The Food Habits of Canadians Survey, conducted in 1997--1998 examined food and nutrient intakes of non-institutionalized adults aged 18--65 years (n = 1543) randomly selected from across Canada using the multi-stage random sampling strategy. Dietary intake was assessed by 24-h recall and a repeat interview was conducted in a sub-sample (n = 446). The overall response rate was 26%. Males, younger age adults (18--34 years), single persons and those with lower education levels were underrepresented in the study sample thus limiting the generalizability of the study results. Examination of the characteristics of the selected areas (n = 63) by response rates, indicated that areas with a higher percentage below the low income cut-off level, higher percentage who moved residence in the past 5 years and higher percentage speaking non-official languages as the mother-tongue were associated with low response rates. Additionally, areas with lower percentage females were associated with low response rates indicating that depending on the community characteristics different approaches may be needed to enhance response rates. Within- to between-subject variance ratios for several nutrients were higher when adjusted for age, gender, education, season, smoking and size of family compared to the crude ratios (e.g. for energy 1.07 vs. 0.49 for males). As a result, more days would be needed to reliably estimate usual intake once the data are appropriately adjusted. Examination of the within- to between-subject variability ratios for nutrients by smoking status indicated that the diet of smokers was no more variable than that of non-smokers. However, smokers had higher intakes of total fat (p < 0.05) and saturated fat (p < 0.05) and lower intakes of folate (p < 0.05) and vitamin C (p < 0.05). Smokers also had lower intakes of fruit and vegetables compared to non-smokers (p < 0.05). Given these differences, diet may be a confounder in studies examining smoking

Particularly in the health domain, humans thrive to reach an equilibrium between maximizing pleasure and minimizing harm. I propose that a cognitive strategy people employ to reach this equilibrium is the activation of Compensatory Health Beliefs (CHBs). CHBs are beliefs that the negative effects of an unhealthy behavior can be compensated for, or "neutralized," by engaging in another, healthy behavior. "I can eat this piece of cake now because I will exercise this evening" is an example of such beliefs. This thesis presents a theoretical framework which aims at explaining why people create CHBs and how they employ CHBs to regulate their health behaviors. The model extends current health behavior models by explicitly integrating the motivational conflict that emerges from the interplay between affective states (i.e., cravings or desires) and motivation (i.e., health goals). The first study includes a psychometric scale that measures CHBs in the general population and provides data on its reliability and validity. The results showed that scores on the scale were uniquely associated with health-related risk behaviors and symptom reports and could be differentiated from a number of related constructs. Holding CHBs may hinder individuals from acquiring healthier lifestyles, for example lose weight or exercise. The second large-scale study of this thesis aimed at studying CHBs in adolescents with type 1 diabetes. It is proposed that in this population, CHBs might interfere with treatment adherence. If compensatory behaviors fail to compensate for the maladaptive behaviors, poor blood glucose control and related health problems may arise. To investigate this further, I developed and validated a CHB scale specific to type 1 diabetes. The scale was validated in a sample of adolescents with type 1 diabetes. Results showed that holding maladaptive compensatory health beliefs was associated with poorer blood glucose control and poorer adherence to self-care behaviors while adaptive CHBs were associated with better blood glucose control and better adherence to treatment behaviors. Specifically targeting CHBs in an intervention could improve adherence to treatment and therefore the long-term health of this population. Future research as well as the implications for possible interventions are explicitly being discussed.

