.30, p < .01) and using food rewards was positively associated with child weight status (β = 0.20, p < .05) after adjusting for maternal and child covariates. Monitoring and restriction were not associated with child weight status. Mothers’ perceptions of their child’s weight were positively associated with child weight status (β = 0.33, p < .01). Moreover, mothers reported that they mostly decided what (65%) and how much (80%) food their child ate. Mothers who decided what food their child ate were more likely to monitor (β = -0.17, p < .05) and restrict (β = -0.17, p < .05) their child’s food consumption. Mothers who let their child decide how much food their child ate were less likely to pressure their child to eat (β = -0.38, p < .01) and use food rewards (β = -0.24, p < .01). Mothers’ perceptions of picky eating behaviour were positively associated with their use of pressure (β = 0.21, p < .01) and negatively associated with monitoring (β = -0.16, p < .05) and perceptions of their child’s weight status (β = -0.13, p < .05). Qualitative data showed that pressuring to eat, monitoring and restriction of the child’s food consumption were common practices among these mothers. However, mothers stated that their motivation for monitoring and restricting was to ensure the child’s general health. Mothers’ understandings of picky eating behaviour in their children were consistent with the literature and they reported multiple feeding strategies to deal with it. Conclusion Chinese immigrant mothers demonstrated strong traditional dietary beliefs, a low level of concern for child weight, misperceptions of child weight status, and a high overall level of control in child feeding in this study. The Chinese version of the CFQ, which consists of eight constructs and distinguishes between the constructs using food rewards and restriction, is an appropriate instrument to assess feeding attitudes and controlling feeding practices among Chinese immigrant mothers of young children in Australia. Mothers’ feeding attitudes and practices were associated with children’s weight status and mothers’ perceptions of picky eating behaviour in children after adjusting for a range of socio-demographic maternal and child characteristics. Monitoring and restriction of children’s food consumption according to food selection may be positive feeding practices, whereas pressuring to eat and using food rewards appeared to be negative feeding practices in this study. In addition, the results suggest that these young children have high exposure to energy-dense, nutrient-poor food. There is a need to develop and implement nutrition interventions to improve maternal feeding practices and the dietary quality among children of Chinese immigrant mothers in Australia.

Childhood overweight and obesity is a significant and increasing health problem both nationally and globally. Yet few interventions for preventing obesity have been successful, particularly in the long-term, suggesting that important factors are being overlooked. The aims of this thesis were to investigate (a) the prevalence of childhood overweight, obesity, and binge eating; and (b) the relationships between body weight, binge eating behaviour, and a set of physical, psychological, and psychosocial variables including parent body size, body dissatisfaction, size-related teasing experiences, internalisation of sociocultural messages, depression, dieting attitudes and behaviour, and emotional eating. Participants were 569 grade five and six primary school children (272 boys and 297 girls) from Catholic and Government schools across metropolitan Melbourne, Australia. Almost 25% of participants were classified as overweight or obese. Thirteen percent of participants reported engaging in overeating (with or without loss of control), 14% reported loss of control (with or without overeating), and 6% reported engaging in binge eating (overeating and loss of control). Structural equation modelling analyses found that body weight and binge eating were indirectly related. Body weight was directly and positively associated with parent body size, size-related teasing experiences, body dissatisfaction, and internalisation of sociocultural messages, negatively associated with emotional eating, and indirectly associated with depression, and dieting attitudes and behaviour. Binge eating was directly and positively related to parent body size, emotional eating, depression, and body dissatisfaction, while indirect associations were found with size-related teasing experiences, internalisation of sociocultural messages, and dieting attitudes and behaviour. A direct relationship between body dissatisfaction and loss of control was also found. Some gender differences were detected. Multivariate analysis of variance also revealed that binge eaters scored significantly higher on measures of depression, size-related teasing experiences, internalisation of sociocultural messages, and angry and worried related emotional eating than non-binge eaters. Differences were also found for participants reporting the presence or absence of overeating (regardless of loss of control) and loss of control (regardless of overeating). Overall, the study demonstrated that psychological and psychosocial factors have a significant association with both weight and binge eating behaviour in a non-clinical sample of preadolescent Australian school children. As such, future intervention programs may benefit by addressing these factors. In addition, these results support the idea of working toward the prevention of obesity and eating disorders simultaneously in children, and of extending research in this area to examine causality.

Thesis (PhD) - Faculty of Life and Social Sciences, Swinburne University of Technology, 2006.
Submitted in partial fulfillment of the requirements for the degree of Professional Doctorate of Psychology (Health Physiology), Faculty of Life and Social Sciences, Swinburne University of Technology - 2006. Typescript. Includes bibliographical references (p. 144-164).

[Truncated abstract] Obesity is now a major public health problem worldwide. More than half the Australian population is now overweight. This is an important public health concern primarily because of the impact of overweight and obesity on risk of diabetes, hypertension and cardiovascular disease. Many strategies have been proposed to fight the obesity epidemic. One possible strategy involves understanding of the role of dietary components in the control of food intake. In this regard, dietary protein and fibre appear to be the most satiating nutrients. Foods enriched in protein, replacing energy from carbohydrate, or dietary fibre can increase satiety and reduce energy intake in the short-term. Longer-term trials suggest benefits of increasing protein or fibre intake on weight loss and features of the metabolic syndrome. The effects of dietary approaches which increase both protein and fibre at the expense of refined carbohydrate are uncertain. A practical approach to increasing both protein and fibre content of processed foods is to incorporate high protein and fibre ingredients into high carbohydrate foods. Lupin kernel flour is a novel food ingredient derived from the endosperm of lupin. It contains 40 to 45% protein, 25 to 30% fibre, and negligible sugar and starch. Lupin kernel flour can be incorporated into refined carbohydrate rich foods such as bread to increase protein and fibre content at the expense of refined carbohydrate. ... Body weight was measured every 2 weeks throughout the 16 week intervention, and these data were analysed to determine whether there was any between group difference in the rate of change in weight over 16 weeks. Over 16 weeks, lupin bread compared to white bread resulted in a significant increase in protein (13.7 (2.3, 25.0) g/d) and fibre (12.5 (8.8, 16.2) g/d) intakes, and a decrease in carbohydrate intake (-19.9 (-45.2, 5.5) g/d). There was a significant difference between groups in the rate of weight change over the 16 weeks (P=0.05). However, at 16 weeks there was no significant effect on body weight (-0.4 (-1.3, 0.6) kg), fat mass (-0.5 (-1.2, 0.2) kg) or fat free mass (0.2 (-0.5, 0.8) kg). Plasma adiponectin and leptin were not altered. Mean 24 hour systolic blood pressure (-2.4 (-3.4, -1.3) mm Hg) and pulse pressure (-3.1 (-3.9, -2.3) mm Hg) were lower for lupin relative to white bread, but diastolic blood pressure was not significantly different between groups. Apart from a lower HDL cholesterol for lupin relative to white bread (-0.09 (-0.17, -0.01) mmol/L), there were no significant differences in other blood lipids and glucose and insulin concentrations. Interpretation of the results was not influenced after adjustment for potential confounding factors. These studies assessed effects of bread enriched in lupin kernel flour relative to white bread, resulting in a higher protein and fibre intake and lower refined carbohydrate intake. This increased satiety and reduced energy intake acutely, but did not significantly influence body weight over 16 weeks. Systolic blood pressure and pulse pressure were significantly reduced. There were no significant improvements in blood lipids or glucose and insulin concentrations. Therefore, increasing protein and fibre intake at the expense of refined carbohydrate using lupin kernel flour may benefit satiety and blood pressure. Longer-term trials incorporating weight loss may be needed to observe benefits on body weight.

