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Will the Daily Consumption of Commercially Available High-Protein Pasta and Cereal, in Comparison to Traditional Gluten-Free Pasta and Cereal, Favorably Impact Weight Loss and Satiety in Adults Adhering to Calorie Restricted Diets?January 2015 (has links)
abstract: ABSTRACT
Objective: This research examined the effectiveness of a weight loss diet incorporating high protein pasta and breakfast cereal products as compared to a weight loss diet using conventional versions of gluten-free pasta and breakfast cereal.
Design: In a 6-week parallel-arm food trial (representing the first phase of a 12-week cross-over trial), 26 overweight and obese (Mean BMI 43.1 ± 12.4 kg/m²) participants, free of related comorbidities, were randomly assigned to the Zone diet (~29% energy intake from protein) or a control diet (~9% energy from protein). Participants were included in the trial if they satisfied the criteria for elevated risk for metabolic syndrome (top half of the TG/HDL ratios of all who were tested). Participants were instructed to eat prepared meals (total of 7 cereal packets and 14 pasta meals weekly) that included patented food technologies for the Zone diet and commercially available gluten-free rice pasta and a conventional name brand boxed cereal for the control diet. Body composition was measured with a bioelectrical impedance scale at weeks 1, and 6. Food records and diet adherence were recorded daily by the participants.
Results: Both the Zone and control diets resulted in significant weight loss (-2.9 ± 3.1 kg vs. -2.7 ± 2.6 kg respectively) over time (p = 0.03) but not between groups (p = 0.96). Although not statistically significant, the Zone diet appears to have influenced more weight loss at trial weeks 3, 4, and 5 (p = 0.46) than the control diet. The change in FFM was significant (p = 0.02) between the Zone and control groups (1.4 ± 3.6 kg vs. -0.6 ± 1.5 kg respectively) at week-6. Study adherence did not differ significantly between diet groups (p = 0.53).
Conclusions: Energy-restricted diets are effective for short-term weight loss and high protein intake appears to promote protein sparing and preservation of FFM during weight loss. The macronutrient profile of the diet does not appear to influence calorie intake, but it does appear to influence the quality of weight loss. Other measures of body composition and overall health outcomes should be examined by future studies to appropriately identify the potential health effects between these diet types. / Dissertation/Thesis / Masters Thesis Nutrition 2015
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Studies on crystallization of lactose in permeates and the use of modified milk protein concentrate in high-protein dairy beveragesPandalaneni, Karthik January 1900 (has links)
Doctor of Philosophy / Food Science Institute / Jayendra K. Amamcharla / Lactose is commercially produced from whey, whey permeate, or milk permeate as α-lactose monohydrate in crystalline form. Focused Beam Reflectance Measurement (FBRM) as a potential tool for in situ monitoring of lactose crystallization at concentrations relevant to the dairy industry was evaluated. Applicability of FBRM at supersaturated lactose concentrations 50%, 55%, and 60% (w/w) was reported in comparison with Brix values obtained from a Refractometer during isothermal crystallization at temperatures 20ºC and 30ºC. FBRM technique was shown to be a valuable tool for monitoring chord length distributions during lactose crystallization. In a different study, the influence of cooling rate during crystallization of lactose in concentrated permeates was studied. Three cooling rates accounting for approximately 17, 11, and 9 h were applied during lactose crystallization to evaluate the lactose crystal yield and quality of lactose crystals. There was no significant difference (P>0.05) found in lactose crystal yield, mean particle size obtained at the end of crystallization. This study suggested that increasing the cooling rate during lactose crystallization within the range explained in this study can save approximately 8 h of crystallization time. These studies evaluated FBRM as a potential tool to monitor lactose crystal chord lengths and counts. Also, process improvements were suggested to increase the productivity of lactose crystallization process by reducing the crystallization time.
In chapters 5 and 6, calcium-reduced milk protein concentrates (MPCs) were used as an ingredient to improve the stability of high-protein dairy beverages. Heat stability increased significantly (P>0.05) in 8% protein solutions made from 20% calcium-reduced MPC. A significant increase in heat stability was observed in beverages formulated with 20% calcium-reduced MPC in the absence of chelating agent. In another study, it was evident that the dairy beverage formulation with 20% calcium-reduced MPC showed no sedimentation and age gelation indicating an improved storage stability. These studies confirmed that 20% calcium reduced MPC contributed towards improved heat stability and storage stability of the high-protein beverages.