Dietary intake data of 15 treated patients with phenylketonuria (PKU) (7-17 years) and six control siblings (6-14 years) were used to evaluate the effectiveness of medical foods to balance energy, protein, vitamin B-6, and individual amino acids from natural foods and to evaluate vitamin B-6 status. Four-day diet records were computer-analyzed and the contribution of medical foods and natural foods to the total diets of the patients was determined. A fasting blood sample and two 24-hour urine collections were obtained from each subject. In eight patients consuming a strict diet, natural foods provided 0.9 g protein and 39 mg phenylalanine (phe)/100 calories, a significant reduction from control intakes of 3.3 g protein and 153 mg phe/100 calories. However, plasma phe levels were above the acceptable treatment range. Medical foods were consumed in less than the recommended quantities to meet approximately 120% of the Recommended Dietary Allowances (RDAs) for protein. These foods contributed 73% of the total protein RDAs but only met 22% of the energy RDAs of patients consuming the strict diet. Taste qualities of certain L-amino acids (L-AAs; Lmethionine, L-glutamic and L-aspartic acids), which constitute the protein in elemental medical foods (EMFs) for school-aged patients, make acceptance of these products difficult. Intakes of each of these L-AAs were above nutritional standards and suggested that their levels could be safely lowered in EMFs. Natural foods and medical foods provided 0.057 and 0.046 mg vitamin B-6/g protein, respectively, above the 0.020 RDA standard and the mean control intake of 0.018 mg vitamin B-6/g protein. The mean plasma pyridoxal 5'- phosphate (PLP) concentration for the patients with PKU was over twice that of the mean control concentration and above literature values. However, more than half of the patients excreted less than 30% of their vitamin B-6 as 4-pyridoxic acid; values below the criterion suggested for inadequate status. This work provides data for a better understanding of vitamin B-6 metabolism and status in PKU and supports the design and testing of a new EMF to balance energy, protein, and amino acids from natural foods and which may improve dietary adherence. / Graduation date: 1991

Elevated plasma lipids are risk factors for cardiovascular disease (CVD). In certain conditions plasma lipids are normal yet individuals experience increased morbidity. Type 1 diabetes (T1D) is associated with elevated CVD despite normal lipids, while in liver failure low plasma lipids may indicate increasing hepatic damage. Plasma lipids can therefore belie underlying dysregulated lipid metabolism. Islet (ITx) or liver (LTx) transplants represent therapies for T1D and liver failure, respectively, but are associated with altered lipid metabolism attributed to immunosuppressive medications; however, causative mechanisms are unknown. Partial success of dietary therapy in post-transplant patients may be due to interventions limited in scope. Regulation of plasma lipids involve absorption, synthesis, and clearance. These studies examined lipogenesis and cholesterol synthesis using deuterium incorporation. In brittle T1D lipogenesis and cholesterol synthesis were similar to healthy controls; however hepatic lipogenesis and cholesterol synthesis tended to be lower in T1D compared to matched control subjects. Plasma cholesterol was lower and triglyceride similar in liver failure patients compared to controls. Lipogenesis was higher while cholesterol synthesis was lower in liver failure compared to controls. Disturbances in lipid synthesis may be influenced by underlying disease, such as hepatitis C. In ITx and LTx lipogenesis was lower whereas cholesterol synthesis was similar compared to controls. Lipid synthesis is therefore unlikely to contribute to post-transplant hyperlipidemia, inviting investigation of other mechanisms. Dietary intervention emphasizing fish oil, phytosterols, soy, fibers, and almonds lowered plasma lipids in controls but had mixed effects in transplant subjects. Reduction in plasma lipids occurred in transplant patients with higher baseline lipids, suggesting this intervention may be successful in hyperlipidemic patients; however the potential of this diet intervention requires further study in hyperlipidemic patients. Diet intervention lowered lipogenesis but did not significantly change 24h cholesterol synthesis in controls. Diet did not change 24h lipogenesis or cholesterol synthesis in transplant subjects. Plasma lipid response to dietary therapy was related to baseline cholesterol synthesis and to dietary compliance in transplant subjects. Further study is required to determine if cholesterol synthesis is predictive of response to diet. / Nutrition and Metabolism

Due to the increase in type 2 diabetes in the child and adolescent population, examining the lifestyle habits of youth has become important. The purpose of this research was to examine the presence of dietary and physical activity risk factors for type 2 diabetes among youth in Alberta and to evaluate their relationship with insulin sensitivity. Lifestyle habits of Alberta youth with type 2 diabetes (n = 28), and age, sex and BMI matched controls (n = 28) were assessed by a chart review method. Those with diabetes had a higher intake of several nutrients (i.e. protein intake) and were less likely to be physically active. Dietary and physical activity risk factors for diabetes of a large sample of Alberta youth (n = 4981) were also assessed using the Web Survey of Physical Activity and Nutrition (Web-SPAN) and insulin sensitivity was measured in a sub-group (n = 318) using a C-13 glucose breath test. High Glycemic Index (GI) and Glycemic Load (GL) diets were common among Alberta adolescents and dietary patterns associated with dietary GI and GL were assessed. Dietary and physical activity risk factors for type 2 diabetes, including overweight and obesity, high GI, high GL, low fibre, low magnesium, low vegetable and fruit intake, high fat intake and low physical activity levels, were commonly reported among Alberta teens; with some risk factors, such as low fibre intake and high GI being reported by over half of all participants. Youth reported having an average of 3 diabetes risk factors. Boys reported more risk factors than girls, older students reported more risk factors than younger students and students with a higher BMI reported more risk factors than students with a lower BMI. Age, sex, BMI and dietary GI were associated with Insulin Sensitivity Score as measured by a C-13 glucose breath test. In summary, this research has shown that the dietary and physical activity habits of Alberta adolescents are sub-optimal for type 2 diabetes prevention and the relationship between diabetes risk factors and insulin sensitivity in this group suggests that these behaviours are related to early changes in carbohydrate metabolism. / Nutrition and Metabolism