The increasing prevalence of overweight and obesity in young people is a major global public health concern, especially in developed countries. In Australia, studies in 2001 have suggested that 20% of boys and 21.5% of girls aged 7-15 years were overweight or obese, while in 1985 the figures were 10.7% and 11.8%, respectively. In the short-term, overweight and obese children and adolescents suffer from both adverse physical and psychological consequences. The most significant long-term consequence of childhood obesity is its persistence into adulthood, along with numerous associated health risks. A number of studies have shown that there is an association between being an overweight child and subsequent adulthood obesity. In general, childhood overweight and obesity is a multifactorial disease and its development is due to multiple interactions between genes and environment. A number of risk factors such as socioeconomic status, dietary patterns, and physical activity have been frequently identified as contributors to its development. However, the results of recent studies provide conflicting evidence. The statistical limitations also make it difficult to compare the studies on childhood obesity between countries. In addition, existing research in Australia that examines the contribution of different risk factors to childhood obesity is limited. There are no published data on the relationship between overweight/obesity, dietary patterns, and physical activity/inactivity in Australian children and adolescents. This study examined the influences of household income, dietary factors, physical activity/inactivity and ethnicity on overweight and obesity among Australian children and adolescents. It also explored the relationship between self-reported weight and height to actual weight and height in older Australian adolescents in order to clarify the accuracy of self-reported data among Australian youth. Data from the two national cross-sectional surveys, the 1995 Australian National Health Survey (NHS) and the 1995 National Nutrition Survey (NNS) were analysed to explore the influences of household income, intake of energy and fat and percentage of energy from fat on childhood obesity. The study focused on 1585 children and adolescents aged 7-15 years. These data were also used to examine the relationship of self-reported weight and height to measured weight and height in older adolescents. Additionally, another cross-sectional survey among a group of Australian primary school children from a multi-cultural school in southern Brisbane was undertaken as well as providing indicative data on the relationship of overweight/obesity to physical activity levels and ethnicity, and to provide a protocol on the methodology and practicality of measuring physical activity level in such a school setting. The results suggested that boys from households with low incomes were more likely to be overweight or obese compared with those from households with higher incomes. Having parents, especially mothers, who were overweight or obese increased the risk of children being overweight or obese. The results do not provide evidence that there are statistically significantly differences in the average intake of energy and fat and percentage of energy from fat between non-overweight and overweight or obese boys and girls. The correct classification of weight or obesity from self-reported height and weight by Australian older adolescents was about 70%, bias in reporting weight and height is higher among overweight or obese older adolescents than non-overweight counterparts. In addition, preliminary, indicative data from the pilot study on the relationship between body mass index (BMI) and physical activity in 10-12 year old Australian school children from a multi-cultural school revealed that the average daily physical activity level (PAL) was 2.3 Metabolic Equivalents (METs) when the PAL was measured using self-reported activity diary. The proportion of light, moderate and heavy PAL was 2.9%, 20.4% and 76.7% in children, respectively. Additionally no ethnic differences in the prevalence of overweight /obesity was found. There was no statistically significant difference in average daily TV view times between non-overweight and overweight or obese boys and girls. The average daily number of steps measured using pedometer in the weekdays was 16,505 in boys and 12766 in girls. Most of boys (94.0%) have a medium and over level of steps taken daily while nearly one-third of the girls had not reached the minimum level in the number of steps for optimal health. However it must be noted this school-based study was a small cross-sectional survey in a single school. The results should be viewed as indicative, not generalisable. The study does not provide any longitudinal data on physical activity patterns and the trends in relationship to body mass index. In spite of the limitations of this study, it did provide some preliminary data on PAL and its relationship to overweight/ obesity among young Australian schoolchildren from diverse cultural backgrounds. Most importantly, this pilot study has provided a protocol on the methodology and practicality of measuring physical activity levels of children using self-reported activity diaries and pedometers in a multicultural school setting. A number of strategies for the prevention and treatment of childhood overweight and obesity are discussed. In future studies, a population-based and randomly selected sample would ensure findings that are more representative of general Australian children, and the longitudinal studies would help to define the association between the risk factors and childhood obesity, as well as enabling conclusions on causality to be drawn.

The increasing prevalence of overweight and obesity in young people is a major global public health concern, especially in developed countries. In Australia, studies in 2001 have suggested that 20% of boys and 21.5% of girls aged 7-15 years were overweight or obese, while in 1985 the figures were 10.7% and 11.8%, respectively. In the short-term, overweight and obese children and adolescents suffer from both adverse physical and psychological consequences. The most significant long-term consequence of childhood obesity is its persistence into adulthood, along with numerous associated health risks. A number of studies have shown that there is an association between being an overweight child and subsequent adulthood obesity. In general, childhood overweight and obesity is a multifactorial disease and its development is due to multiple interactions between genes and environment. A number of risk factors such as socioeconomic status, dietary patterns, and physical activity have been frequently identified as contributors to its development. However, the results of recent studies provide conflicting evidence. The statistical limitations also make it difficult to compare the studies on childhood obesity between countries. In addition, existing research in Australia that examines the contribution of different risk factors to childhood obesity is limited. There are no published data on the relationship between overweight/obesity, dietary patterns, and physical activity/inactivity in Australian children and adolescents. This study examined the influences of household income, dietary factors, physical activity/inactivity and ethnicity on overweight and obesity among Australian children and adolescents. It also explored the relationship between self-reported weight and height to actual weight and height in older Australian adolescents in order to clarify the accuracy of self-reported data among Australian youth. Data from the two national cross-sectional surveys, the 1995 Australian National Health Survey (NHS) and the 1995 National Nutrition Survey (NNS) were analysed to explore the influences of household income, intake of energy and fat and percentage of energy from fat on childhood obesity. The study focused on 1585 children and adolescents aged 7-15 years. These data were also used to examine the relationship of self-reported weight and height to measured weight and height in older adolescents. Additionally, another cross-sectional survey among a group of Australian primary school children from a multi-cultural school in southern Brisbane was undertaken as well as providing indicative data on the relationship of overweight/obesity to physical activity levels and ethnicity, and to provide a protocol on the methodology and practicality of measuring physical activity level in such a school setting. The results suggested that boys from households with low incomes were more likely to be overweight or obese compared with those from households with higher incomes. Having parents, especially mothers, who were overweight or obese increased the risk of children being overweight or obese. The results do not provide evidence that there are statistically significantly differences in the average intake of energy and fat and percentage of energy from fat between non-overweight and overweight or obese boys and girls. The correct classification of weight or obesity from self-reported height and weight by Australian older adolescents was about 70%, bias in reporting weight and height is higher among overweight or obese older adolescents than non-overweight counterparts. In addition, preliminary, indicative data from the pilot study on the relationship between body mass index (BMI) and physical activity in 10-12 year old Australian school children from a multi-cultural school revealed that the average daily physical activity level (PAL) was 2.3 Metabolic Equivalents (METs) when the PAL was measured using self-reported activity diary. The proportion of light, moderate and heavy PAL was 2.9%, 20.4% and 76.7% in children, respectively. Additionally no ethnic differences in the prevalence of overweight /obesity was found. There was no statistically significant difference in average daily TV view times between non-overweight and overweight or obese boys and girls. The average daily number of steps measured using pedometer in the weekdays was 16,505 in boys and 12766 in girls. Most of boys (94.0%) have a medium and over level of steps taken daily while nearly one-third of the girls had not reached the minimum level in the number of steps for optimal health. However it must be noted this school-based study was a small cross-sectional survey in a single school. The results should be viewed as indicative, not generalisable. The study does not provide any longitudinal data on physical activity patterns and the trends in relationship to body mass index. In spite of the limitations of this study, it did provide some preliminary data on PAL and its relationship to overweight/ obesity among young Australian schoolchildren from diverse cultural backgrounds. Most importantly, this pilot study has provided a protocol on the methodology and practicality of measuring physical activity levels of children using self-reported activity diaries and pedometers in a multicultural school setting. A number of strategies for the prevention and treatment of childhood overweight and obesity are discussed. In future studies, a population-based and randomly selected sample would ensure findings that are more representative of general Australian children, and the longitudinal studies would help to define the association between the risk factors and childhood obesity, as well as enabling conclusions on causality to be drawn.

This thesis explored the suitability of health-oriented, size-accepting approaches for use in Australian dietetics counselling with weight-concerned adults. Across three studies, this work established that such an approach has an acceptable evidence base to drive Australian dietetics practice and may be a superior method to support higher dietary quality and lower eating disorder risk when compared with weight-centric approaches.

The purpose of this study was to understand the factors that encourage midlife women to make exercise and dietary changes, the prevalence of those changes, the process by which women make them, the factors that support or impede them, and how we can enhance women’s capacity to make health behaviour changes in midlife. Since the literature highlighted the importance of self-efficacy in changing health behaviour, and of health-related quality of life as a widely recognized measure of women’s mental and physical wellbeing, the study sought to understand the relationship between exercise and dietary self-efficacy, health behaviour change and health-related quality of life (SF-36), by testing a modified version of Bandura’s 1977 and 2002/2004b models of self-efficacy. The methodology involved postal surveys as well as semi-structured interviews with a subsample of the women who completed the survey. Surveys were sent to 866 women aged 51-66 years from rural and urban locations in Queensland, Australia. Five hundred and sixty-four (69%) were completed and returned. Survey data was analysed using descriptive and bivariate statistics and structural equation modeling. Thematic analysis was used to analyse interviews. The results confirmed that midlife is a significant time for women to make positive health behaviour changes. Almost 40% of women made a change to their exercise and around 60% made a dietary change since turning 40. The main exercise change was doing more walking and the most common dietary change was reducing fat intake. Self-efficacy was shown to be a key influence on whether women made positive changes to their health in midlife. In the relationship between health behaviour change and health-related quality of life, making a positive change to exercise was significantly related to physical but not mental health, and making a dietary change was not related to either physical or mental health. Body mass index was shown to be an important influence on both self-efficacy and health-related quality of life (particularly physical health). Interviews were conducted with 29 of the participants. Interview data reinforced that the main motivations to make a positive health behaviour change among midlife women were being overweight, having an injury or being diagnosed with an illness or health condition. Witnessing the hardship experienced by others with a degenerative disease could also prompt a positive behaviour change. Successful changes mainly involved modifying existing practices and repeating new behaviours until they became part of the daily routine. The main facilitators of health behaviour change were having positive role models, having more time due to retirement, and having support from significant others (such as husbands), health professionals and organizations such as Weight Watchers. The main obstacles to making changes were work, care giving, illness and injury. Bandura’s (1977, 2000/2004b) model was partially supported, but the cross-sectional nature of the study may have been a limitation in demonstrating all aspects of the self-efficacy process. In summary, women are willing to make positive health behaviour changes in midlife, but they need education and support to have those changes be effective. It is anticipated that this research will lead to a greater understanding of the significance of midlife as a time for making healthy lifestyle changes that have the potential to improve women’s health and quality of life in later years.