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Use of Extrusion Technology and Fat Replacers to Produce High Protein, Low Fat CheeseDubey, Amrita 01 May 2011 (has links)
This study investigated the use of extrusion technology and fat replacers to produce high protein, low fat Cheddar cheese. In chapter 3, four different fat replacers were tested at the highest concentration level of each, as recommended by the manufacturers for low fat cheese, to investigate the change in cheese texture and optimize extruder conditions. In addition, the press time/pressure combinations of the extruded cheeses were optimized. The fat replacers and extruder conditions that were effective in improving the texture of low fat cheese were then used in chapter 4.
In chapter 4, three fat replacers were used at three different concentrations (lowest, middle and highest) as recommended by the manufacturers for replacing fat in cheese. The fat replacers were microcrystalline cellulose (MCC 1) (0.125%, 1.06% and 2%), whey protein concentrate (WPC 2) (0.50%, 0.75% and 1%) and whey protein concentrate (WPC 1) (0.40%, 2.20% and 4%). These fat replacers were effective in improving the texture of low fat cheese as determined from the results of chapter 3. The extruded cheese samples with and without fat replacers were analyzed for texture at three different time periods (1 day, 1 week, and 1 month). None of the fat replacers used were effective in improving the texture of low fat cheese significantly.
Since none of the treatments statistically improved the texture of low fat cheese, in the next part of the study, extrusion alone and WPC 1 at the middle concentration were then used to produce low fat cheese with high protein content by blending low moisture aged Cheddar cheese and nonfat cheese. Extrusion of cheese blends with or without fat replacer yielded cheese with high protein level. It was concluded from the study that the fat replacers we used were not effective in improving the texture but extrusion of aged Cheddar cheese with nonfat cheese can yield high protein cheese.
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Exposition périnatale à un régime maternel de quantité et de qualité variables en protéines chez le rat : préférences alimentaires et phénotype de la descendance du sevrage à l’âge adulte / Perinatal exposure to a maternal diet varying in quantity and quality of protein in rat : food preferences and phenotype of offspring from weaning to adulthoodCarlin, Gabrielle 19 April 2019 (has links)
L’exposition au régime maternel durant la période périnatale, induit des processus d’empreintes orientant à long terme le phénotype et la santé des individus. De plus, les orientations alimentaires, telles que celles concernant les protéines, évoluent quantitativement et qualitativement. Ces deux constats, encouragent la communauté scientifique à s’interroger sur les conséquences de ces variations de consommation en protéines sur les générations futures. Ce projet de thèse vise à évaluer chez la descendance femelle rat, les effets d’une alimentation maternelle variant par la teneur (riche versus normal) et la qualité (sources animales versus végétales) en protéines sur la modification des préférences alimentaires et sur les risques métaboliques.Deux études ont été réalisées chez le rat. Une première étude a évalué l’impact de l’excès de protéines à travers un régime hyperprotéique (HP) à base de protéines de lait pendant la gestation. Une seconde étude a évalué les effets d’un régime HP de source protéique spécifique (lait, pois ou dinde) pendant la gestation et d’un régime de source protéique spécifique (lait, pois ou dinde) pendant l’allaitement. Une fois sevrés et jusqu’à l’âge adulte (étude 1 : 15 semaines ; étude 2 : 10 semaines), les ratons femelles ont été soumis à des modèles de « dietary self-selection » (DSS) leur laissant la possibilité de choisir la composition en macronutriments, le niveau de consommation alimentaire et la source protéique (étude 2 uniquement). Indépendamment du régime maternel, ces deux études ont montré que lorsque les sources en macronutriments étaient séparées dans le modèle DSS, les ratons présentaient