No description available.

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1972. / Bibliography: leaves [179]-180. / Microfilm. / viii, 180 leaves illus., maps, tables

The population dynamics and fishery productivity of snapper, Chrysophrys auratus, in South Australia are strongly driven by inter-annual variation in recruitment. This variable recruitment produces the occasional strong year-class which, over a number of years, results in a cycle of increasing and then decreasing biomass. The aim of this study was to develop an understanding of the recruitment dynamics of snapper through a study of the reproductive biology of adults, as well as the biology and ecology of 0+ recruits. Field sampling was done through 2006 to 2008 in northern Spencer Gulf, the region that generally contributes the majority of South Australia’s snapper catch. The recruitment of 0+ snapper was measured from a study of inter-and intra- annual patterns of distribution and abundance. This was done using two independent trawl sampling regimes, one using a beam trawl and the other an otter trawl, at different times in the settlement season. There was considerable inter-annual variation in abundance of 0+ fish of up to two orders of magnitude and, in some years, almost no recruitment was observed. The spatial pattern of dispersion of recruits was clumped and consistent between years; one area, Western Shoal, always produced the highest catches indicating that it is an important nursery. The effects of the timing of spawning and water temperature on growth patterns of the 0+ snapper collected in the trawl sampling were studied to determine possible impacts on recruitment processes. Growth was studied from age/length regressions and by measuring the widths of microincrements in the sagittal otoliths. Sub-surface water temperature was also logged in the region. Growth rate varied inter- and intra-annually but was not limited by temperature in the pre-settlement period. However, post-settlement growth rate was significantly correlated with water temperature and fish exhibited a dramatic slowing of growth as temperature declined in autumn. Later spawned fish were considerably smaller than earlier spawned fish of the same age, which may have implications for post-settlement survival. The reproductive biology of snapper was studied to determine if annual variation in recruitment was related to egg production. Reproductive samples from northern Spencer Gulf were collected over three seasons (2005/06, 2006/07 and 2007/08) and were analysed macro- and microscopically. Spawning activity was determined by calculating estimates of spawning fraction and batch fecundities. The onset of spawning occurred in November but varied between years and corresponded with times when water temperature was between 18 and 20ºC. The length of the spawning season also differed between years. In each year the peak spawning activity occurred during December when fish spawned almost daily. Spawning frequency and relative batch size did not differ between the first two spawning seasons but, in the third season, batch size was considerably greater and spawning fraction lower. However, recruitment was considerably more variable than the annual differences in spawning output could explain. This indicates that mortality processes during the planktonic or early post-settlement period are important in the recruitment dynamics of snapper. The impact of water temperature, lunar cycle and tide on the timing and strength of recruitment was investigated. Pre-settlement duration, spawn dates and settlement dates were determined from the microstructure of the sagittal otoliths of 0+ snapper. The patterns of successful spawning and settlement were determined by back-calculating to the day on which individual recruits were spawned and settled. The frequency distributions of these dates were compared with water temperature, lunar periodicity and the temporal variation in spawning. There was considerable variation within a season in the timing and magnitude of successful recruitment. Strongest recruitment resulted from spawning during December and January on days when water temperatures were between 21 and 23ºC but spawning on days in this range did not necessarily result in recruitment. Pre-settlement duration was unaffected by water temperature. Some evidence of lunar periodicity was detected in both the spawn and settlement date frequencies. Importantly, the spawn date frequency distributions of successful 0+ recruits did not correspond with the measured spawning activity of adults as considerable portions of the spawning season in each year did not produce successful recruits. These results indicated that spawning output and water temperature cannot explain the observed magnitude in recruitment variation. Food availability for 0+ snapper has been implicated in their patterns of distribution and abundance in New Zealand and Japan. Stomach contents of 0+ snapper were described as an initial step in developing some understanding of the dispersion of 0+ recruits. In spite of their generalist feeding habit, in the area of highest abundance (Western Shoal), snapper took considerably more polychaetes than elsewhere in northern Spencer Gulf. If polychaetes are more abundant at Western Shoal, this could explain the higher density of 0+ snapper there but insufficient information was available on these animals for northern Spencer Gulf to address this hypothesis. Food availability and/or quality may influence the distribution of 0+ recruits. The multi-species collections from the beam trawls were described to develop an understanding of the spatial dispersion of recruits and their habitat associations. 0+ snapper co-occurred with an assemblage that was characterised by fish and invertebrate species that are associated with mud/soft bottom, but they never occurred with the assemblage of species associated with seagrass, even when recruitment was strongest. This association partly explains the observed distribution pattern, but not all areas of mud/soft bottom had 0+ recruits, even in strong recruitment years. In northern Spencer Gulf, seagrass areas could be excluded from future snapper recruitment surveys. The recruitment dynamics of snapper in northern Spencer Gulf were characterised by dramatic inter-annual variation but a consistent pattern of dispersion. 0+ snapper were concentrated in a few small areas in northern part of the study region. One of these areas, Western Shoal, appears to be very important as a nursery for snapper. Furthermore, the pattern of 0+ snapper dispersion was independent of recruitment strength. The potential magnitude of 0+ snapper recruitment, set by egg production, was altered by mortality during the early life history. Some of this mortality was related to temperature regimes at the time of spawning but this did not explain all the variation in the magnitude and timing of recruitment. Snapper spawning occurred at times with suitable temperature conditions but recruitment did not always result. This indicates the presence of other factor(s) that have substantial influences on mortality in the early life history. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1374397 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2009

