Introdução: Artrite reumatoide é uma doença inflamatória crônica associada a alterações no metabolismo proteico e energético. Objetivos: Investigar a preferência alimentar durante o desenvolvimento da inflamação crônica em ratas com artrite induzida por colágeno. Métodos: Ratas Wistar fêmeas foram alocadas em dois grupos: controle (CO, n=10) e artrite induzida por colágeno (CIA; n=11) e expostas simultaneamente a quatro diferentes dietas (padrão, hipercalórica, hiperlipidica e hiperproteica). Durante o período experimental foi observado dados clínicos da doença, consumo alimentar, peso corporal e parâmetros bioquímicos, bem como, peso muscular esquelético ao final do experimento. Os testes estatísticos realizados foram ANOVA de duas vias e test-t e nível de significância estabelecido para estes testes foi de 95%. Resultados: Os animais com artrite induzida demostram redução voluntária da ingestão total de alimento, redução do peso corporal e redução da relação sarcossomática quando comparados aos animais controles. Ainda, o grupo artrite aumentou o relativo consumo de dieta hiperproteíca, diminuiu as concentrações séricas de creatinina, triglicerídeos e glicose. Conclusão: Condições inflamatórias crônicas como a artrite reumatoide causam alterações no metabolismo energético e proteíco e estas alterações fisiológicas podem induzir a uma mudança na escolha alimentar. / Background: Rheumatoid arthritis is a chronic inflammatory disease associated with changes in energy and protein metabolism. Objective: To investigate food preferences during the development of chronic inflammation in rats with collagen-induced arthritis (CIA). Methods: Female Wistar rats were separated into two groups, control (CO, n=10) and CIA (n=11), and were simultaneously exposed to four different diets (standard, hypercaloric, hyperlipidic and hyperproteic). During the experimental period was observed clinical evidence of disease, food intake, body weight and biochemical parameters, as well as skeletal muscle weight at the end of the experiment. Statistical tests were two-away ANOVA and t-test and significance level for these tests was 95%. Results: CIA animals demonstrate voluntary reduction in total food intake, reduced body weight and reduced relative muscle weight compared to CO animals. In addition, CIA animals increased relative comsuption of high protein diet, decreased serum concentrations creatinine, triglycerides and glucose. Conclusion: Chronic inflammatory conditions such as rheumatoid arthritis cause changes in protein and energy metabolism, and these physiological alterations may induce a change in food choice.

Introdução: Artrite reumatoide é uma doença inflamatória crônica associada a alterações no metabolismo proteico e energético. Objetivos: Investigar a preferência alimentar durante o desenvolvimento da inflamação crônica em ratas com artrite induzida por colágeno. Métodos: Ratas Wistar fêmeas foram alocadas em dois grupos: controle (CO, n=10) e artrite induzida por colágeno (CIA; n=11) e expostas simultaneamente a quatro diferentes dietas (padrão, hipercalórica, hiperlipidica e hiperproteica). Durante o período experimental foi observado dados clínicos da doença, consumo alimentar, peso corporal e parâmetros bioquímicos, bem como, peso muscular esquelético ao final do experimento. Os testes estatísticos realizados foram ANOVA de duas vias e test-t e nível de significância estabelecido para estes testes foi de 95%. Resultados: Os animais com artrite induzida demostram redução voluntária da ingestão total de alimento, redução do peso corporal e redução da relação sarcossomática quando comparados aos animais controles. Ainda, o grupo artrite aumentou o relativo consumo de dieta hiperproteíca, diminuiu as concentrações séricas de creatinina, triglicerídeos e glicose. Conclusão: Condições inflamatórias crônicas como a artrite reumatoide causam alterações no metabolismo energético e proteíco e estas alterações fisiológicas podem induzir a uma mudança na escolha alimentar. / Background: Rheumatoid arthritis is a chronic inflammatory disease associated with changes in energy and protein metabolism. Objective: To investigate food preferences during the development of chronic inflammation in rats with collagen-induced arthritis (CIA). Methods: Female Wistar rats were separated into two groups, control (CO, n=10) and CIA (n=11), and were simultaneously exposed to four different diets (standard, hypercaloric, hyperlipidic and hyperproteic). During the experimental period was observed clinical evidence of disease, food intake, body weight and biochemical parameters, as well as skeletal muscle weight at the end of the experiment. Statistical tests were two-away ANOVA and t-test and significance level for these tests was 95%. Results: CIA animals demonstrate voluntary reduction in total food intake, reduced body weight and reduced relative muscle weight compared to CO animals. In addition, CIA animals increased relative comsuption of high protein diet, decreased serum concentrations creatinine, triglycerides and glucose. Conclusion: Chronic inflammatory conditions such as rheumatoid arthritis cause changes in protein and energy metabolism, and these physiological alterations may induce a change in food choice.