The purpose of this study was to understand the factors that encourage midlife women to make exercise and dietary changes, the prevalence of those changes, the process by which women make them, the factors that support or impede them, and how we can enhance women’s capacity to make health behaviour changes in midlife. Since the literature highlighted the importance of self-efficacy in changing health behaviour, and of health-related quality of life as a widely recognized measure of women’s mental and physical wellbeing, the study sought to understand the relationship between exercise and dietary self-efficacy, health behaviour change and health-related quality of life (SF-36), by testing a modified version of Bandura’s 1977 and 2002/2004b models of self-efficacy. The methodology involved postal surveys as well as semi-structured interviews with a subsample of the women who completed the survey. Surveys were sent to 866 women aged 51-66 years from rural and urban locations in Queensland, Australia. Five hundred and sixty-four (69%) were completed and returned. Survey data was analysed using descriptive and bivariate statistics and structural equation modeling. Thematic analysis was used to analyse interviews. The results confirmed that midlife is a significant time for women to make positive health behaviour changes. Almost 40% of women made a change to their exercise and around 60% made a dietary change since turning 40. The main exercise change was doing more walking and the most common dietary change was reducing fat intake. Self-efficacy was shown to be a key influence on whether women made positive changes to their health in midlife. In the relationship between health behaviour change and health-related quality of life, making a positive change to exercise was significantly related to physical but not mental health, and making a dietary change was not related to either physical or mental health. Body mass index was shown to be an important influence on both self-efficacy and health-related quality of life (particularly physical health). Interviews were conducted with 29 of the participants. Interview data reinforced that the main motivations to make a positive health behaviour change among midlife women were being overweight, having an injury or being diagnosed with an illness or health condition. Witnessing the hardship experienced by others with a degenerative disease could also prompt a positive behaviour change. Successful changes mainly involved modifying existing practices and repeating new behaviours until they became part of the daily routine. The main facilitators of health behaviour change were having positive role models, having more time due to retirement, and having support from significant others (such as husbands), health professionals and organizations such as Weight Watchers. The main obstacles to making changes were work, care giving, illness and injury. Bandura’s (1977, 2000/2004b) model was partially supported, but the cross-sectional nature of the study may have been a limitation in demonstrating all aspects of the self-efficacy process. In summary, women are willing to make positive health behaviour changes in midlife, but they need education and support to have those changes be effective. It is anticipated that this research will lead to a greater understanding of the significance of midlife as a time for making healthy lifestyle changes that have the potential to improve women’s health and quality of life in later years.

It is now widely accepted that political actors think and talk about matters of common interest through narratives. But there has been relatively little attention on the consequences of this phenomenon for deliberative conceptions of democracy. On one hand, many of the qualities associated with narrative would tend to suggest it is a pathology of deliberation: in this sense, narrative might be seen as sensationalising and polarising issues, and manipulating and ultimately corrupting rational consideration of the facts. On the other hand, other qualities would suggest that narrative could be a key resource for deliberation: it can also be seen as facilitating communication between diverse actors and mobilising opinion on intractable issues, thereby legitimating political decisions and decision-making processes. This thesis probes these apparently contradictory understandings of narrative by asking: what impact does narrative have on public deliberation? It examines this impact, understood in terms of narrative's influence on deliberative practice, both empirically and normatively. It seeks to determine how narrative influences public deliberation on a complex and contested issue and to interpret what these impacts mean for deliberative democratic ideals. The research explores this question through a comparative case study of public deliberation on the issue of obesity in Australia and the UK. In line with recent developments in deliberative democratic theory, the research adopts a 'deliberative systems' approach to public deliberation on obesity, on the basis that democratic deliberation does and should take place across a range of differentiated but interconnected sites of discussion. As such, it examines the interplay between narratives in various sites of public deliberation on the issue of obesity in Australia and the UK between 2007 and 2011. This study explores how political actors think and talk about obesity as a policy problem through a narrative analysis - a method firmly lodged in the interpretive tradition, in that its focus is on the meanings that political actors ascribe to events. The research, drawing on extensive textual data and over 35 semi-structured interviews with relevant policy actors, identifies the different narratives that actors engaged in policy debate on obesity adhere to and assesses how and to what effect they are performed across sites. The findings challenge prevailing assumptions about the role of narrative in public deliberation. They indicate that the different narratives on obesity do not simply polarize or sensationalise deliberation, nor do they unproblematically facilitate it. Instead, the research produces a rich analysis which shows how the narratives on obesity collectively work to blunt the force of critical or urgent voices, orchestrate and mask conflict on key aspects of the issue, and fudge the detail of specific claims, especially in or near decision-making sites of deliberation. It documents how this discursive process constructs 'wiggle room' around the issue which is more easily exploited by powerful and well-resourced actors, albeit more acutely in Australia than in the UK. The project concludes by exploring this comparative difference to suggest ways in which such deliberative systems might be strengthened. Overall, this research makes crucial methodological, empirical and conceptual advances to scholarship on narrative in politics and policymaking, as well as providing salient lessons for general policy scholars and public health scholars, too. Its ultimate contribution, though, is to the broader effort to understand and improve public deliberation on complex and contested issues in theory and in practice.

Over the last 40 years Australia has experienced a growing prevalence of obesity. This trend carries with it an expectation that associated burdens of disease and health care costs will be incurred. Thus far, the dominant response to the growth in obesity has been to focus on individuals' personal responsibility to resist weight gain. This approach assumes that all individuals have the capacity to incorporate knowledge about health into their lives and make appropriate behavioural changes. An alternative explanation is the obesogenic environment theory, which positions individual choices within the constraints of their physical, social, cultural and political environment. It has been adopted by many public health experts but has had limited influence on personal and policy responses to obesity. This thesis assesses whether the healthy citizenship approach to obesity can be effective in an obesogenic environment by exploring life narrative interviews with 60 related Australians from three generations. Firstly, it examines the emergence over the 20th century of diet and exercise as key 'technologies of the self' for shaping a healthy self and healthy weight in order to conform to norms of healthy citizenship. Secondly, it demonstrates how at the same time major social changes have dramatically reshaped diet and physical activity patterns in Australia. The narratives of the three generations are contextualised within Australian social history literature concerning three time periods - the Great Depression and World War Two (WWII), post-WWII decades, and the turn of the 21st century. This thesis illustrates how by the 1990s Australians were feeling the effects of an obesogenic environment in which food was readily available, life had become increasingly sedentary and maintaining an energy balance required effort. This sharply contrasted to life in the earlier to mid-20th century. Although I show that individuals subscribe to the norms of healthy citizenship, the obesogenic environment presents obstacles to successful conformity. All participants strived to conform and felt that they were doing the best they could within the context of their lives, but generally felt there was more they could do. Having a level of control to negotiate healthy choices was essential for resisting the obesogenic environment. However, not all participants had the cultural, economic or social resources to make these 'choices'. Additionally, the focus on weight as signifying conformity to healthy citizenship is problematic as practices undertaken to create a socially desirable body did not always align with those required to be healthy, and in some cases may even be detrimental to health. This thesis illustrates how the current healthy citizenship approach to preventing and managing obesity is limited by the constraints of the obesogenic environment and by the level of control individuals have over shaping their health. Although individuals are ultimately responsible for their own diet and physical activity, citizens must be enabled to make healthy choices. Hence, in order to shape a successful response to rising obesity rates governments, industry, communities and individuals need to work together to create an environment that fosters healthy, rather than unhealthy, choices.

Research Doctorate - Doctor of Philosophy (PhD)
Despite having some of the highest figures in the world in relation to obesity-related disease and premature death from preventable illnesses, Polynesians are not responding to Western biomedical suggestions for lifestyle interventions. The reasons behind this apparent reluctance are extensively explored in this thesis. Although there is a focus on health, in particular, obesity in this population group, this thesis also highlights the interaction between class and culture in all aspects of people’s lives. The challenge of maintaining consocial family values, identity and cultural practices in a new country and how these are adapting and changing is discussed, as well as issues around education, work practices and gender roles. This thesis, therefore, gives an overview of socio-economic and cultural issues affecting the growing Polynesian migrant community in Australia. This work has application for health professionals, policy makers, teachers, academics and community workers.

