Thesis--PlanA (M.S.)--University of Wisconsin--Stout, 2003. / Includes bibliographical references.

The objectives of the present study were to examine the effects of dietary fat type and level of energy intake on hypothalamic leptin binding affinity and membrane fatty acid composition, circulating leptin levels, and body weight homeostasis in rats. Animals were fed diets containing tallow, safflower oil, or menhaden oil (20% wt/wt) for 10 wks, ad libitum or at 60% of ad libitum intakes. Specific leptin binding could not be detected in hypothalamic membrane homogenates; hypothalamic leptin levels were unaffected by diet or energy intake. Levels of tracer exceeding assay reference values were found in homogenates, suggesting intra-membrane binding. Excess tracer levels were weakly associated (p < 0.07) with the sum of hypothalamic phospholipid monounsaturates. Restriction lowered weight gain and food intakes (p < 0.0001 for both). In hypothalamic phospholipids, energy restriction lowered levels of 18:3(n-3) and increased levels of 20:1(n-9), 20:4(n-6), and 22:4(n-6) (p < 0.05, p < 0.02, p < 0.05, and p < 0.04, respectively). Fat type and energy level interactively affected hypothalamic levels of 20:4(n-6), 22:5(n-3) and 22:6(n-3) (p < 0.05, p < 0.006, and p < 0.05, respectively). Restriction lowered circulating leptin levels (p < 0.0001); overall plasma leptin levels were marginally associated (p < 0.07) with hypothalamic 16:0 concentrations. The results of the study support previous findings suggesting that leptin binding at the level of the hypothalamic membrane may not be detectable. The results also support the lack of a dietary fat effect on plasma leptin levels and levels of certain hypothalamic fatty acids, such as 20:4(n-6), 22:4(n-6), and 22:5(n-3), with energy restriction. The findings of the study suggest a link between increased membrane fluidity, increased binding affinity, and lower circulating leptin levels, promoting the possibility that the biological actions of leptin can be controlled through dietary effects on

No description available.

In a cross-sectional study we examined Iipoprotein composition and CETP mass in 15 sedentary and 12 exercising, healthy male volunteers, aged between 17-35 years. The exercising group were defined as individuals participating in at least five weekly 45 minute exercise sessions of an aerobic nature (60-85% estimated maximal oxygen uptake). The sedentary subjects were only irregularly engaged in bouts of physical activity, not more than 45 minutes per week. Seasonal data were collected: one data collection in the fall and one in the spring. A 20 day food and exercise journal was maintained during each season's data collection period. Blood lipids were measured on two and anthropometric and aerobic capacity testing were performed on 1 occasion during each season. Statistical analyses consisted of a two way ANOVA (exercise and season) to control for seasonal effects on blood lipids and Iipoprotein levels. Pearson product moment correlations were calculated between those variables that showed significant seasonal or level of activity changes. Exercising males consumed significantly greater amounts of energy (p<O.OOI), carbohydrates (p<O.OOOI), protein (p<O.OOOI), and dietary fibre (p<O.OOOI) than sedentary males; sedentary males however, consumed significantly greater amounts of alcohol than exercising males. Exercising males had significantly higher aerobic capacities and degrees of mesomorphy than sedentary subjects and exhibited significantly lower apo AI values. No differences were noted between the 2 groups in BMI, % body fat, other plasma lipids or CETP mass. In summary, regular physical activity in young, healthy male subjects was associated with increased energy and carbohydrate intake and improved aerobic capacity as compared to sedentary subjects. Moderate differences in physical activity were not however associated with alterations in plasma Iipoprotein composition or CETP concentration.

In a cross-sectional study we examined lipoprotein composition and CETP mass in 15 sedentary and 12 exercising, healthy male volunteers, aged between 17-35 years. The exercising group were defined as individuals participating in at least five weekly 45 minute exercise sessions of an aerobic nature (60-85% estimated maximal oxygen uptake). The sedentary subjects were only irregularly engaged in bouts of physical activity, not more than 45 minutes per week. Seasonal data were collected: one data collection in the fall and one in the spring. A 20 day food and exercise journal was maintained during each season's data collection period. Blood lipids were measured on two and anthropometric and aerobic capacity testing were performed on 1 occasion during each season. Statistical analyses consisted of a two way ANOVA (exercise and season) to control for seasonal effects on blood lipids and lipoprotein levels. Pearson product moment correlations were calculated between those variables that showed significant seasonal or level of activity changes. Exercising males consumed significantly greater amounts of energy (p $<$ 0.001), carbohydrates (p $<$ 0.0001), protein (p $<$ 0.0001), and dietary fibre (p $<$ 0.0001) than sedentary males; sedentary males however, consumed significantly greater amounts of alcohol than exercising males. Exercising males had significantly higher aerobic capacities and degrees of mesomorphy than sedentary subjects and exhibited significantly lower apo AI values. No differences were noted between the 2 groups in BMI, % body fat, other plasma lipids or CETP mass. In summary, regular physical activity in young, healthy male subjects was associated with increased energy and carbohydrate intake and improved aerobic capacity as compared to sedentary subjects. Moderate differences in physical activity were not however associated with alterations in plasma lipoprotein composition or CETP concentration.