This thesis investigates whether fats, akin to other taste stimuli, exhibit sensory properties such as mixture interactions. In order to determine gustatory, rather than tactile or olfactory effects, viscosity-controlled emulsions of deodorised oils were used as the base to which taste stimuli were incorporated and presented to a panel of trained assessors. In preliminary qualitative assessments, panellists described the 10% olive oil emulsion as saltier, stronger, fattier and having a more lingering aftertaste than the non-oil control, suggesting that oil modulates taste duration as well influencing taste intensity and/or perceived quality. Panellists were unable to rate the oil/fat taste per se with any degree of certainty hence further experiments examined the effect of oil on the perception of taste mixtures. In mixture interaction experiments, the addition of oil did not result in mixture suppression or enhancement for sweet, salty, sour or bitter while it significantly enhanced umami. To determine the locus of interaction, when MSG and oil were presented to each side of the tongue separately, the enhancement effect disappeared indicating a peripheral mechanism of interaction, similar to the attenuation of chilli burn by oil. In contrast, suprathreshold sucrose sweetness was enhanced by the contralateral presentation of oil, indicating sensory processing at a higher locus. Furthermore, the addition of oil significantly reduced bitterness in a caffeine-MSG mixture. Since earlier experiments did not indicate any interaction between oil and bitterness, the decrease in the perceived bitterness of this binary mixture is attributed to an increase in umami which is likely to have suppressed bitterness, the perceptually dominant component in this mixture. These findings suggest a gustatory role for fats in modulating the taste profile of mixtures, in particular, enhancing total taste intensity, prolonging taste duration, and enhancing umami. A taste receptor-based model of fat perception provides for an orosensory mechanism capable of signalling the arrival of the most energy-dense nutrient, essential fatty acids and fat-soluble vitamins. The chemosensory signal may also be the basis for hedonic responses with subsequent implications for intake.