Obesity in children has increased rapidly in Western countries over the past three decades. Childhood obesity is a major public health issue because it contributes to immediate health and psychosocial problems in children, as well as increased risk of adult obesity and associated chronic disease, and restricted life opportunities. Obesity represents an inequality in health as, in Western countries, it is now most common in the most disadvantaged groups. However, it is not clear how the prevalence of childhood obesity has come to be socially patterned. A relatively small body of literature provides theoretical insights as to what might be occurring in families of low socio-economic status (SES) to increase the likelihood of childhood obesity. From recurrent organising explanations, three were selected for investigation: food-related parenting beliefs and practices; parental work patterns; and gender roles within families. Each of these domains is shaped by broader ideologies and structural arrangements. Briefly, it is argued that contemporary parenting beliefs and practices may lead parents to oblige children’s food requests, even when not in the child’s nutritional interests. Furthermore, parents may lack the ability to negotiate with children around food or to be firm when denying requests for unhealthy food. These parenting beliefs and practices may be most common in low SES families. Secondly, in contemporary society it is common for both parents to work, sometimes by choice, but often simply to achieve a reasonable standard of living. Work hours and the demands of work have increased over recent decades, contributing to time pressure for parents which in turn may compromise the family food environment. This could be most common in low SES families, lacking resources to alleviate time pressure in other ways. Thirdly, despite women now occupying a wider range of roles in society, gender stereotyping persists. In families, this means that women are responsible for food provisioning and childrearing, regardless of other demands on their time. This may be more common in low SES families than in other families, potentially contributing to SES differentials in childhood obesity. A cross-sectional study was undertaken within an existing birth cohort, when children were 9-10 years old, to investigate the extent to which the three aspects of family life were associated with obesity and overweight in children and whether this contributed to the social patterning of childhood overweight/obesity. Families in the sample were recruited during the mother’s pregnancy. Between 1998 and 2000, pregnant women were recruited from one public hospital and three private obstetric practices located in Adelaide. Mothers who agreed to participate in the 9-10 year interviews were invited to complete a structured personal interview, as well as several self-complete questionnaires. Children were invited to have their height and weight assessed, from which body mass index (BMI) was derived. Families who participated in the interviews are predominately Caucasian but otherwise broadly representative of the state population. Results presented in this thesis are based on the first 300 interviews completed. Maternal educational attainment at the time of the 9-10 year interview was selected as the indicator of SES (with categories of incomplete high school, high school completed, Technical and Further Education (TAFE) qualification, and university degree). In the study sample, 16 percent of children were overweight and a further 4 percent were obese at 9-10 years. Maternal educational attainment at this time point was the only family characteristic clearly associated with the combined outcome of childhood overweight/obesity. However, there was not a strict gradient in this relationship. Instead, childhood overweight/obesity was most prevalent in families in which the mother had gained a TAFE qualification. This may reflect the diverse nature of TAFE qualifications and the fact that around half of the women in this category had not completed high school. A set of 10 self-complete items was developed to characterise relevant parenting beliefs and practices. When considered separately, only the belief that children have unalterable food preferences was associated with child weight status: mothers who held this belief were less likely than other mothers to have overweight/obese children. When the beliefs and practices were amalgamated using factor analysis to form subscales reflecting Obliging, Influence and Firmness, the obliging score were associated with child weight status: more obliging mothers were less likely to have overweight/obese children. However, there was limited evidence for differences in Obliging, Influence and Firmness scores for mothers in different SES groups. On balance, it seems most likely that these findings reflect changes in food-related parenting beliefs and practices subsequent to children becoming overweight or obese. This underscores the need for longitudinal research in this domain. Two parent families were the focus of analyses concerning parental work arrangements. In particular, the circumstances in which parents frequently worked family-unfriendly work schedules (at night, after 6pm weekdays or on weekends) was investigated. Attention to fathers’ employment patterns is a relatively novel aspect of this research. The strongest research finding in this thesis was that when the partner of the study mother worked family-unfriendly schedules, children were most likely to be overweight or obese. While this did not appear to explain the higher prevalence of overweight/obesity in the lowest SES group, it was relevant to childhood overweight/obesity in families where the mother held a TAFE qualification. Additionally, almost half of children in families where both parents worked family-unfriendly work schedules were overweight or obese, although this was a minority of families. Mothers who reported poorer work-life balance (characterised using the Work-life Interference sub-index of the Australian Work And Life Index) were (marginally) more likely to have an overweight or obese child; this appeared to be most relevant to families in the highest SES group. Arguably, structural solutions are needed to address parents’ problematic work schedules and work-life balance. There is a role for government, employers, employees and wider society in rectifying these aspects of current work environments. The division of responsibilities in families and attitudes towards gender roles was analysed for two parent families. The sharing of domestic tasks was significantly associated with child weight status: where fathers did much less than their fair share children were most likely to be overweight/obese. There was evidence that this contributed to childhood overweight/obesity specifically in families where mothers held a TAFE qualification. A similar trend (not statistically significant) was observed for sharing of childrearing tasks. There was some indication that where partners were strongly encouraging or strongly disciplining around child food choices and eating behaviours, children were less likely to be overweight or obese. Overall, the extent to which mothers endorsed traditional gender stereotypes or supported transcending stereotypes was measured using the Social Roles Questionnaire. Analyses showed that mother’s gender role beliefs were not significantly associated with childhood overweight/obesity. However, mothers with the highest SES did not endorse traditional gender stereotypes to the same extent as other mothers and there was some indication that this reduced the likelihood of childhood overweight/obesity. Addressing the imbalance in parents’ responsibilities and roles would reduce the ‘double-shift’ undertaken by mothers and, potentially, its impact on childhood overweight/obesity. Challenging the policies and structures (such as the gender-pay gap) that reinforce traditional gender stereotypes for mothers and fathers is difficult, but would be necessary to achieve change on a broad scale. The findings of the thesis do not provide major insights about the excess of childhood obesity in the most disadvantaged families in society. Nevertheless, they point to potential benefits for all families of family friendly work schedules, satisfactory work-life balance and improved gender equity in fulfilling family responsibilities. Public health advocacy and initiatives around these matters is warranted for many reasons, not least the health of the children.
Thesis (Ph.D.) -- University of Adelaide, School of Population Health, 2013

Obesity is a worldwide problem, and as such a large body of research has focused on potential treatments to decrease excess body weight and the associated loss of adequate metabolic health. Obesity risk is influenced by more sedentary lifestyles, higher energy intakes and greater consumption of convenience and processed foods. Worldwide evidence indicates that these factors occur as part of nutrition transitions, typified by an increase in energy density and plant derived fats, refined carbohydrates and a reduction in the variety of food consumed. It is believed that this increase in availability of particular plant derived fats can influence health, with the monounsaturated fatty acid (MUFA) oleic acid (OA) appearing to preserve metabolic health, and the polyunsaturated fatty acid (PUFA), linoleic acid (LA), having potential negative impacts, though this has not been fully explored. The first study of this thesis aimed to investigate changes in the Australian diet from historically available population level food disappearance data and how the availability of common dietary fats, specifically OA and LA changed, and what foods have influenced this. This study found that over the time period 1961-2009 total available energy (TAE) from lipids increased 16.67 %, with a slight reduction in TAE from carbohydrates. Cumulative change in TAE from LA was +120.48 %, found to result from total plant oils having a + 627.19 % cumulative change in LA availability. As the effect of these fatty acids (FA) on weight gain and metabolic health is yet to be fully elucidated, a rodent study was performed, with 60 Sprague Dawley rats being fed a high fat ‘Western’ style diet to induce obesity for 9 weeks. The animals were then switched to diets with varying FA compositions, namely a standard ‘Western’ style diet, a high OA ‘Mediterranean’ style diet and a high LA diet for 6 weeks. The impact of these diets on body weight and composition, energy intake, glucose handling and adipose tissue and skeletal muscle metabolism was also investigated. As adiponectin is an insulin sensitising adipokine the ability of this to interact with FA and influence gene expression relating to FA metabolism in skeletal muscle was also investigated through incubation of excised muscles in physiological levels of globular adiponectin. 6 weeks of specific high fat diet feeding in male Sprague Dawley rats resulted in no significant differences between body weights, food intake, blood pressure, percentage body fat, or adipose depot specific change to FA metabolism genes for the 3 high fat fed groups. Despite this, this study does show that there is a potential for the type of dietary fat to modulate food intake and energy efficiency (week 6 high OA vs. high LA, 0.020 ± 0.005 and 0.037 ± 0.003, g gain/mJ, p=0.033), with reductions in both of these occurring for the high OA consuming animals towards the end of the study. Additionally, investigation of changes to gene expression in the muscles from these animals found the ability of adiponectin incubation to increase FAT/CD36, β-HAD and CPT1 mRNA expression in both the EDL and soleus from high OA fed animals (all p≤ 0.05 compared to tissue incubated without adiponectin), a response which was not seen in any of the other diet groups. This may indicate that high OA feeding preserves adiponectin sensitivity in both of these muscle types and may confer metabolic benefits not seen in the other high fat diets tested here. Finally, the ability of different FA to modulate acute appetite and hormonal responses following consumption of isoenergetic breakfasts containing elevated contents of carbohydrate, OA and LA respectively, was investigated in eight overweight and obese individuals (age 45.8 ± 3.6 years, BMI 32.0 ± 1.3 kg/m2 ) in a 3-way crossover single-blinded study. Consumption of all meals resulted in a significant increase in fullness and a reduction in desire to eat, with the control and high OA meals decreasing prospective food intake (p= 0.006 and p= 0.049 respectively), though this did not occur following ingestion of the high LA meal (p= 0.183). Additionally, following the consumption of the LA meal there was a significant increase in ghrelin production (compared to the control meal, p= 0.018). This was coupled with a spike in resistin production at the one hour time point, indicating potential impairment of insulin signalling. Taken together this indicates that high LA meals may promote excess energy intake and impair glucose handling, though further investigation is required. The results of this thesis indicate that LA availability in Australia has increased over the preceding 5 decades as a result of increased plant oil availabilities, as has total fat, possibly contributing to the increasing rates of obesity and obesity associated co-morbidities. Results from the animal and human studies indicate that a higher OA intake as opposed to LA may help to preserve skeletal muscle FA metabolism and potentially limit food intake, indicated by the reduction in food intake and energy efficiency seen in the high OA diet consuming rats in the rodent study and the increase in the appetite and food intake stimulating hormone ghrelin following consumption of the high LA meal in the human study.

