The problem this thesis addresses is unhealthier diets consumed in high income countries that contribute to rising obesity rates. This problem is most evident amongst those in lower socio-economic positions (SEPs) who benefit less from traditional information-based interventions, possibly due to lower cognitive resource for self-control. Conversely, altering environmental cues appears to change behaviour with less conscious deliberation. This thesis aims to investigate whether interventions targeting the “proximity effect” i.e. the farther away the food, the lower the chance it is selected, consistently affects food selection in general populations in ways that could be used to improve diets without relying on cognitive resource. Three laboratory-based experiments were conducted. Study 1 investigated the proximity effect in a general population sample, including those from lower SEPs. Fewer participants selected an unhealthier food when it was far (53.8%) compared with near (63.3%), an effect which increased in size when participants who moved the bowl were excluded (39.3% vs 63.9%). Study 2 extended Study 1 using a statistically more powerful design in which participants were also randomised to a cognitive load intervention, assessing whether the proximity effect was similar regardless of differences in manipulated cognitive resource. Fewer participants selected an unhealthier food when it was far (57.7%) compared with near (70.7%) an effect not moderated by cognitive resource. Study 3 built on Studies 1 and 2, (in which only one unhealthier food was available), to assess the proximity effect when both healthier and unhealthier foods were available. The selection of healthier food was not significantly affected by its proximity (OR=0.61, 95% CI[0.28,1.32]) and that of competing unhealthier foods (OR=1.54, 95% CI[0.52,4.55]). By contrast, the selection of unhealthier food was influenced by its proximity (OR=0.39, 95% CI[0.18,0.82]) and that of competing healthier foods, although not significantly (OR=2.83, 95% CI[0.98,8.33]). These differing effects require further testing and replication to determine their reliability. The thesis concludes by discussing how the findings of these studies can inform development of interventions capitalising on the “proximity effect” to improve diets for all SEPs, the research needed to address key remaining uncertainties, and the implications of such interventions for addressing the rise in obesity.

The primary hypothesis of this study was that low-income individuals purchase more packaged foods of lower healthiness and lower price compared to similar packaged foods of higher healthiness and higher price. The Nutrition Metric was chosen as the system to measure the nutritional value of foods because it is in the public domain and uses nutrients common to the Nutrition Facts panel; however, prior to use, the validity of the Nutrition Metric needed to be tested. The convergent validation of the Nutrition Metric was tested with four systems (NuVal, Guiding Stars, WXYfm, Go-Slow-Whoa) that met the study criteria. A sample of 600 foods that were purchased over a 104 week period that ended in November 2009 by 34,407 low-income households was drawn to achieve at least 168 items having scores available for each system. The Nutrition Metric had a positive correlation with all scoring systems for the 174 foods (P<0.01) that verified its validity as a tool to assess food healthiness. The Nutrition Metric was used to measure the healthiness of packaged products from the list of low-income food purchases (n=316). Products had a negative mean healthiness score of -0.88 ± 1.72 and low levels (<5% Daily Value) of dietary fiber, vitamin A and C, iron, and cholesterol. The majority of the products (n=305) did not have a nutrient claim on product packaging. The Nutrition Metric was a successful tool that can be utilized to assess the healthiness differences between products with and without nutrient claims purchased by low-income shoppers with counterpart products at the supermarket. Food price and healthiness differences were evaluated for the list of packaged products (n=305 (minus 11 single ingredient cooking staples)) commonly purchased by low-income shoppers to counterpart products of the same brand and package size with or without nutrient claims. Products with nutrient claims (n=77), on average, had higher healthiness scores and prices than products without claims (n=77) (P<0.01). Research and education initiatives that promote the selection of products with claims instead of products without claims are potential options to improve the diets of low-income consumers. / text