Introdução: Artrite reumatoide é uma doença inflamatória crônica associada a alterações no metabolismo proteico e energético. Objetivos: Investigar a preferência alimentar durante o desenvolvimento da inflamação crônica em ratas com artrite induzida por colágeno. Métodos: Ratas Wistar fêmeas foram alocadas em dois grupos: controle (CO, n=10) e artrite induzida por colágeno (CIA; n=11) e expostas simultaneamente a quatro diferentes dietas (padrão, hipercalórica, hiperlipidica e hiperproteica). Durante o período experimental foi observado dados clínicos da doença, consumo alimentar, peso corporal e parâmetros bioquímicos, bem como, peso muscular esquelético ao final do experimento. Os testes estatísticos realizados foram ANOVA de duas vias e test-t e nível de significância estabelecido para estes testes foi de 95%. Resultados: Os animais com artrite induzida demostram redução voluntária da ingestão total de alimento, redução do peso corporal e redução da relação sarcossomática quando comparados aos animais controles. Ainda, o grupo artrite aumentou o relativo consumo de dieta hiperproteíca, diminuiu as concentrações séricas de creatinina, triglicerídeos e glicose. Conclusão: Condições inflamatórias crônicas como a artrite reumatoide causam alterações no metabolismo energético e proteíco e estas alterações fisiológicas podem induzir a uma mudança na escolha alimentar. / Background: Rheumatoid arthritis is a chronic inflammatory disease associated with changes in energy and protein metabolism. Objective: To investigate food preferences during the development of chronic inflammation in rats with collagen-induced arthritis (CIA). Methods: Female Wistar rats were separated into two groups, control (CO, n=10) and CIA (n=11), and were simultaneously exposed to four different diets (standard, hypercaloric, hyperlipidic and hyperproteic). During the experimental period was observed clinical evidence of disease, food intake, body weight and biochemical parameters, as well as skeletal muscle weight at the end of the experiment. Statistical tests were two-away ANOVA and t-test and significance level for these tests was 95%. Results: CIA animals demonstrate voluntary reduction in total food intake, reduced body weight and reduced relative muscle weight compared to CO animals. In addition, CIA animals increased relative comsuption of high protein diet, decreased serum concentrations creatinine, triglycerides and glucose. Conclusion: Chronic inflammatory conditions such as rheumatoid arthritis cause changes in protein and energy metabolism, and these physiological alterations may induce a change in food choice.

The effect of the dietary macronutrient composition on weight loss has been a controversial issue for decades. During that time, a high-protein, high-fat, and low-carbohydrate diet has been one of the more popular weight loss diets with the public. We hypothesized that a computer simulation model using STELLA software could help to better understanding the effect of the dietary macronutrient composition on weight loss. We calculated daily total oxidation instead of total energy expenditure as others have done based on the facts that carbohydrate, fat, and protein intake influence carbohydrate, fat, and protein oxidation. In order to create a simple and accurate model comparing dietary macronutrient composition effects, we eliminated exercise as a factor and focused on a sedentary population. The model was validated by five sets of published human data. Following model validation, simulations were carried out to compare the traditional high-carbohydrate diet recommended by the American Dietetic Association and two well-known high-protein diets (Atkins and the Zone diet). The results of computer simulation suggested that the lean tissue retention effect of a high-protein diet, especially with a lower-fat diet, compared with a traditional high carbohydrate diet over 6 months.