une hyperphagie liée à une consommation accrue de lipides au détriment des glucides.De plus, les résultats de la seconde étude ont montré que les ratons n’orientaient pas spécifiquement leur consommation de protéines vers la source protéique à laquelle ils avaient été exposés via le régime maternel périnatal. En revanche, les deux études ont montré que la consommation d’un régime HP pendant la gestation, quelle que soit la qualité des protéines le composant, induisait une augmentation de l’adiposité chez la descendance femelle adulte. Cette augmentation était majorée lorsque la descendance avait été soumise au régime de choix (DSS), leur permettant d’augmenter leur consommation de lipides au détriment des glucides.En conclusion, l’exposition périnatale à un régime HP de qualité variable en protéines augmente la sensibilité au surpoids chez la descendance femelle adulte rat. Nous avons évalué les relations entre ces données et : la sensibilité des voies centrales du contrôle de la prise alimentaire et de la récompense, la sensibilité des voies de contrôle du métabolisme énergétique périphérique et la composition et l’activité du microbiote de l’intestin.Ces travaux apportent un grand nombre de nouvelles données indiquant clairement qu’une alimentation équilibrée en quantité et en qualité de protéines pendant la grossesse, à travers le ratio protéines/glucides et le profil en acides aminés, pourrait jouer un rôle clé sur des paramètres phénotypiques de la descendance notamment lorsqu’elle est soumise à des choix alimentaires augmentés. / Abstract : Perinatal exposure to maternal diet induces programming processes of later individual phenotype and health. Additionally, food orientations like for protein, change in terms of quantity and quality. These observations enhance scientific community to evaluate consequences of protein consumption changes on future generations.This thesis project aims to determine the consequences of modifying protein quantity and quality in maternal diets on food preferences and metabolic risks in female rat offspring.Two studies were conducted in rats. The first study evaluated the impact of protein excess in the maternal diet during gestation, through a high-protein (HP) diet composed with cow milk protein. The second study evaluated effects of (i) a HP diet composed with different protein sources (cow milk, pea, or turkey) during gestation and (ii) these different protein sources (cow milk, pea, or turkey-derived) during lactation. From weaning to adulthood (study 1: 15 weeks after birth; study 2; 10 weeks after birth), female pups were subjected to “dietary self-selection” (DSS), which allowed them to choose their own macronutrient compositions, level of food intake and protein sources (second study only).Regardless of the maternal diet, these two studies showed that when DSS was composed with separate macronutrients, rats exhibited overfeeding and increased lipid intake coupled with a decreased carbohydrate intake. Moreover, the results of the second study indicated that rats did not orient their protein intake towards the maternal protein source to which they were exposed during perinatal period. Nevertheless, the two studies showed that the maternal HP diet during gestation caused an increased adiposity in female adult offspring, regardless of the maternal protein source. This increase was stronger when offspring were subjected to DSS condition, which allowed them to increase lipid intake and decrease carbohydrate intake.In conclusion, perinatal exposure to a HP diet varying in protein quantity and quality increases the risk of becoming overweight in female rat adult offspring. We assess the relationship between these data and the the sensitivity of central pathways of food intake and reward control, the sensitivity of energetic and peripheral metabolic pathways, and the gut microbiota composition and activity.This work provides new data indicating that a balanced diet in protein quantity and quality during gestation, through a protein/carbohydrate ratio and amino acid profile, could play a key role on offspring phenotypic parameters, especially when submitted to increased dietary options.