Background: Childhood, adolescent, and adult obesity is a major health and economic concern affecting the United States and various countries across the globe. Obese children and adolescents are at a potential risk for developing certain chronic diseases as they transition into adulthood. There are community-based cooking intervention programs designed to increase children and adolescents' intake of fruits, vegetables, and whole grains, whether these programs improve self-efficacy and perceptions related to food and eating behaviors is not currently known. Objective: The aim of the study was to evaluate the effectiveness of Teen Cuisine, an Extension-based cooking program on self-efficacy with cooking and perceptions of their eating behaviors in a diverse group of adolescents across the Commonwealth of Virginia. Subjects: Students involved in the 4-H Teen Cuisine Program during the 2013-2015 academic years. Cooking Program: Teen Cuisine is a six-week 90-minute extension-based cooking program created by the Virginia Family Nutrition Program targeting adolescents and teens throughout the Commonwealth of Virginia. The program focused on kitchen safety and sanitation, knife skills, food preparation, and nutrition education. Measures: A survey was used to assess n=531 student's self-efficacy for general nutrition knowledge, food choices, and cooking skills as a result of the 4-H Teen Cuisine Program during the academic year of fall 2013 to spring 2015. Methods: Surveys were administered upon completion of the Teen Cuisine program to assess students' self-efficacy and perceived gains in kitchen skills, dietary patterns and preferences, and nutrition knowledge. Results: Teens that self-reported living in rural areas throughout the Commonwealth of Virginia perceived gains (p < 0.05) in an increased consumption of fruits and vegetables. Teens also indicated an increased frequency in cooking and a decrease in their consumption of soda/soft drinks. Conclusion: Overall Teen Cuisine was found to be effective in improving perceptions of curriculum specific health behaviors, cooking skills, food safety and sanitation, and perceived gains in self-efficacy in the kitchen. / Master of Science

Young children have becoming an important target by marketers. Marketers have used many strategies to influence their food choices including advertising and free gifts. According to literature, young children, are cognitively vulnerable and may make unhealthy decisions about their food choices that could lead to serious problems associated with being overweight and obese. This thesis examines whether price and health claim information can shift young childrens' choices towards healthier foods. Most of the previous published research literature has focused on adults. Those findings, using surveys and experiments, suggest that adults' food preferences and choices can be influenced by setting price and by providing health information. These findings suggest that these strategies may have a potential effect in young children decision making. The literature on Children Socialization and Information Processing Theory in consumer behaviour suggests that most young children under 8 are not cognitively skilled to use price and health claim information for their decision making. Nonetheless, most 5 to 8 year olds are making purchases of food at their school canteen several times a week. In order to test for the effects of price and nutrition information, several experiments that used discrete choice modelling were conducted to determine their choices, the reliability of their choices and the between their experimental choice behaviour and their choice in the market place. More than one hundred young children, aged from five to eight years old, completed the discrete choice experiments conducted in two primary schools in the suburbs of Perth. The choice experiments on subjects that had previous experience with the food items, but did not know their relative nutritional value, showed a strong positive effect of price. In other words, higher priced options were often in more demand. Although this may appear a poor response to price by an observer, children have little knowledge of food costs, so they may use price as a surrogate for quality. Price level was also a main effect in reducing the share of unhealthy choices. The results of the analyses also show that young children can provide reliable choice decisions within 5 months of experiment. However, their experimental choices were not associated with their later choices in the canteen. These findings provide evidence of the effectiveness of price and health claim information in changing young childrens' preference toward healthy choices, and the potential usefulness of using discrete choice techniques to shift children to more healthy food options.

Fried foods are delicious and enjoyed by almost everyone. However, they are not the healthiest foods to eat because of the amount of oil they contain. This thesis, sponsored by Moaero Company founder, Mr. Harrish Bhutani, intends to determine whether a simply designed centrifuge system can remove a reasonable amount of oil from fried foods after it has been deep fried without adversely affecting the texture of the fried food. Due to a large variety in the texture as well as the type of fried foods, and in order to keep the scope of this thesis more focused and feasible, the focus of this investigation will be French fries. Three variables are tested: the type of fry, the angular velocity of the centrifuge, and the time spent in the centrifuge. Multiple designs for the centrifuge system were made on SolidWorks. Engineer Equation Solver (EES) was used to aid steady state and transient heat transfer calculations. Minitab was used for statistical analysis. The impact of various parameters on the change in mass of the French fries, as a measure for evaluating the oil content, were studied. The results indicate whether a centrifuge will remove a reasonable amount of oil while also considering the integrity of the fries. The study concludes that centrifugation is be a cost-effective method for removing oil from fried foods.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Burgers subjected to lipid reformulation were made by replacing 50% of the fat component by microparticles containing chia (CO) and linseed (LO) oils obtained by external ionic gelation. The microparticles presented high n−3 PUFAs levels and were resistant to the pH and temperature conditions commonly used in burger processing. The lipid reformulation did not affect hardness and improved important technological properties, such as cooking loss and fat retention. In addition to reducing the fat content of burgers by up to 50%, the lipid reformulation led to healthier PUFA/SFA and n−6/n−3 ratios, and lower atherogenicity and thrombogenicity indices. The burgers with CO microparticles showed a higher lipid oxidation and a lower sensory quality compared to the other treatments. However, the substitution of pork back fat by LO microparticles did not impair the sensory quality of burgers. Therefore, the microencapsulation of n−3 PUFA-rich oils by external ionic gelation can be considered an effective strategy to produce healthier burgers. / Hambúrgueres com uma reformulação lipídica foram produzidos através da substituição de 50% do seu teor de gordura por óleos de chia (CO) e de linhaça (LO) microencapsulados por gelificação iônica externa. As microcápsulas apresentaram altos teores de n-3 PUFAS e foram resistentes às condições de pH e temperatura comumente aplicadas durante o processamento de hambúrgueres. A reformulação lipídica não afetou a dureza e melhorou importantes atributos tecnológicos, como a perda no rendimento e a retenção de gordura. Além de reduzir em até 50% o teor de gordura dos hambúrgueres, a reformulação lipídica tornou mais saudável a relação PUFA/SFA e n-6/n-3 e os índices de aterogenicidade e trombogenicidade. Os hambúrgueres com CO microencapsulado apresentaram uma maior oxidação lipídica e uma menor qualidade sensorial. Por outro lado, a substituição de toucinho por LO microencapsulado não prejudicou a qualidade sensorial dos hambúrgueres. Pode-se concluir que a microencapsulação por gelificação iônica externa de óleos ricos em n-3 PUFAs pode ser considerada uma estratégia eficaz para produzir hambúrgueres com características mais saudáveis.