No description available.

L'encéphalopathie hépatique (EH) est une complication grave de la cirrhose, provoquant des troubles de mémoire, de coordination motrice et de sommeil, avec une progression vers le coma et la mort. Le stress oxydatif dû au foie défaillant et l'ammoniac provenant de la dégradation des protéines alimentaires sont des facteurs pathogènes connus. Simultanément, l'hyperammoniémie et la malnutrition protéino-calorique contribuent à la sarcopénie. Comme les muscles sont le principal mécanisme d'élimination de l'ammoniac pendant la cirrhose, il existe un cercle vicieux où l'hyperammonémie contribue à l'EH et à la sarcopénie, et la sarcopénie contribue à l'hyperammonémie et à l'EH. Notre objectif était de déterminer les effets d’un régime riche en protéines de lactosérum ou de soja administré à long terme, sur la masse musculaire, l'hyperammonémie, et l'EH chez les rats cirrhotiques. Ensuite, nous voulions déterminer les effets d’un gavage aigu de protéines sur l'hyperammonémie et l'EH. Nos résultats montrent qu'un apport élevé en protéines à long terme n'a pas maintenu la masse musculaire ou diminué l'ammoniac, mais que le stress oxydatif a été réduit, ce qui a conduit à la prévention de l'EH, améliorant la mémoire à court et à long terme, l'anxiété, et l'activité locomotrice. Un gavage aigu de protéines chez les rats cirrhotiques n’a pas augmenté l'ammoniac ni précipité l'EH. Cette étude est la première à évaluer l'effet d'un régime élevé en protéines chez des rats cirrhotiques pour observer la masse musculaire, l'ammoniac et l'EH. Nos résultats soutiennent la sécurité et l'efficacité d'une stratégie nutritionnelle riche en protéines dans la cirrhose. / Hepatic encephalopathy (HE) is a serious complication of liver disease, causing impairments in memory, motor coordination, sleep, with progression to coma and death. It affects up to 70% of patients, severely impacting quality of life. Oxidative stress from the failing liver and ammonia from the breakdown of dietary protein are known pathogenic factors. Concurrently, hyperammonemia and protein-calorie malnutrition contribute to muscle wasting, sarcopenia. As muscle is the main clearance mechanism for ammonia during cirrhosis, a vicious cycle exists where elevated ammonia contributes to HE and sarcopenia, and sarcopenia in turn contributes further to hyperammonemia and HE. Our aim was to determine whether long-term high protein whey or soy diets administered from the onset of liver disease in rats could maintain muscle mass, decrease hyperammonemia, and prevent symptoms of HE. Secondly, we wanted to determine the effects an acute load of high protein on hyperammonemia and HE in cirrhotic rodents. Our results show that long-term high protein intake did not maintain muscle mass or decrease ammonia, but oxidative stress was reduced, leading to HE prevention, as shown by the improvement of short- and long-term memory, anxiety, and locomotor activity. An acute load of protein was shown to be safe in cirrhotic rodents, with no increase in ammonia or precipitation of HE. This study is the first of its kind to evaluate the effect of high protein intake in cirrhotic rodents to observe muscle mass, ammonia, and HE. Our results support the safety and efficacy of a high protein nutritional strategy in cirrhosis.