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Effect of Dietary Protein Intake on Body Composition Changes During Intense Training in an Energy DeficitLongland, Thomas M. 27 May 2015 (has links)
<p>What a ride it has been. The ups and downs of the McMaster graduate program has been a sweet one. It has been a pleasure working with the Exercise Metabolism Research Group for the past 2 years, and I will miss being around the work that goes on in the trenches around the lab. I have leaned on many people for all types of guidance through this journey, and would like to thank everyone for their unprecedented support. I have grown as a person and student and will use everything I have learned at this fine establishment I’m sure at one point or another along the great path of life. I must thank my amazing parents, family, friends and of coarse Ashley for putting up with my work ethic throughout my studies; the long days that I would go missing. Without their support none of this would have been possible. I have to specially mention Melanie Wolfe for recommending myself, and ultimately Stu Phillips for presenting this opportunity that is coming to a close. I have had great senior support from Cam Mitchell, Tyler Churchward-Venne, Todd Prior and Michaela Devries in putting this document together, and would not be submitting this without their selfless assistance. It’s been a journey getting to this point, but I wouldn’t change it for the world, to the next chapter in life, cheers and God Bless.</p> / <p>Higher dietary protein intake, greater than the Recommended Dietary Allowance (RDA; 0.8 g protein/kg/d), coupled with resistive exercise has been shown to aid in preservation of muscle mass during hypocaloric diet-induced weight loss. We examined the impact of dietary protein supplementation at two levels (1.2 and 2.4 g/kg/d) on body composition during a 4wk hypocaloric dietary intervention that included 6d/wk of high intensity resistance exercise and interval training. In a single blind study, forty young men consumed 33±1.1 kcal/LBM (~40% reduction versus estimated energy requirements), and were randomly assigned to a group that consumed either 1.2g/kg/d protein or 2.4g/kg/d. Body composition was determined using DXA, Bod Pod, and Bio-impedance pre- and post-intervention to derive a 4-compartment model for body composition. Both groups retained lean mass (LM), but retention was greater in the higher protein group (p</p> / Master of Science (MSc)
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Effect of a Low-Carbohydrate, High-Protein Diet on Bone Mineral Density, Biomarkers of Bone Turnover, and Calcium Metabolism in Healthy Pre-Menopausal FemalesColeman, Mary Dean 15 September 2004 (has links)
Low-carbohydrate, high-protein (LCHP) diets have been shown to induce weight loss and beneficial changes in blood lipids that suggest cardiovascular disease risk reduction; however, LCHP diets have not been adequately investigated for health effects on the skeleton. A randomized trial to determine the effects of a LCHP diet on bone mineral status, biomarkers of bone turnover, indicators of acid-base balance, calcium homeostasis and fasting lipids in healthy pre-menopausal women was conducted. Women, aged 32 - 45 y, with a body mass index between 25-41 kg/m2 were randomized into one of two diet groups: LCHP (n = 13) or high-carbohydrate, low-fat (HCLF) (n = 12). Anthropometric (body weight, lean mass, fat mass) and bone mineral density (BMD) and content (BMC) measures and markers of lipid metabolism were taken at weeks 0, 6, and 12. Measures of acid-base balance, protein metabolism, and calcium homeostasis were conducted at weeks 0, 1-4, 6, and 12. Serum osteocalcin was analyzed at weeks 0, 1, 2, 6, and 12, while urinary NTx was analyzed at weeks 0, 1 and 2. Weight loss was significant at the end of 12 weeks in both diet groups (P < 0.05) but there was no Diet x Time interaction. Total proximal femur BMD was lower in the LCHP group (P < 0.05) compared to the HCLF group by week 12. Femoral neck BMC decreased in the LCHP diet group (P < 0.05), whereas total forearm BMC increased (P < 0.05) in the HCLF diet group by week 12 of the study. Serum osteocalcin showed significant main effects of diet (P < 0.05) and time (P < 0.0001), but a Diet x Time interaction was not observed. Urinary NTx exhibited no main diet effect, time effect or Diet x Time interaction at weeks 1 or 2. Urinary pH was lower in the LCHP group compared to the HCLF group throughout the study (P < 0.0001). Urinary calcium excretion was higher in the LCHP group and lower in the HCLF group (P < 0.0001) compared to baseline values at all intervals of the study. Urinary phosphorus excretion exhibited a significant diet effect (P < 0.001) and time effect (P < 0.002), while no Diet x Time interaction was observed. Total cholesterol, high-density and low-density lipoprotein cholesterol, and triacylglycerol concentrations did not differ between diets during the study. In conclusion, a LCHP diet appears to stimulate bone loss, while a HCLF diet appears to attenuate bone loss in healthy pre-menopausal women undergoing 12 weeks of weight loss. / Ph. D.