Background The costs of healthcare are on the rise. With an ageing population, growing demand for health services and expensive new technologies, Australia’s annual health care bill has more than doubled in the last ten years, and is projected to increase a further 127% by 2033. As third-party provider of health care, the Government must make difficult decisions about how best to allocate limited resources to the many new and existing drugs, technologies and health services available for prevention and treatment of disease. Cost-effectiveness analysis of interventions can help identify those that should be given funding priority in order to maximise population health, but its use in allocating resources to prevention has been limited. There have been few cost-effectiveness analyses of preventive interventions, particularly for the potentially more effective strategies targeting the whole population, such as taxation, regulation and community campaigns. Current methods are poorly designed for capturing the change in population distribution of risk that can occur with these types of interventions. Use of cost-effectiveness analysis has also been limited by the use of many different (and often simplistic) modelling methods and assumptions that prevent league table comparison of results to help identify most cost-effective strategies. This thesis presents new methods for evaluating cost-effectiveness of preventive interventions, with application to interventions promoting physical activity, preventing alcohol misuse, reducing body mass, promoting fruits and vegetables and reducing dietary salt intake, from an Australian health sector perspective. Methods Proportional multi-state life table models were developed for each risk factor and for risk factor combinations, using population impact fraction (PIF) functions to quantify the potential intervention impact of a change in individual or population risk factor exposure on disease and injury. The models were used to simulate population health in disability-adjusted life years (DALYs) and costs of disease treatment, over the lifetime of the Australian population in 2003, for a range of individual- and populationtargeted interventions using intervention costs and effects derived from Australian cost data and published evaluation studies. Monte-Carlo analysis was used to derive uncertainty around all outcome measures, and sensitivity of results to key modelling choices and assumptions was also evaluated. Cost-effectiveness of six physical activity interventions, ten alcohol interventions, two body mass interventions, 23 fruit and vegetable interventions and four dietary salt interventions was evaluated in comparison to current Australian practice. In addition, where multiple mutually-exclusive interventions were evaluated, a partial null (‘no current practice intervention’) scenario was calculated and cost-effectiveness of incrementally adding each intervention to a package was evaluated, to determine the optimal intervention mix and to compare optimal outcomes with the current practice. Findings For physical activity, a package of six individual- and population-targeted interventions is cost-effective and could avert a third of disease burden attributable to physical inactivity. For reducing alcohol misuse, a package of eight individual- and population-targeted interventions could avert a third of disease burden attributable to hazardous and heavy levels of drinking. Although the current practice of random breath testing is cost-effective, if the expenditure on random breath testing had been distributed to more cost-effective interventions, around ten times the improvement in population health could have been achieved. The individually-targeted interventions for body mass, fruits and vegetables and salt intake are not cost-effective. Providing incentives for food industry to reduce salt in processed foods, on the other hand, is far more effective in improving population health and can lead to cost-saving for the health sector in the long term. if (moderate) reductions in salt were made mandatory for food manufacturers, around 20 times the health gains achieved by the current voluntary program could be achieved. Overall, eight interventions are potentially cost-saving for the health sector: voluntary and mandatory limits on salt in processed foods; mass media- and pedometer-based community campaigns to promote physical activity; a community program to promote fruits and vegetables; and volumetric taxation, advertising bans and an increase of the minimum legal drinking age to 21 years to address alcohol misuse. A further 12 interventions for reducing alcohol misuse, and promoting physical activity and fruit and vegetable consumption, are under a $50,000 per DALY threshold of costeffectiveness, and are also recommended for health sector investment. Implications The integration of a proportional multi-state life table model with PIF function in this research has proved to have a number of advantages over previous modelling methods. The PIF function enables better simulation of the true continuous distribution of risk in the population, and facilitates analysis of population-targeted interventions that shift the whole distribution of risk. It also substantially simplifies the integration of multiple risk factors into the one model, which was previously constrained by the need to create separate states for every risk factor category (e.g. active and inactive) and risk factor categories in combination (e.g. obese and active, obese and inactive, etc.). This not only makes for easier and more accurate analyses of interventions targeting multiple risk factors, but enables evaluation of packages of many different risk factor interventions. Further investment in preventive interventions is highly recommended. The population-targeted approaches hold most promise for improving population health. Although there is potential for opposition from industry stakeholders and public concern around Government paternalism, these interventions have most potential to generate cost-savings for the health sector in the long-term. Given the weaker evidence around effectiveness of these interventions, however, it is recommended that programs are implemented with sufficient funding for monitoring and evaluation of outcomes.