Currently no ideal method for the assessment of dietary intake of individuals or groups exists. All diet assessment methods have their limitations; much debate exists as to which method is best. The goal is to design an assessment tool that is comprehensive in that it reflects dietary variety but that is not too burdensome for participants. The FCM integrates an interview tool with a computerized program that quantifies food and nutrients in real time. The present study was undertaken to determine if the FCM is appropriate to use with community living older adults. This exploratory study used a mixed method approach to determine differences in recall between the FCM and three 24 HRs. Quantitative findings show significant differences between the methods in reports of energy, zinc, and calcium intakes and consumption of “other” foods. Qualitative findings show that the abstract thinking required to complete the FCM may be difficult for this population.

The work in this thesis covers the development of assays for bacterial nitrosation and nitrous oxide reductase. The use of these two assays and the nitrite reductase assay allowed a detailed study not only of the correlation between nitrite reductase and nitrosation but also between nitrous oxide reductase and nitrosation in Neisseria subflava. The three activities have been studied with various electron donors and inhibitors and also with cells grown under various conditions. Maximum activities were:- Nitrite reductase 1130 nmol/min/mg protein with lactate as electron donor, Nitrous oxide reductase 7.17 ^unol/min/mg protein with glucose as electron donor 7 and nitrosation 427 nmol/min/mg protein with ethanol as electron donor. When this work was coupled with the production of N.subflava mutants deficient in different aspects of denitrification using insertional transposon mutagenesis it provided a wealth of information regarding the correlation between denitrification and bacterial nitrosation. The strains of N.subflava isolated from the achlorhydric stomach were all able to nitrosate. The ability to nitrosate required the reduction of nitrite but nitrite reductase itself was unable to catalyse nitrosation. Reactions involving nitrous oxide, nitrous oxide reductase and dinitrogen were shown to have no involvement in bacterial nitrosation. Leaving only nitric oxide and nitric oxide reductase as possible connections between bacterial nitrosation and denitrification. With the knowledge that oxygen was required for bacterial nitrosation and the growth conditions necessary to induce bacterial nitrosation a hypothesis could be proposed to connect nitrosation activity and denitrification: Nitric oxide may accumulate following nitrite reduction and could be subsequently oxidised (by molecular oxygen) to produce dinitrogen trioxide and dinitrogen tetroxide. These two products are known to be very powerful nitrosating agents which can then react with amines, amides and ureas to produce various N-nitroso compounds. As the strains of N.subflava used in this work were gastric isolates it is plausible that these reactions producing N-nitroso compounds could occur in the stomach. This would account for the high risk from gastric cancer seen in patients whose gastric pH is close to 7 allowing bacteria to colonise the stomach.

This study took the form of three nutritional trials each examining the effects of vitamin E on various physiological, haematological and immunological functions of the rainbow trout. The preliminary study investigated the effect of feeding three experimental diets with different levels of alpha-tocopherol supplementation (0, 100 and 800 mg kgˉ¹ diet), on growth, health and various factors of the non-specific immune response. Liver alpha-tocopherol levels reflected the dietary intake of the vitamin. The fish fed the diet deficient in alpha-tocopherol showed reduced growth and increased mortality They had pale enlarged livers, their hepatosomatic indices and erythrocyte fragility was significantly higher than both the supplemented groups and haematocrit, total serum protein, globulin and complement activity were all significantly lower. No differences were observed between the tissues of the liver, spleen, kidney and heart of the three groups, however the gills structure of the fish fed the diet deficient in alpha-tocopherol showed marked deterioration. The aim of the second trial was to evaluate the effect of feeding different dietary levels of vitamin E (20, 100, 500 mg kgˉ¹ diet) in conjunction with different qualities of oil (fresh or oxidised). In addition to growth and haematological factors, various parameters of the non specific immune response were again evaluated to assess if the feeding of oxidised oil had any effect on these parameters and if the level of vitamin E in the diet had any modulating effect on any differences induced. Fish fed diets containing the lowest level of vitamin E and those fish fed the intermediate level but prepared with oxidised oil, showed classic vitamin E deficiency symptoms, similar to those seen in the preliminary trial and reduced growth and increased mortalities compared to the other groups. Levels of complement activity, were compromised both by low levels of vitamin E and oxidised oil. This suggested that oxidation of the oil content of fish diets increased the requirement for vitamin E and that a high level of vitamin E supplementation was able to compensate to some extent for the deleterious effects induced by the rancid oil. The third trial investigated the effects of different dietary levels of vitamin E (50, 150 and 750 mg kgˉ¹ diet) and immunisation, on antibody responses and mortalities following challenge with Yersinia ruckeri. In addition the effects of diet and immunisation on serum complement activity and levels were measured using three different assay techniques, two based on standard assays and a novel assay, especially developed for this trial, based on an enzyme linked immunosorbent assay (ELISA) technique. This trial, however, did not present any significant results and no correlation between, the level vitamin E supplementation in the diet and antibody response, resistance to Y. ruckeri infection in rainbow trout, could be established. The studies showed that rainbow trout fed diets deficient in vitamin E were immunologically compromised and showed reduced growth and increased mortalities. There appeared to be a definite trend for enhancement of some immunological functions correlated with increased dietary supplementation with vitamin E but this was not always statistically significant and the benefits of dietary supplementation of vitamin E at levels above those currently