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High protein dietary patterns and Type 2 diabetes.Pearce, Karma Louise January 2008 (has links)
By the year 2025, it is anticipated that over 300 million individuals world wide will have type 2 diabetes, with a projected increase from 84 to 288 million (170%) in developing countries and from 51 to 72 million (42%) in developed countries. Diabetes leads to a markedly increased risk of heart disease and renal failure and to expensive and debilitating retinopathy and neuropathy. Cognitive decline is also increased. As there is accumulating evidence of the beneficial effects of moderate carbohydrate, low fat dietary patterns compared to high carbohydrate diets, this thesis will focus on the effects of moderate carbohydrate high protein dietary patterns (total carbohydrate: protein: fat ratio of 40%:34%:26%) on glycemic control, risk factors for macrovascular disease and cognitive function. Information on two key areas in type 2 diabetes will be presented, 1. Acute effects of dietary patterns, moderately carbohydrate restricted and high in protein on glucose levels assessed using continuous glucose monitoring systems (CGMS) with verification of these results through a small repeat study. 2. Chronic effects of energy restricted dietary patterns, moderately carbohydrate restricted and high in protein on glucose levels, HbA1c, cognitive function, cardiovascular disease (CVD) risk markers and renal function. In the acute study, we recruited 23 subjects with type 2 diabetes. The participants were randomized to each of 4, 3-day interventions in a cross over design with a 4 day wash out period in which the carbohydrates were distributed differently at each meal; carbohydrates evenly distributed across the day, or carbohydrates loaded at breakfast, lunch or dinner. Glucose levels were continuously measured using CGMS. Outcomes were assessed by postprandial peak glucose (Gmax), time spent above 12 mmol/L (T>12) and total area under the glucose curve (AUC20). The intervention showed that an even distribution of carbohydrates did not optimise blood glucose control, whereas carbohydrates loaded at the lunch time meal provided the most favourable postprandial profile. To verify these results we conducted a repeat study. Six of the previous participants accepted the invitation to return and complete the even distribution arm of the study after a 20 week time lag. The intervention showed that although HbA1c, fasting blood glucose (FBG), AUC, exercise and ambient temperature remained constant there was a significant effect of change in sunlight hours on Gmax, suggesting an effect of sunlight. To assess the chronic effects of energy restricted dietary patterns on the determinants of HbA1c, cognitive function, CVD risk markers and renal function under conditions of weight loss, we recruited 82 participants with type 2 diabetes. These participants were randomised to one of two high protein energy restricted dietary patterns that differed in cholesterol content, for a 12 week period, in a parallel design. A sub group of these participants completed cognitive function testing with (n=34) or without (n=17) CGMS at baseline and at 8 weeks. After 8 weeks of the intervention the determinants of HbA1c under conditions of energy restriction were evaluated. The intervention showed the change in FBG accounted for most of the variance in change in HbA1c, but % energy reduction also contributed independently of FBG. Both energy restricted high protein diets equally improved glycemic control, particularly T>12, AUC, HbA1c and FBG. Fifty one participants completed cognitive testing to evaluate the effect of weight loss and blood glucose control on cognition. Cognitive function was not altered by time, diet, baseline lipid levels. Working memory was predicted by FBG. Short term memory was predicted by FBG, Gmax and AUC24. Sixty five participants completed 12 weeks of the intervention to assess CVD risk markers and renal function. Renal function was maintained and CV markers improved on both dietary patterns, with greatest improvement in HDL-C observed in the group consuming a high protein, energy restricted dietary pattern, high in dietary cholesterol. In conclusion, in the context of a high protein, carbohydrate restricted dietary pattern, cognitive function and renal function did not change, while glycemia and CV risk profiles improved with weight loss over the short term. Under conditions of energy balance diurnal glucose profiles were optimal when the carbohydrates were loaded in the lunch meal. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342253 / Thesis (Ph.D.) - University of Adelaide, School of Molecular and Biomedical Science, 2008
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High protein dietary patterns and Type 2 diabetes.Pearce, Karma Louise January 2008 (has links)