University of Technology Sydney. Faculty of Arts and Social Sciences.
Since the 1990s, the issue of advertising to children, especially the role of food advertising and childhood obesity, has been the subject of much debate. Advertising to tweens in the US has been well studied; however, research into Australian food marketing has yet to examine its significance for the vulnerable tweenage viewer. The Australian ‘tweenage’ market (children aged 6 to 12) consists of $10 billion in spending each year in the Australian economy, yet very little is known about the Australian tweenage market. To examine the techniques and tactics advertisers use to market food products to tweens through Australian free-to air television, branded websites and Facebook pages, a mixed- methods approach was employed, combining content analysis, semiotic analysis and narrative literature review. Building on the work of Williamson (1978a), semiotic analysis was used to investigate the advertisements’ ideological underpinnings. Chapters 4 to 7 demonstrate that food advertisements broadcast during C-classified time describe the taste of the advertised food products in terms of freshness; they promote the advertised products as healthy on the basis of their weight management, energy giving and mood-enhancement properties; they use humour-, fantasy- and happiness-related themes to bestow a particular brand identity, image or personality on the products; and they employed humour and fantasy as vehicles for evoking happiness. Content analysis of the selected internet pages revealed that food company websites and Facebook pages promoted during children’s television programming contain advertisements, contests, social networking activities and membership benefits but, in order to engage in such activities, children have to register online as members by entering their names, addresses, ages, email addresses and other personal information into the companies’ online data gathering processes. The research uses narrative literature review to examine the responses of the industry’s self-regulation system to the changing media environment. This study found that the government, public health organisations and the food industry responded to rapid changes within the advertising, marketing and media industries by formulating, evaluating and amending advertising codes. This analysis concluded by demonstrating that the industry self-regulatory system has been unsuccessful in protecting children from exposure to unhealthy food advertising. Drawing upon the discoveries made during these investigations, conclusions and recommendations are presented, highlighting the need for a fresh approach to regulation and enforcement to protect tweens from the likely impacts of food and beverage advertising.

Background: Childhood obesity is a global phenomenon and public health problem. It is a chronic health condition associated with a body composition of excessive fat impacting on a child’s physical and social development. Public health initiatives addressing childhood obesity have had little success in reducing the prevalence of obesity or of returning children to a ‘normal’ BMI. Clinical guidelines recommend that health professionals from primary, secondary and tertiary settings should manage paediatric obesity. However, little is known about the current landscape of childhood obesity management: who is involved, what approaches are used, or what the main enablers or barriers to effective management are. Research has focused on the perceptions and practices of Australian general practitioners, but little is known about the experiences of other health professionals who manage childhood obesity. The purpose of the study was to explore and describe how Australian health professionals and parents experience and perceive childhood obesity management. The aim was to access information that related particularly to facilitators and barriers of management. Methods: Interpretative phenomenological analysis was used as an approach to examine and describe factors that influenced the ways in which health professionals and parents experienced and perceived the phenomenon of childhood obesity management. Semi- structured interviews were undertaken with health professionals and parents. The research comprised two studies. Study 1 involved health professionals from private practice, weight-management clinics, hospital and community services in three Australian states. Participants were dietitians, paediatricians, psychologists, physiotherapists and endocrinologists. Study 2 presents four case studies of parents who had attended a paediatric weight management clinic. Findings: Health professionals described childhood obesity as a body size that put children at risk of poor health outcomes; the psychological impacts were particularly of concern. They discussed their perceptions of their role in diagnosis, assessment and treatment; and shared their experiences of carrying out these roles. Each perceived role was described in the context of barriers that presented both internal and external to the clinical management setting. This included a paucity of services to refer children with obesity, insufficient resources to support treatment and their inadequate knowledge/training to engage families and effectively implement prescribed changes to health behaviours. Furthermore, health professionals believed changes made during clinical interventions were unsustainable because of the impact of the wider environment, particularly ease of access to calorie-dense foods, sedentary activities and family circumstances. The implications of the obstacles health professionals faced in treating childhood obesity were evident in parents’ interviews. Parents reported: difficulties accessing services due to limited availability and work hours; problems getting the whole family to attend sessions; resistance from other family members, including the children themselves. They believed health professionals played an integral role in gaining the entire family’s support. Parents wanted better strategies that would help their family more readily accept changes; however, they also acknowledged ensuring every meal for children was healthy was difficult due to the impact of an obesogenic environment. Ultimately, parents felt more in control of their family environment but were not confident these changes could be sustained, particularly when children were out of their direct care. Conclusion: Childhood obesity management may benefit from a systems approach. This includes having a health infrastructure and training that supports the practices of health professionals so that optimal management can be achieved. Additionally, policies that address the environmental and social determinants of childhood obesity are required to support sustainable behaviour change initiated by clinical management.

In Australia obesity is constructed by governments as a leading risk factor for major, preventable, non-communicable chronic disease. To investigate the failure of obesity policy to stop or reverse the prevalence of obesity in Australia over the last two decades calls have been made to better theorise obesity as a problem. Social constructionism is identified as a useful theoretical approach to analyse entrenched and socially complex policy problems. Based on social constructionism a Critical Social Constructionism methodology is created for use in this thesis and is based on aspects of Bacchi’s critical policy analysis methodology, ‘What’s the problem represented to be?’. The Critical Social Constructionism methodology is a practical and effective tool to critically analyse the policy problem representation of obesity. A specific example of obesity policy, the Australian Government Measure Up campaign along with the historical and broader policy context of that campaign are analysed. This analysis is assisted by the production of a schema of obesity representations that differentiates biomedical and social representations of obesity and by interviews with experts in obesity and preventive health issues. It is widely agreed in critical literature that the biomedical paradigm which was developed in response to acute and infectious diseases constructs health problems in a reductionist and individualistic way. The first major conclusion of this thesis is that the current dominant obesity problem for policy is constructed in a biomedical model with important underexplored effects. A second major conclusion holds that changing what the problem is represented to be from a biomedical representation of obesity to a social health representation faces extraordinary barriers that make such a project both impractical and improbable. Therefore this work explores the possibility of a radical disruption of the representation of the problem as obesity in policy. Alternative, ‘weightless’ representations of the problem within current research, public programs and medical practice are described and proposed for consideration in future policy making aimed at more effectively reducing the rates of major, preventable, non-communicable chronic diseases in Australia.

As obesity prevalence continues to rise, approximately one third of patients seen by Australian general practitioners (GPs) are living with obesity. General practice is the cornerstone of primary care in Australia with 85% of the population seeing a GP at least annually. The current role of the GP in obesity management focuses on care co-ordination with guidelines encouraging the referral of patients to allied health services, including dietitians and exercise physiologists. But multidisciplinary team care is not always available due to factors such as location and cost, or patients may have a preference for working more closely with their GP. Currently there are no weight management programs where care is delivered by a GP. This doctoral work explores the current role of the GP in obesity management in Australia, outlines an intervention development study for a GPdelivered weight management program, and presents the findings of a feasibility trial of the program. Following the UK Medical Research Council’s Guidelines for the Development of a Complex Intervention, a GP-delivered weight management program was developed. The draft program was based on Australian evidence-based guidelines for obesity management and used a qualitative approach to engage stakeholders to refine the program materials. Following this intervention development, a six-month feasibility trial was undertaken in five general practices involving 11 GPs and 23 patients. Guided by Normalisation Process Theory, both quantitative and qualitative data were collected. Both GPs and patients reported high rates of acceptability and feasibility, and there was a low dropout rate with only three patients withdrawing. Based on the theoretical framework of Bordin, patients and GPs with a strong therapeutic alliance had better program retention and there was a trend to improvement in some health outcomes. Social cognitive theory suggests that “performance mastery” is the most effective way to develop self-efficacy. This was demonstrated in the feasibility trial with both qualitative and quantitative data showing the GPs improved self-efficacy for obesity management. Based on the findings in the feasibility trial, a modified approach to obesity management in primary care is suggested with a greater emphasis on therapeutic relationship, person-centredness, and the explicit recognition that care occurs over time and not within one consultation. A GP-delivered weight management program in Australia was demonstrated to be feasible and acceptable to both patients and their GPs. Future research will focus on a pseudo-cluster randomised controlled trial for effectiveness, alongside further development of a measure for therapeutic alliance in general practice for research, teaching, and clinical purposes.