The role of the lipid-soluble antioxidant α-tocopherol (vitamin E) in the nutrition of African catfish (Clarias gariepinus Burchell) has been investigated with respect to effects on growth, certain indices of health and prevention of tissue lipid peroxidation. Although juvenile C. gariepinus were not found to show an immediate dependency on vitamin E for growth, even during rapid growth stages, a minimum requirement of α-tocopherol based on the prevention of hepatic lipid peroxidation was established at 30-40 mg α-tocopherol per kg dry diet. This is in line with published values for numerous cultured fish species. Tissue α-tocopherol accretion was found to be dependent on dietary dose of the vitamin (supplied as all-rac-α-tocopheryl acetate) and, with the exception of blood-plasma, increased tissue tocopherol status resulted in increased stability against lipid peroxidation. Assessment of iron-ascorbate induced peroxidation (as TBARS) revealed that feeding catfish with diets containing a-tocopherol at several times the currently supplemented level, improved the stability of catfish muscle and this has fillet quality implications. Similarly, heightened fillet vitamin E content resulted in lower moisture exudation from previously frozen fillets, thus demonstrating the role of a-tocopherol in the maintenance of membrane integrity. Oxidation of dietary oils and elevated ingestion of iron were found to be antagonistic of tissue vitamin E concentration. Consumption of feed containing rancid oil had marked effects on tissue fatty acid composition and these effects were modulated by increased intake of α-tocopheryl acetate. In catfish fed diets containing similar amounts of ascorbate, a higher α-tocopherol supplement marginally improved ascorbate retention indicating a possible sparing of vitamin C by vitamin E. The present work will contribute significantly to the understanding of antioxidant nutrition in this poorly researched cultured species. Furthermore, these investigations have improved and strengthened the database of knowledge accumulated within the field of nutrition of finfish.

No description available.

Nutritional aspects of size-related sex differences in the diets of free-living mink were investigated in laboratory-based feeding trials with adult farm-bred mink maintained on 'natural' diets. As preliminary studies had shown that carcase utility was virtually complete, the rations presented comprised the minced whole carcasses of wild rabbit Oryctolagus cunniculus, eel Anquilla anguilla, laboratory rats and mice, and domestic fowl. Determinations of gross composition revealed significant differences between these diets; the smaller prey types, including rodents, birds and fish, were found to have a higher ratio of Apparent Digestible Energy to Nitrogen than larger items such as rabbits, although comparisons with data presented by other workers demonstrated that the variations between species within these prey groups are as great as, or greater than, those between the diets themselves. From the results of the feeding trials, it was also apparent that such diets do not differ significantly, either in digestibility or biological value and attempts to classify particular prey items in terms of their nutritional value are, therefore, of limited application in analyses of the feeding ecology of a generalist predator. Nutrient intake was related to diet composition and varied widely between trials, although the mass-specific requirements of females were higher than those of males. Comparisons of gut morphology indicated that, in females, hypertrophy of the alimentary tract may develop in response to increased energy demands. A similar adaptation was evident in both males and females from wild populations, suggesting that the natural diets of free-living mink are generally of a lower quality than the rations fed to commercially raised animals. Feeding trials were also carried out on growing kits from 56 to 105 days post partum. Sex differences in nutrient metabolism were not significant but the growth rates of males were higher than those of females. In both sexes the growth rates of kits feeding on 'natural' diets were lower than those of animals raised on commercial rations. This effect was most pronounced in males, a finding which supports the hypothesis that the degree of sexual dimorphism in this species is dependent on the extent to which the growth potential of males is constrained by dietary regime during the early phases of development.

No description available.