By the year 2025, it is anticipated that over 300 million individuals world wide will have type 2 diabetes, with a projected increase from 84 to 288 million (170%) in developing countries and from 51 to 72 million (42%) in developed countries. Diabetes leads to a markedly increased risk of heart disease and renal failure and to expensive and debilitating retinopathy and neuropathy. Cognitive decline is also increased. As there is accumulating evidence of the beneficial effects of moderate carbohydrate, low fat dietary patterns compared to high carbohydrate diets, this thesis will focus on the effects of moderate carbohydrate high protein dietary patterns (total carbohydrate: protein: fat ratio of 40%:34%:26%) on glycemic control, risk factors for macrovascular disease and cognitive function. Information on two key areas in type 2 diabetes will be presented, 1. Acute effects of dietary patterns, moderately carbohydrate restricted and high in protein on glucose levels assessed using continuous glucose monitoring systems (CGMS) with verification of these results through a small repeat study. 2. Chronic effects of energy restricted dietary patterns, moderately carbohydrate restricted and high in protein on glucose levels, HbA1c, cognitive function, cardiovascular disease (CVD) risk markers and renal function. In the acute study, we recruited 23 subjects with type 2 diabetes. The participants were randomized to each of 4, 3-day interventions in a cross over design with a 4 day wash out period in which the carbohydrates were distributed differently at each meal; carbohydrates evenly distributed across the day, or carbohydrates loaded at breakfast, lunch or dinner. Glucose levels were continuously measured using CGMS. Outcomes were assessed by postprandial peak glucose (Gmax), time spent above 12 mmol/L (T>12) and total area under the glucose curve (AUC20). The intervention showed that an even distribution of carbohydrates did not optimise blood glucose control, whereas carbohydrates loaded at the lunch time meal provided the most favourable postprandial profile. To verify these results we conducted a repeat study. Six of the previous participants accepted the invitation to return and complete the even distribution arm of the study after a 20 week time lag. The intervention showed that although HbA1c, fasting blood glucose (FBG), AUC, exercise and ambient temperature remained constant there was a significant effect of change in sunlight hours on Gmax, suggesting an effect of sunlight. To assess the chronic effects of energy restricted dietary patterns on the determinants of HbA1c, cognitive function, CVD risk markers and renal function under conditions of weight loss, we recruited 82 participants with type 2 diabetes. These participants were randomised to one of two high protein energy restricted dietary patterns that differed in cholesterol content, for a 12 week period, in a parallel design. A sub group of these participants completed cognitive function testing with (n=34) or without (n=17) CGMS at baseline and at 8 weeks. After 8 weeks of the intervention the determinants of HbA1c under conditions of energy restriction were evaluated. The intervention showed the change in FBG accounted for most of the variance in change in HbA1c, but % energy reduction also contributed independently of FBG. Both energy restricted high protein diets equally improved glycemic control, particularly T>12, AUC, HbA1c and FBG. Fifty one participants completed cognitive testing to evaluate the effect of weight loss and blood glucose control on cognition. Cognitive function was not altered by time, diet, baseline lipid levels. Working memory was predicted by FBG. Short term memory was predicted by FBG, Gmax and AUC24. Sixty five participants completed 12 weeks of the intervention to assess CVD risk markers and renal function. Renal function was maintained and CV markers improved on both dietary patterns, with greatest improvement in HDL-C observed in the group consuming a high protein, energy restricted dietary pattern, high in dietary cholesterol. In conclusion, in the context of a high protein, carbohydrate restricted dietary pattern, cognitive function and renal function did not change, while glycemia and CV risk profiles improved with weight loss over the short term. Under conditions of energy balance diurnal glucose profiles were optimal when the carbohydrates were loaded in the lunch meal. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1342253 / Thesis (Ph.D.) - University of Adelaide, School of Molecular and Biomedical Science, 2008
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Calories vs. composition : the effects of dietary alterations on anthropometric measures and biochemical parameters in overweight women / Effects of dietary alterations on anthropometric measures and biochemical parameters in overweight womenRiggs, Amy Jo January 2002 (has links)