Sport and dance injuries have increased despite improvements in coaching techniques and medical care. Other factors, including psychological ones, were therefore thought to play a role in injury vulnerability. Most of the attempts to explain how psychological variables can affect an athlete's predisposition to injury have been based on anxiety or stress concepts. In this survey type study an interactive approach to stress has been adopted with the goal of finding a relationship between stress and injury in a group of professional ballet dancers. No simple direct relationship was found. Multiple regression analysis was performed and a more complicated relationship between stress indicators and injury was found. When an attempt was made to investigate the significant interaction, no significant correlations were found. However, the correlations were found to be large and negative. This could indicate that if the sample size had been larger significant correlations may have been found. / Psychology / M.A. (Psychology)

Sport and dance injuries have increased despite improvements in coaching techniques and medical care. Other factors, including psychological ones, were therefore thought to play a role in injury vulnerability. Most of the attempts to explain how psychological variables can affect an athlete's predisposition to injury have been based on anxiety or stress concepts. In this survey type study an interactive approach to stress has been adopted with the goal of finding a relationship between stress and injury in a group of professional ballet dancers. No simple direct relationship was found. Multiple regression analysis was performed and a more complicated relationship between stress indicators and injury was found. When an attempt was made to investigate the significant interaction, no significant correlations were found. However, the correlations were found to be large and negative. This could indicate that if the sample size had been larger significant correlations may have been found. / Psychology / M.A. (Psychology)

The South African fast-food industry is growing steadily, and so is the trend towards healthy eating. South Africans are becoming more aware of what they put into their bodies and not only do they want to consume meals that are quick and convenient, but they also want to ensure that what they are eating offers nutritional benefits. Although fast-food outlets have responded to customer demand by adding healthier food options to their menus, customer satisfaction regarding these options has not been investigated sufficiently in South Africa. The purpose of this study was to explore customer satisfaction with the healthier food options available at fast-food outlets in South Africa. An extensive literature review was conducted on the South African fast-food industry (the link between fast-food and obesity was noted, followed by a discussion on the trend towards healthy eating) and customer satisfaction. An empirical study was conducted, in which data was collected from students studying at the University of Pretoria by means of self-administered questionnaires. The study followed a mixed method approach, incorporating both qualitative and quantitative research in order to satisfy the research objectives. The results of this research study indicate that there is a high level of satisfaction amongst South African customers with the healthier food options available at fast-food outlets. / Business Management / M. Comm. (Business Management)

The South African fast-food industry is growing steadily, and so is the trend towards healthy eating. South Africans are becoming more aware of what they put into their bodies and not only do they want to consume meals that are quick and convenient, but they also want to ensure that what they are eating offers nutritional benefits. Although fast-food outlets have responded to customer demand by adding healthier food options to their menus, customer satisfaction regarding these options has not been investigated sufficiently in South Africa. The purpose of this study was to explore customer satisfaction with the healthier food options available at fast-food outlets in South Africa. An extensive literature review was conducted on the South African fast-food industry (the link between fast-food and obesity was noted, followed by a discussion on the trend towards healthy eating) and customer satisfaction. An empirical study was conducted, in which data was collected from students studying at the University of Pretoria by means of self-administered questionnaires. The study followed a mixed method approach, incorporating both qualitative and quantitative research in order to satisfy the research objectives. The results of this research study indicate that there is a high level of satisfaction amongst South African customers with the healthier food options available at fast-food outlets. / Business Management / M. Comm. (Business Management)