Thesis (M.Ag.Sc.)--University of Adelaide, Dept. of Animal Sciences, 1989. / Includes bibliographical references (leaves 196-220).

No description available.

The objective of this study was to compare the effects on eating behavior, lipids, lipoproteins, lipid peroxidation, and glycemic control in women with type 2 diabetes of a high-monounsaturated fat diet (HM) compared to a high-carbohydrate diet (HC). In an outpatient feeding study, ten hypertriglyceridemic postmenopausal type 2 diabetic women alternately for six weeks consumed the HM and HC diets. On the HM diet, 45% of total calories were consumed as carbohydrate and 40% as fat (27% monounsaturated) compared to 55% carbohydrate and 30% fat (10% monounsaturated) in the HC diet. At the beginning and end of each diet phase, total lipids, lipoproteins, lipid peroxidation, and glycemic variables were measured. For 8 days in each diet phase eating pattern frequency, palatability of foods, hunger and fullness were assessed. At the end of each diet phase, taste testing to determine preference for fat was conducted. Total cholesterol was significantly decreased on the HC diet. Serum triglyceride, very low density lipoprotein (VLDL) triglyceride and cholesterol, and apolipoproteins A-1 and B were not significantly different on the two diets. When comparing initial to final values, both diets lowered LDL-C; however, the change was greater on the HM diet. Lipid peroxidation variables improved when the HM diet was consumed. Glycemic variables improved on both diets. No significant differences between total number of eating episodes on the HM and HC diet phases were found. Both diets were rated as highly palatable. Hunger and fullness ratings varied within and between subjects. However, fullness was more commonly experienced than hunger on both HM and the HC diet. Preference for fat was not found at the end ofHM or HC diets. However, subjects differed significantly in ratings for liking of foods that were salty, sour, and bitter when compared to nondiabetic women. Consumption of the HM and HC diets did not result in deterioration of lipid status. The HM diet by virtue of less oxidation of the LDL particle and improvement of glycemic control provides an important advantage over the HC diet. A description of eating behavior of women with type 2 diabetes emerged. / Graduation date: 2000

While replacement of dietary saturated fat with unsaturated fat has been advocated to reduce cardiovascular disease risk, diets high in polyunsaturated fatty acids (PUFA) could increase low density lipoprotein (LDL) susceptibility to oxidation, potentially contributing to the pathology of atherosclerosis. To assess in vivo lipid peroxidation and susceptibility, of LDL surface and core lipids to ex vivo oxidation, in women consuming increased amounts of specific unsaturated fatty acids, 15 postmenopausal women took daily supplements of sunflower oil providing 12.3 g/day of oleate, safflower oil providing 10.5 g/day of linoleate, and fish oil providing 2.0 g/day of eicosapentaenoate (EPA) and 1.4 g/day of docosahexaenoate (DHA) during a crossover trial. Plasma F₂-isoprostanes (F₂-isoP), malondialdehyde (MDA), and thiobarbituric acid reacting substances (TEARS) were measured to assess lipid peroxidation in vivo. Ex vivo oxidation of LDL was monitored by measuring the formation of phosphatidylcholine hydroperoxides (PCOOH) and cholesteryl linoleate hydroperoxides (CE18:200H) during coppermediated oxidation. Plasma free F₂-isoP and MDA concentrations were lower after EPA/DHA supplementation than after oleate (P = 0.001, F₂-isoP and 0.02, MDA) and linoleate supplementation (P = 0.04 for both F₂-isoP and MDA). However, plasma TBARS concentrations were higher after EPA/DHA than after oleate (P = 0.001) and linoleate supplementation (P = 0.0004). During LDL oxidation, the lag phase for PCOOH formation was shorter in EPA/DHA- than oleate- (P = 0.0001) and linoleate-enriched LDL (P = 0.002), while the lag phase for CE18:200H was shorter in EPA/DHA- than oleate- (P = 0.01) but not linoleate-enriched LDL. The maximal rate of PCOOH formation was lower in EPA/ DHA- than linoleate- (P = 0.007) but not oleate-enriched LDL, while the maximal rate of CE18:200H formation was lower in EPA/DHA- than oleate- (P = 0.03) and linoleate-enriched LDL (P [less than or equal to] 0.0001). The maximal concentrations of PCOOH and CE18:200H were lower in EPA/DHA- than oleate- (P [less than or equal to] 0.05) and linoleate-enriched LDL (P [less than or equal to] 0.01). Oleate-enrichment generally decreased the oxidative susceptibility of LDL surface and core lipids, while EPA/DHA-enrichment did not increase LDL oxidative susceptibility compared to linoleate-enrichment. This study emphasizes the need for more than one relevant assay of in vivo lipid peroxidation. / Graduation date: 2000

Includes bibliographical references (leaves 196-220) Studies the growth, body composition, feed intake of grazing animals, the use of anabolic agents, fatty acid composition of ruminants fats; and, the effect of saturated fat on human health.