TITLE: Calories vs. Composition: The effect on dietary alterations on anthropometric measures and biochemical parameters in overweight women.LEARNING OUTCOME: To determine if a high-protein, low-carbohydrate, ad-libitum diet is more effective than an energy-restricted diet in promoting weight loss and improving blood lipid and insulin levels.ABSTRACT TEXT: Thirty overweight/obese (BMI: 25-35kg/m2), premenopausal women were matched for Body Mass Index (BMI) and randomly assigned to one of the two diets: (1) High Protein (HP) (30-40% protein, 40-55% fat, 10-20% CHO); (2) Energy Restricted (ER) (1200kcal/d, 20-25% fat, 15-20% protein, 55-60% CHO). Subjects were given weekly menus matching their assigned macronutrient and/or energy requirements to aid in meal planning and dietary compliance. Baseline and post-diet measures included height, weight, body composition, blood lipids (total cholesterol (TC), HDL, LDL< and triglycerides (TG)], and plasma insulin levels. There were no significant differences found among the two groups in any of the above-listed variables prior to the study. Twenty-three women completed the 6-week study (HP=11, ER= 12). Compliance to the diets was adequate as indicated by weekly 24-hour recalls and daily urinary ketone levels. Both groups lost a significant amount of weight and body fat (P<0.05), andweight and body fat losses were not significantly different between the groups. In addition, both groups experienced similar decreases in TG, TC, LDL, HDL, and insulin levels. These results indicate that a HP diet is no more effective than an ER diet in promoting favorable changes in body weight, body composition, blood lipids, and insulin levels. / Department of Family and Consumer Sciences
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Nutritional regulation of resistance to Nippostrongylus brasiliensis in the lactating ratMasuda, Aya January 2017 (has links)
Animals acquire immunity against gastrointestinal (GI) nematode infection depending on their age and continual exposure to larvae, however, expression of this acquired immunity is often penalized during pregnancy and lactating period. This is described as periparturient relaxation in immunity (PPRI), and suggested to have nutritional basis. Although dietary protein has positive effect on immunity against GI nematode infection in mammalian host, we have not fully achieved to characterise the detailed interaction between PPRI and dietary protein. Therefore, this PhD aimed to further investigate this interaction in a well-established Nippostrongylus brasiliensis re-infected lactating rat model. Feeding high protein diet (HP) as opposed to low protein diet (LP) during pregnancy was necessary in maintaining sufficient maternal performances and systemic immune response (Chapter 2 and 3). Accumulation of host’s body protein reserve during pregnancy was significantly higher in HP fed animals compared to LP fed counterparts, which led to improvement in both maternal performances and immunity during the early stage of lactation. However, as lactation period progressed and re-infection of N. brasiliensis took place, importance of current dietary status, rather than the accumulated protein reserve, became evident for maternal performances and immunity. Indeed, animals fed HP during lactation showed significantly heavier pup weight compared to LP fed animals; HP animals showed higher serum immunoglobulin levels and reduced worm burden compared to LP. N. brasiliensis, however, goes through systemic migration, entering host’s skin and migrating to lung parenchyma through blood vessels before reaching the intestine. In Chapter 4, a detailed lung pathology study following N. brasiliensis infection was performed to generate data on the effects of the nematode in the lung of the rat host as such data were scarce. Rat host showed similar lung pathology to that of mice; up-regulation of genes related to type 2 immunity and development of emphysema-like pathology were observed following N. brasiliensis re-infection. In Chapter 5, the effect of dietary protein supplementation on lung and intestinal histology and gene expression analysis was investigated. It was shown that HP fed animals showed higher expression of genes related to type 2 immunity compared to LP in the lung. This effect of protein supplementation in the lung may have contributed to fewer worm burdens in HP fed rats compared to LP in the intestine. Dietary protein supplementation significantly affected the expression of genes related to goblet cells; it resulted in up-regulation of the expression of Retnlb and down-regulation of Agr2 and Tff3 in HP fed animals compared to LP. It is evident that dietary protein is modulating intestinal immunity, and this may be targeted towards specific pathways. In addition, the effect of dietary protein supplementation on immune cell populations of secondary lymphoid organs was analysed. Marked increase in the percentage of macrophage in the spleen and T cell in the mesenteric lymph node was observed following protein supplementation, highlighting the importance of dietary protein on systemic immunity during the parasite infection. These results demonstrate that dietary protein supplementation is effective for improving both maternal performances and immune responses, not only at the intestinal phase but also at the migrating phase, when animal is undergoing PPRI during N. brasiliensis infection. Such information is expected to define strategic utilisation of nutrient supply and to result in development of sustainable parasite control strategies in mammals.
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