Dans l'alimentation des pays industrialisés, l'apport en protéines est bien supérieur à l'apport nutritionnel conseillé (ANC). De plus, cet apport peut être encore supérieur lors de la consommation de régimes riches en protéines utilisés à des fins de perte de poids par des personnes obèses ou en surpoids. Cependant, les conséquences des régimes riches en protéines au niveau de l'écosystème du gros intestin sont encore très mal connues. Dans la première partie de cette thèse, nous avons étudié l'impact d'un régime hyperprotéique sur le microbiote, le contenu endoluminal du gros intestin et le métabolisme des colonocytes. Les rats ont consommé pendant 15 jours soit un régime hyperprotéique (53% de protéines) soit un régime normoprotéique (14% de protéines). Nous avons observé que le régime hyperprotéique réduit la quantité des groupes bactériens majeurs comme Clostridium coccoides et Clostridium leptum, ainsi que Faecalibacterium prausnitzii dans le microbiote du gros intestin avec conjointement des modifications sur sa biodiversité. En même temps, les quantités des produits finaux de la fermentation des acides aminés par le microbiote, les acides gras à chaîne courte (AGCC) et les acides gras à chaîne branchée sont fortement augmentées. Cependant, l'expression des transporteurs des acides monocarboxyliques et l'oxydation du butyrate par les colonocytes ne sont pas modifiés en lien avec des modifications mineures des concentrations en AGCC dues à une augmentation des contenus du gros intestin après l'ingestion du régime hyperprotéique. Il en résulte une augmentation de l'excrétion des AGCC dans les fèces. Ces phénomènes permettraient une homéostasie du métabolisme du butyrate dans les colonocytes, en lien avec le rôle crucial de cet AGCC sur l'épithélium du côlon. Dans la deuxième partie de cette thèse, nous avons testé l'effet d'un mélange d'acides aminés (Thr, Met et Glu) sur la cicatrisation de la muqueuse colique après une colite induite par le DSS (dextran sodium sulfate) ; un modèle d'étude des maladies inflammatoires intestinales souvent utilisé. Une optimisation de la cicatrisation de la muqueuse intestinale émerge comme une cible thérapeutique, dans la prise en charge de ces maladies. La colite a été induite chez le rat avec 5% (w/v) de DSS pendant 6 jours, puis, à l'arrêt du traitement DSS, les animaux ont soit reçu le mélange d'acides aminé soit l'Ala comme témoin iso-azoté, pendant 3, 7 et 10 jours. Nous avons observé que 10 jours de complément en mélange d'acides aminés améliorent la cicatrisation post-colite, avec des modifications sur le taux de synthèse protéique dans la muqueuse colique, sans toutefois modifier la résolution de l'inflammation. Nos résultats suggèrent que l'utilisation des mélanges d'acides aminés améliore la cicatrisation de la muqueuse colique après colite chimio-induite. / In industrialized countries, protein intake is largely higher than the recommended dietary allowance (RDA). Furthermore, high protein diets are used for their slimming effect by obese or overweight people. However, little is known regarding to the consequences of a high protein diet on the large intestinal ecosystem. We thus study the influence of a high protein diet on the microbiota, on the endoluminal composition of the large intestine and on the butyrate metabolism by isolated colonocytes. Rats received during 15 days either a high protein diet (53% of proteins) or a normo protein diet (14% of proteins). We observed that the quantity of major bacterial groups Clostridium coccoides and Clostridium leptum, but also Faecalibacterium prausnitzii was reduced in the microbiota of the large intestine together with modifications of its biodiversity. In the same time, the quantities of short-chain fatty acids (SCFA) and branched-chain fatty acids, final products of bacterial fermentation of amino acids, were increased. However, the expression of monocarboxylic acid transporters and butyrate oxidation in colonocytes remained unchanged, in association with minor changes of the SCFA concentrations due to marked increase of the weight of the large intestine content. We then observed an increase in the amount of SCFA in the feces. These phenomena would allow homeostatic metabolism of butyrate in colonocytes, in relationship with its crucial role on the colonic epitheliumIn. In the second part of this thesis, we have tested the effects of a mixture of amino acids (Thr, Met and Glu) on the colonic mucosa healing after colitis induced by DSS (dextran sodium sulphate); a model to study intestinal inflammatory bowel diseases largely used. Optimization of intestinal mucosa healing is more and more considered as a therapeutic goal. Colitis was induced in rats by 5% (w/v) DSS during 6 days, then at the end of the treatment with DSS, animals received either the amino acid mixture or Ala as iso-nitrogenous control, during 3, 7 or 10 days. We observed that 10 days amino acid mixture supplementation was able to improve the colonic mucosal healing, with modification of the protein synthesis rate, without however changes in the resolution of inflammation. Our results suggest that the supplementation with the amino acid mixture improve the mucosal healing after experimental colitis.