Research Doctorate - Doctor of Philosophy (PhD)
Overweight and obesity are highly prevalent conditions that impose a substantial burden on the individual and the society. As the gateway to the health care system, general practice is a promising setting to deliver interventions targeting overweight and obesity. While there has been increasing discussion regarding the role of general practitioners (GPs) in weight management, only a small proportion of overweight and obese patients are offered assistance with managing their weight. The 5As framework (Ask, Assess, Advise, Assist and Arrange) is recommended for the detection and management of lifestyle risk factors in primary care. This framework provides a structure for identifying gaps in the current literature in relation to weight management. The body of research described in this thesis is designed to provide key data in each of the 5As in the framework, to contribute to improving the provision of weight-management care in the Australian general practice setting. The contents of this thesis by publication include an introduction, five data-based manuscripts, a systematic review and a general discussion. At the time of thesis submission, three papers have been accepted for publication in peer-reviewed journals, and the remaining three are under editorial review. These papers examine the measurement and assessment of overweight and obesity and their associated risk factors (Papers One to Three), the effectiveness of lifestyle weight-loss interventions involving GPs (Paper Five), and overweight and obese patients’ current practices and preferences for help with losing weight (Papers Four and Six). The empirical data reported in Papers One to Four, as well as Paper Six, are obtained from the “General Practice Study”, a large, multi-state, cross-sectional study examining the feasibility of implementing computerised health assessments amongst patients presenting to general practices.

Overweight/obesity rates in children of immigrants from low-and-middle-income-countries not only eclipse rates in their origin countries, they also exceed rates in their host nation. My mixed-method research seek to understand this conundrum, to inform a more effective, and equitable prevention agenda. Using representative data from Birth cohort of the "Longitudinal Study of Australian Children", I quantified the prevalence and predictors of overweight/obesity in Australian-born children by maternal immigrant status. For the qualitative component, I interviewed immigrant mothers and their children, to understand how conflicts of culture and acculturation in the host countries contribute to greater risk in these children. My first paper confirmed that not only do the children of mothers from low-and-middle-income-countries matched the overweight/obesity rates of children of Australian-born mothers, they superseded them at most ages. The difference was significantly higher in boys at 8-9 and girls at 4-5 years. Furthermore, this excess risk was not simply due to family socioeconomic-position, as is commonly assumed. My second paper explored the reasons for this excess risk. Unhealthy diet and insufficient physical activity were pronounced in children of mothers from low-and-middle-income-countries. This difference in risk factors- particularly in boys - appeared to explain part of their excess risk relative to children of Australian-born mothers, signalling potential cultural and gendered reasons for this difference. My third paper explored differences in BMI-trajectories, questioning association of this excess risk with different developmental patterning. Children of mothers from low-and-middle-income-countries were more likely to have high-and moderate-risk BMI-trajectories and less likely to have low-risk BMI-trajectories. Factors associated with high-moderate risk BMI-trajectories were high birthweight, low socioeconomic position, high screen time and non-participation in organized sports. The dramatic changes in some BMI-trajectories between the ages of 4-7 years reveal how important this period may be for prevention. In the fourth mixed method paper using a more child-centred lens, I explored how children's body image and culture may be linked. Approximately three-quarters of children aged 10-11 years had body image dissatisfaction and were trying to manage their weights. This proportion was even higher in children of mothers from low-and-middle-income-countries. Maternal body image standards were drawn from their origin countries - heavier bodies were considered healthy for younger children and adolescent boys but thinner bodies for adolescent girls. Their children, however, perceived heavier bodies undesirable and unpopular. Finally, I explored acculturation challenges amongst mothers and children. At home, origin countries traditions were followed. Culturally meaningful celebratory foods, often high in sugar and fats, were frequently consumed. Mothers prioritised education, religious and cultural activities over sports. Children wanted to be as physically active as Australian peers, but felt restricted by maternal fear of racism and discrimination. The restrictions were higher for girls. In summary, unhealthy diet and low physical activities expose these immigrant children to adiposity from an early age. Cultural differences increases risk because physical activity and food is imbued with culturally important (and gendered) meanings fundamental to identity. Preventive strategies must go beyond simplistic health messages by accounting for diverse cultural framings of health, food, weight and activity among immigrants. Early engagement of immigrants with more nuanced, culturally respectful, gender specific, preventive health messages is required.

Atrial fibrillation is the most common heart rhythm disorder. Once considered to be a benign condition, it is now known to be associated with significant morbidity and mortality. The rising incidence and prevalence of atrial fibrillation has thus led to growing concern by clinicians and policymakers. In recent years, there have been marked strides in our mechanistic understanding of atrial fibrillation that, coupled with technological advances, have allowed for many new therapies. Despite the resultant explosion in research on atrial fibrillation, however, innumerable uncertainties regarding this intriguing arrhythmia still remain. This has provided fertile ground for the work undertaken as part of this thesis and future research on this condition. Previous studies contributing to our current understanding of atrial fibrillation are first reviewed in Chapter 1. Chapter 2 subsequently characterises the population burden of atrial fibrillation on the Australian healthcare system by analysing nationwide trends in hospitalisations. To provide some insight into the determinants of such healthcare utilisation, and how they may potentially be modified, Chapter 3 analyses relevant patient- and management-specific factors as they pertain to these trends. Data on two other cardiovascular conditions, myocardial infarction and heart failure, are contrasted with those for atrial fibrillation to provide context and insight into these trends. Given the emerging epidemic of obesity, Chapter 4 characterises the contribution of obesity to the risk of atrial fibrillation in various clinical situations by undertaking comprehensive systematic reviews and meta-analyses. In Chapter 5, the possible contribution of pericardial fat in mediating the the relationship between obesity and atrial fibrillation is further studied. In Chapter 6, race-specific differences in atrial fibrillation are explored by analysing differences in the prevalence of atrial fibrilllation between Indigenous and non-Indigenous Australians. An insight into possible mechanisms underlying these differences are subequently provided by studying cardiac structural characteristics. Given the greater prevalence of atrial fibrillation and burden of stroke experienced by Indigenous Australians, in Chapter 7 the race-specific management of atrial fibrilation is characterised with regards to anticoagulation practices. Finally, insights into the epidemiology, pathogenesis and management of atrial fibrillation from the research presented in this thesis are placed in the context of the previous literature in Chapter 8, before possible directions for future studies on atrial fibrillation are discussed in Chapter 9.
Thesis (Ph.D.) -- University of Adelaide, School of Medicine, 2015.