Graduation date: 1951

Thesis (Ph. D.)--University of Hawaii at Manoa, 1982. / Bibliography: leaves 166-173. / Microfiche. / xii, 173 leaves, bound ill. (some col.), plates 29 cm

Research Doctorate - Doctor of Philosophy (PhD) / The prevalence of overweight and obesity in Australian children continues to rise. Without receiving treatment, many of these children will become overweight or obese adults and will develop a range of associated health problems and incur higher direct and indirect health costs compared to those who remain healthy weight. There is marked disparity between the scale of the public health issue and the evidence on how to best treat childhood obesity and which elements of dietary interventions are effective. Reviews of previous treatment studies have acknowledged methodological weaknesses which need to be addressed. Descriptions of dietary interventions, dietary intake and changes in dietary intake of children are rarely reported. This may be partly due to the lack of validated assessment tools available for use with paediatric populations. There is no question of the importance of diet in helping to reduce child obesity levels; the role of dietary treatment alone is difficult to elucidate. Consequently it is unknown what comprises an effective dietary treatment as studies to date have produced modest results and there is an ongoing need to identify which factors could improve weight related outcomes. The first aim of the studies in this thesis was to validate parental reports of young children’s fruit and vegetable intake using a child specific Australian food frequency questionnaire (FFQ) and comparing reported intakes with nutritional biomarkers. The second aim was to comprehensively describe a dietary intervention treatment program for use in a methodologically high quality obesity treatment randomised controlled trial (RCT). Thirdly, this thesis aimed to describe the parental reports of the child participants’ dietary intakes and food behaviours using the FFQ and report the parent child feeding practices. These outcome measures are reported both in the short-term (post-intervention) and the long-term (12 months post-intervention). The underlying hypothesis was that the group receiving the dietary intervention would achieve better dietary outcomes compared with a group given a physical activity treatment program only. An additional aim of the thesis was to investigate the feasibility of developing a brief dietary intake assessment tool for use in clinical and community settings by undertakinga feasibility study on the development of a diet variety score for use in assessing children’s dietary intakes. Results from the validation study of a child specific FFQ against objective nutritional biomarkers in study 1 (Chapter 3) showed that there was a moderately strong relationship between parent reported intakes of fruit and vegetables using the Australian Schools Eating Survey (ASES) FFQ with fasting plasma carotenoids. This was after adjustment for child body weight. The ASES FFQ was a useful tool for estimating the dietary intakes of fruit and vegetables in younger children via parental report. A comparative study (Chapter 4) between overweight and obese children recruited to an obesity treatment intervention and a community sample illustrated that all parents’ over-report children’s dietary intakes of foods consumed when using the ASES FFQ. Relative dietary differences were detected between the groups for the percentage energy derived from the non-core extras food group of The Australian Guide to Healthy Eating. Parents of overweight children reported more controlling methods of child feeding The detailed description of the dietary intervention used in the RCT will allow for the possibility of replication of the key elements of this approach in child obesity treatment programs. The detailed reported changes in dietary intakes resulting from the obesity treatment intervention (Chapter 5), both in the short and long-term, demonstrated that all treatment groups were effective in improving children’s dietary intakes and in reducing total energy intakes, up to one year. The comprehensive reports have facilitated the identification of effective components of dietary interventions and identified foods, lifestyle behaviours that are able to be modified and sustained by families of overweight children. In addition, it was shown that a parent’s child feeding practices can be changed and sustained secondary to an obesity treatment program. While parent child feeding practices require further investigation, this could contribute to improving the outcomes of future studies. The dietary score feasibility study (Chapter 6), found that a dietary variety score, based on the ASES FFQ was a feasible option for reporting on children’s dietary intake more universally as an indicator of whole food consumption, rather than nutrient intake. However, the score was not directly useful in the current study and the diet variety scorehas methodological weaknesses that need to be addressed before it can be used as intended. In conclusion, the findings reported in this thesis have shown the ASES FFQ is a useful tool for estimating younger children’s fruit and vegetable intake via parental report. All treatment arms of the HIKCUPS RCT were equally efficacious in improving children’s dietary intakes. This study gives unique insights to the effectiveness of a specific dietary intervention and adds to the evidence base for targeting decreases in total energy, fat, sugar, sweetened drinks and take-away foods, increasing the consumption of low fat dairy products and vegetables. It also supports using parents as the agent of lifestyle change. Furthermore, it was shown that specific child feeding domains are modifiable in the context of a targeted obesity intervention which highlights the importance of addressing broader parenting issues in the management of childhood overweight and obesity. This thesis has several novel aspects: it reports a comparative validation study of a contemporary Australian FFQ; it provides a detailed description of a dietary intervention used in the treatment of childhood obesity and the resultant dietary changes after an obesity intervention and changes to the child feeding practices of parents of obese children.