Research Doctorate - Doctor of Philosophy (PhD)
According to the Barker theory and Developmental Origins of Health and Disease (DOHaD) hypothesis, an impaired intrauterine environment, caused by exposure to maternal insults such as poor nutrition, severe stress or illness, can exert permanent effects on the developing fetus and increase the risk of offspring developing adult-onset diseases. These include: cardiovascular disease (CVD), hypertension, obesity, type 2 diabetes and metabolic syndrome, as well as chronic kidney disease (CKD). In animal models, maternal insults such as protein restriction or diabetes during pregnancy result in altered development of the fetal kidney and impaired renal function in later life. The age-adjusted incidence of end stage kidney disease for Indigenous Australians is 6.8 times the rate for non-Indigenous Australians, with rates highest in remote and very remote areas of Australia. This huge disparity may originate through exposure to various maternal insults in utero. Therefore, the overall aim of my thesis was to address the evidence gap in research investigating the relationship between maternal nutrition, obesity and diabetes during pregnancy and offspring kidney structure and function in an Australian Indigenous population and to identify pathways to improve health outcomes for Indigenous communities. Most of my thesis utilised data from the Gomeroi gaaynggal programme, which is a prospective longitudinal cohort of Indigenous Australian mothers and their children residing in a rural region of New South Wales, followed from pregnancy through the postnatal period until the children reach 10 years of age. A cross-sectional study assessed nutrient sufficiency and diet quality in pregnant women from the Gomeroi gaaynggal cohort (n = 58). Maternal dietary intake during pregnancy was assessed using the Australian Eating Survey Food Frequency Questionnaire (AES FFQ), which was self-administered in the third trimester. Diet quality was determined using the Australian Recommended Food Score (ARFS). None of the women met all Australian Guide to Health Eating (AGHE) daily food group serving recommendations and only one person consumed the optimal level of specific nutrients (folate, iron, calcium, zinc and fibre) important in pregnancy. The data indicated that the diets of these Indigenous pregnant women were inadequate. A systematic review of the literature was used to identify and evaluate current research in humans that had examined the relationship between maternal nutrition, obesity and/or diabetes during pregnancy and offspring kidney structure and function. This review identified ten studies investigating the influence of maternal nutrition during pregnancy on offspring kidney outcomes and nine studies investigating the influence of maternal obesity and/or diabetes during pregnancy on offspring kidney outcomes. This area of research is relatively new and an emerging one given the majority of studies included were published since the year 2010. Studies were of low to moderate methodological quality. The results of the review aimed to highlight the research gap and provide direction for future longitudinal prospective studies, especially in Indigenous populations where the risk of renal disease is greater. Animal research is valuable in the understanding of DOHaD. Systematic reviews of animal research are rare but crucial to improve translation of animal data to clinical practice. My systematic review of animal studies investigating the influence of maternal global nutrient restriction during pregnancy on offspring kidney structure and function is novel. 28 studies met the inclusion criteria: 16 studies were on rats, nine on sheep, two on baboons, and one on goats. The available evidence from these studies suggested that exposure to maternal global nutrient restriction during pregnancy had detrimental effects on offspring kidney structure and function. This systematic review highlighted the need for improvement of the internal validity of animal studies. Recommendations put forward included randomisation of animal into experimental groups and blinding of handler and outcome measure. Suggestions for future research, such as methods to appropriately determine nephron number were also detailed in the chapter. A prospective longitudinal study examined the influence of maternal adiposity and birth outcomes on childhood obesity in an Indigenous Australian population participating in the Gomeroi gaaynggal study (n=227). Findings suggested that being born preterm, large for gestational age or exposed to an obesogenic intrauterine environment and higher maternal non-fasting plasma glucose concentrations were associated with increased obesity risk in early childhood. Another study examined the influence of maternal adiposity during pregnancy on fetal kidney structure in late gestation (>28 weeks) and kidney function in infants, <2.5 years of age, in an Indigenous Australian population. Our findings suggested that Indigenous babies born to obese mothers were likely experiencing glomerular hyperfiltration in utero possibly because nephron number was reduced relative to body weight, which may predispose them to increased risk of CKD in later life. No effect on renal function was observed in infants, however, long-term follow-up was needed to determine any impact to renal function in later life. These studies provided first evidence of such associations in Aboriginal and Torres Strait Islander Australians. This thesis identified that, in humans, deficiencies in maternal folate, vitamin A, and total energy during pregnancy were associated with detrimental impacts on kidney structure and function, measured by kidney volume, proteinuria, estimated glomerular filtration rate (eGFR) and mean creatinine clearance in the offspring. Intrauterine exposure to maternal obesity and/or diabetes also adversely impacted renal programming in human offspring, with an increased risk of kidney disease in adulthood. In animals, exposure to maternal global nutrient restriction during pregnancy had detrimental effects on offspring kidney structure and function, such as lower kidney weight, lower nephron endowment, larger glomerular size and lower GFR. Furthermore, this thesis highlighted key areas for improving the dietary intake of Indigenous Australian women during pregnancy. To our knowledge, this thesis provided the first evidence that exposure to maternal obesity during pregnancy increased kidney disease and obesity risk in the offspring in an Indigenous Australian population. There are gaps in the current literature investigating the influence of maternal nutrition, obesity and diabetes during pregnancy on offspring kidney development and function in humans as well as in animals. Directions for future practice and research were discussed in the relevant chapters. This thesis provided evidence in the field of developmental programming of kidney disease in the Indigenous Australian population and will inform the development of government public health policies. In doing so, not only will the burden of kidney disease be reduced, the health, cultural and material wealth of Indigenous Australians will potentially improve. This is a long-term investment by the researchers in collaboration with the wider Indigenous community and with community consultation with the Elders.

Obesity is a global problem affecting the biopsychosocial well‐being of approximately six hundred million adults globally (WHO, 2015). To date, the deleterious effects of obesity have attracted a wide range of treatment approaches with two things in common. The first is an almost exclusive focus on pathology in an attempt to alleviate distress and dysfunction, and the second is a high rate of relapse. This has prompted scientists to explore new approaches to facilitate weight loss, to prevent weight regain, and to improve quality of life for people struggling with weight related issues. Over the last two decades the field of positive psychology has sought to balance and enhance our traditional approach to disease management via promotion of positive thinking, feeling and behaviour across a broad range of disorders. Positive psychotherapeutic strategies have been applied to mood disorders, psychiatric illness and addictive disorders with results suggesting improvement in biopsychosocial resources and health (Kahler, Spillane, Day, Clerkin, Parks, Leventhal & Brown, 2014; Meyer, Johnson, Parks, Iwanski & Penn, 2012; Ruini & Fava, 2009; Seligman, Rashid, & Parks, 2006). However, the application of a positive psychological approach to weight loss and maintenance in obese populations is lacking. This body of work explores the hypothesis that obese populations may be languishing, that is experiencing a state of incomplete mental health characterised by low levels of mental illness and low levels of subjective well-­being (e.g. Keyes & Lopez, 2002). In this broad context, subjective well-­being refers to perceptions and evaluations of one’s life in terms of affect (the presence or absence of positive feelings about life), psychological health (the presence or absence of positive functioning in life) and social functioning (self‐assessed quality of societally based experiences (Diener, Wirtz, Tov, Kim-­Prieto, Choi, Oishi & Biswas-­Diener, 2010; Keyes & Magyar Moe, 2003; Keyes, Shmotkin & Ryff, 2002). We also posit that the experience of obesity, characterised by negative mood states, a lack of functioning and social isolation (Thomas, Hyde, Karunaratne, Herbert & Komesaroff, 2008), is sufficiently negative to create unhelpful physiological changes, and a narrowing of functional behavioural strategies serving to deplete personal resources and motivation (Fredrickson, 1998; Fredrickson & Joiner, 2002; Lazarus, 1991; Levenson, 1994). To the best of the researcher’s knowledge this thesis is among the first to consider positive mental health variables as viable adjuncts to traditional strategies, in the service of improving outcomes in this often treatment resistant population. Given this is a new area of research, a mixed-­methodology involving qualitative and quantitative analyses served to inform and guide each study, and to provide a deeper insight into how a positive psychology approach might benefit obese populations. The results of three independent but related studies are presented in two published and two submitted papers. Paper one (study one) reports the results of a qualitative study exploring the ‘lived’ experience of obese Australians (N = 22) during weight loss attempts, interpreted with reference to the positive psychological concepts of Subjective Well-­‐being (SWB), Psychological Well-­‐Being (PWB) and Social Well‐Being (SLWB). Findings suggest the majority of our participants were languishing during their weight loss experiences, evidenced by a lack of domain specific SWB, and only four of the possible eleven domains of PWB and SLWB required for complete mental health being subjectively endorsed. This provided preliminary support for our hypothesis that a state of languishing may serve to contribute to, or maintain obesity in some individuals. A benefit associated with the qualitative approach involved the ability to identify the presence of positive psychological variables existing outside of the weight loss domain. This served to contribute a more balanced and realistic picture of the obesity experience than traditional, domain specific quantitative approaches could offer in this early stage of investigation. Themes promoting positive mental health were identified including Motivational Forces and Self-­View, indicating strengths, gratitude, hope and life satisfaction may potentially be useful areas to direct further investigation. Paper two (study two) served to quantitatively verify and extend our preliminary findings, providing a vehicle through which we could identify potential differences in positive psychological correlates across weight categories including normal, overweight and obese classes one to three. The main findings of this cross-­sectional study using an online survey method (n=260) suggest the category two and three obese demonstrated significantly lower scores on flourishing in comparison with the normal and overweight. The class three obese also demonstrated higher depression, and lower scores on agency, gratitude, positive affect and strength use in comparison with the normal and overweight. Results provided preliminary support for the hypothesis that a lack of well‐being may contribute to atypical BMI. In addition, the treatment needs of obese categories may differ, requiring specifically targeted interventions to improve treatment outcomes. Paper three (study two) extended our previous findings and the maintenance literature by comparing the well-­being characteristics of successful weight maintainers (intentional loss of at least 10% body weight for at least 12 months) and non-­maintainers, using the same dataset. Results from this cross-­sectional online survey (N =250) suggest maintainers reported more frequent positive mood states and agentic thinking, both correlates of psychological health. They also engaged in more frequent diet, exercise and self-­weighing behaviours in comparison with non-­maintainers. However, despite achieving the physical health benefits assumed to be present post 10% weight loss, maintainers did not report being happier or more satisfied with life. Incorporating results from paper two, it was hypothesised that perhaps for some people, achieving weight in the ‘normal range’ (found to be associated with a flourishing state) may be more important than the achievement of successful weight maintenance. It was also hypothesised that the resultant dissatisfaction may serve to interfere with the sustained goal directed behaviour required for continued weight maintenance, perhaps leading to relapse. Based on results from papers two and three, it was proposed that for some obese individuals a Positive Psychological Intervention (PPI) may enhance well-‐being via broadening and building behavioural repertoires to achieve happiness, and perhaps as a by-­product of this process, achieve weight loss. Paper four (study three) reports the results of a pilot uncontrolled study (N =4) using a mixed methodology investigating the potential benefits of a brief PPI teaching Hope, Strengths and Gratitude to women with class two and three obesity. Four participants were assessed using a mixed-‐methods approach at baseline, post module, post course and at 3-­month follow-­up to establish the feasibility, tolerability, teachability and impact of the intervention on a number of outcome variables including weight, Subjective and Psychological Well‐Being and mood states. Results indicated the program was teachable, feasible and tolerable. In addition, preliminary data based on reliable and clinically significant change analyses suggest the majority of women experienced short-­term improvements in weight loss, positive mood states, flourishing and satisfaction with life, as well as a reduction in depression, anxiety and stress. These results provided preliminary support for the hypothesis that for some people, the promotion of positive psychological health may be helpful to sufficiently broaden and build behaviour conducive to maintainable weight loss success. The current findings are new, and may be useful for the development of strategies to promote well‐being in obese populations. First, the state of languishing may be an important contributor to the failure of current biopsychosocial approaches to facilitate weight loss and maintenance behaviour in the obese, and requires further consideration. A more balanced approach promoting the health and psychological benefits of well-­being may serve to encourage flourishing, leading to improvements in outcomes in this often treatment resistant population. Second, the treatment needs of languishing individuals may differ across weight categories requiring specifically targeted interventions to achieve successful outcomes. Third, the understanding that the health benefits achieved via the recommended 10% weight loss may be insufficient as a stand-­alone measure of success in weight maintenance. In addition, the facilitation of flourishing despite current atypical weight may serve to assist with motivation to continue with maintenance behaviour, improving physiological reactivity and mood to reduce the risk of relapse. Fourth, specifically targeted Positive Psychological Interventions (PPI) promoting well-­being may promote short-­term improvements in the positive mental health, happiness and weight loss outcomes of the class two and three obese, beyond the benefits traditional strategies can offer, making PPI’s a potentially useful adjunct to current treatment strategies. Further investigation and refinement of these preliminary findings may promote sustainable weight loss, and reduce the burden of disease and illness currently experienced by six hundred million individuals worldwide (WHO, 2015).
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Psychology, 2015.

Research Doctorate - Doctor of Philosophy (PhD)
The rising prevalence of overweight and obesity, the health and financial consequences associated with weight gain, and the modest and often unsustainable weight loss from obesity treatment interventions mean that it is now considered more effective to prevent obesity in healthy weight and overweight populations. Mid-age women (45-54 years) are at high risk of weight gain and studies indicate women will likely continue to gain weight and increase their waist circumference post menopause unless effective weight gain prevention initiatives are implemented. Despite this, there is limited evidence for weight control interventions in women about to undergo the menopause transition, with only one published study. The primary purpose of this thesis was to determine the effectiveness of a 12-month health professional Motivational Interviewing (MI) intervention aiming to improve dietary intake and physical activity behaviours for weight gain prevention in non-obese, mid-age women. This thesis explored the use of MI, a client-centred, guiding counselling style, for dietary and physical activity behaviour change. Three research studies were undertaken to meet these aims. The first study was a systematic review of evidence for diet and physical activity behaviour change in response to MI interventions in comparison to an attention control. Two of the five articles reporting on dietary behaviour change found a significant positive effect on fat and percent energy from fat favouring MI. None of the six articles reporting on physical activity found any difference between MI and an attention control. Due to the limited number of studies and the poor methodological quality of the included studies, there is not yet sufficient evidence to conclude that MI enhances diet and physical activity behaviour change above an attention control, although the results from two studies suggest a positive effect. More high quality studies that objectively measure diet and physical activity, evaluate and report MI fidelity and compare the MI intervention to an attention control are required. The second and major study was the ‘40 Something’ parallel-group Randomised Controlled Trial (RCT) which tested the effectiveness of a 12 month MI health professional intervention (MI; n=28) for weight gain prevention in non-obese, mid-age women in comparison to a self-directed intervention (SDI; n=26) that received tailored written materials. The study followed participants for an additional 12 months to assess effect maintenance. At 12 months, the MI group weighed 65.6 kg (95% CI 64.5, 66.8) which was significantly different (p=0.034) from the SDI group who weighed 67.4 kg (95% CI 66.2, 68.6). When stratified by baseline BMI category, the MI group lost significantly more weight (-2.6kg, 95% CI -3.9, -1.2) than the SDI group (-0.1 kg 95% CI -1.2, 1.0 p=0.002) for the healthy weight women. The overweight women lost weight regardless of whether they were allocated to the MI (-3.5kg, 95% CI -6.1, -1.0) or SDI group (SDI=-2.3, 95% CI -4.1, -0.5) with no between group difference (p=0.467). At 12 months, the MI group had diets significantly more nutrient dense for iron (p=0.01) and potassium (p=0.04), and consumed more fruit servings (p=0.02) than the SDI women. Women who achieved their weight control goals consumed significantly more fruit servings (+0.76 serves/day, p=0.02) and less meat/meat alternatives (-0.34 serves/day, p<0.01) than women who did not achieve weight control. There were no significant group by time effects found for physical activity. In a mediation analysis assessing whether compliance to 10 weight control recommendations mediated weight loss, step count compliance was found to significantly mediate the 12 and 24 month effect on weight (12 months AB=-0.74, 95%CI=-1.95, -0.14; 24 months AB=-1.06, 95%CI=-2.56, -0.36). Compliance to the vegetable serving recommendation was also found to significantly mediate the effect on weight at 24 months (AB=-0.54, 95%CI=-1.50, -0.04). A challenge of employing any counselling style in dietetic practice is ensuring that the professional standards are upheld whilst also employing the most effective counselling method. The final study was an examination of United States, Canadian, European and Australian dietetic scope of practice statements, competency standards and evidenced-based weight management guidelines for congruency with MI principles and strategies. Two of the four MI concepts, partnership and compassion, were consistent with scope of practice statements and competency standards. Reference to acceptance was evident in European and Canadian standards, whereas evoking intrinsic motivation was absent from all standards. The majority of MI strategies were supported by international evidenced-based guidelines. The findings presented in this research thesis provide evidence of the effectiveness of a health professional consultation intervention for weight gain prevention and improving diet quality in mid-age women soon to experience menopause. Encouraging women to take 10,000 steps and eat five vegetable servings per day may be a promising strategy to achieve long-term weight control at mid-life. While there is substantial evidence showing the effectiveness of MI on a variety of health outcomes, more high quality studies that examine the effect of MI on diet and physical activity behaviour change are needed. The study also found that training in MI is compatible with international dietetic practice standards and could be a valuable asset to dietetic research and practice. The results of the thesis have implications for mid-age women, the dietetic profession and behavioural researchers, and provide both clinical practice and research recommendations for weight gain prevention and motivational interviewing.

In recent years research has recognised that notions of body image, body image ideals and body dissatisfaction develop much earlier than was once thought. However, the growing body of evidence in this area of research is predominantly quantitative. This study was designed to engage children in the five to six year age group using qualitative methods and present their notions of body image through the looking glass of the children's own eyes. Children's voices have not often found their way into research. Concerns about their powers of communication, cognitive abilities and the ethical difficulties inherent when working with children have restricted their participation. Objective, empirical evidence suggests that if one engages children in research appropriately they are able to make a significant contribution. Forty-seven children (25=m; 22=f) aged between five and six years were interviewed on three occasions over 12 months regarding their perceptions of body image. Seven schools from the Independent school system were involved. Interviews were conducted on school sites in public, easily observable locations. The study focused on three aspects. That is, how these children perceived their own body, the bodies of other people and their notions of health in respect to body image. These interviews revealed that the girls in this age group had developed an understanding of body image that valued thinness. However, their preference for a thinner body did not negatively impact on their sense of identity or self-worth. Boys preferred larger bodies and correlated increased body size with competence and physical aptitude. The concept of 'large' was linked to height for some or to a mesomorphic body for other boys. By the final interview all the children revealed strong negative perceptions of fatness. These perceptions were more apparent at each successive interview. An obese or extremely thin body was not always correlated with being unhealthy. Depending on the perspective of the child, even the largest of images was nominated the 'healthiest body' by some children. Health was overwhelmingly linked to food intake with few children associating health with exercise. The playground and the home, where most notably mothers, were important in the development of body image conceptions. Children were acutely aware of the dietary practices of their parents and associated diets with losing weight.
PhD Doctorate

Australian underutilised fish species, such as silver warehou (Seriollela punctata) and eastern school whiting (Sillago flindersi) as well as fish by-products may be potent sources of bioactive peptides. These species and/or their by-products are often wasted due to their poor technological and textural properties, and not acceptable for consumption by the Australian consumers. Interestingly, these fish wastes possess important nutritional value and physiological benefits, owing to their high protein content. Technological processing and the presence of endogenous enzymes in the fish muscle have the potential to release the so-called bioactive peptides during storage or digestion in the gastrointestinal tract. In the new era of the field of food science and technology, the production of bioactive peptides released from fish wastes is becoming increasingly important to preserve the marine sustainable environment and develop essential functional food to maintain human health as well as preventing the risks of developing certain types of metabolic diseases, like obesity and/or metabolic syndrome. As a result, the main focus of this project was to investigate the controlled hydrolysis of fish muscle proteins from by-catch fish species as a means of producing bioactive peptides with beneficial physiological properties. Important in-vitro bioactivities investigated could be related to the prevention of obesity and associated health complications. They include i) angiotensin-converting enzyme (ACE – hypertension) inhibition, ii) trypsin inhibition (satiety-induced) and iii) anti-oxidative (oxidative stress and inflammation-related conditions) activity.