Metabolic syndrome (MetS) and abdominal obesity (AbOb) increase the risk of developing cardiovascular disease and diabetes. Energy restriction (ER), highprotein (PRO) intake and high-intensity interval training (HIT) can independently improve MetS and AbOb. However, ER reduces metabolically active lean body mass (LBM) in addition to body fat (BF). Purpose: To determine the effects of a 16-wk ER diet with 2 levels of PRO (15% or 25% of energy), plus HIT, on MetS risk factors, AbOb, and body composition in women. Methods: Sedentary, premenopausal women (age=35±10y) with AbOb (waist circumference [WC] ≥80cm) were randomized to a 16-wk ER diet (-300kcals/d) with 15% (15PRO; n=17) or 25% (25PRO; n=18) of energy from PRO, plus 45min/d, 3d/wk HIT and 45min/d, 2d/wk continuous moderate-intensity exercise (CME) (-200kcals/d). Diet and physical activity (PA) were assessed using 4-d weighed food and PA records, respectively; diet and exercise compliance were assessed monthly with multiple-pass 24-h recalls and weekly tracking logs. Body weight (BW), WC, DXA-assessed body composition (BF [%], BF [kg], trunk fat [kg], and LBM [kg]), blood lipids (total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], triglycerides [TG]), glycemic markers (fasting plasma glucose [FPG], insulin, and homeostatic model assessment for insulin resistance [HOMA-IR], beta cell function [HOMA-%β] and insulin sensitivity [HOMA-%S]) and resting blood pressure (BP) (systolic BP [SBP]; diastolic BP [DBP]) were assessed pre/post-intervention. Repeated measures analysis of variance and two sample t-tests were used at analyze the date. Results are reported as means±standard deviations. Results: There were significant time, but not group, differences in BW (-5.1±2.6kg, p=0.0141), WC (- 7.3±3.6cm, p<0.0001), TC (-18.1±17.4mg/dL, p<0.0001), LDL-C (12.2± 16.2mg/dL, p<0.0001), TG (-25.3±56.2mg/dL, p=0.0064), insulin (-2.1±4.2mg/dL, p=0.0048), HOMA-IR (-0.2±0.5, p=0.0062), HOMA-%β (-12.1±35.2%, p=0.0497), HOMA-%S (28.5±78.4%, p=0.0357), and SBP (-3±9mmHg, p=0.214). There were significant group x time differences in DBP (15PRO=-5±8mmHg, 25PRO=- 2±8mmHg; p=0.0024). There were no time or group differences in FPG or HDLC. There were significant time, but not group, effects on changes in BW (-5.1kg± 2.6, p<0.0001), BF (-3.3±1.6%, p<0.0001), and LBM (-0.6kg±1.5, p=0.0283). The 15PRO group lost more absolute whole BF (-5.2kg vs. -3.9kg, p=0.0355) and trunk fat (-3.1kg vs. -2.2kg) vs. the 25PRO group. Conclusion: Both diets significantly improved BW, AbOb, MetS risk factors, glycemic control, and BF (%); LBM (kg) loss was similar in both groups. Compared to the 15PRO diet had significantly greater absolute BF-kg and trunk fat-kg losses. Increased PRO intake did not improve AbOb or MetS risk beyond ER and HIT/CME. The impact of HIT/CME and the greater (-1.3kg) changes in BW in the 15PRO group may have contributed significantly to the changes in absolute BF and trunk fat. More research is needed to separate the impact of HIT/CME and weight loss from the impact of PRO during ER. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 28, 2013 - March 28, 2014

Intermittent fasting (IF) is a recently popularized meal timing strategy whereby individuals abstain continuously from any energy intake for 16 to 20 hours each day, subsequently condensing energy intake into a short period spanning 4 to 8 hours. We aimed to test the effects of intermittent fasting in 10 individuals with Type 2 Diabetes Mellitus in conjunction with recommendations to consume a high protein diet in a 6 to 8 week withdrawal study. This study consisted of three phases: baseline, intervention, and follow-up. During the 2-week baseline and intervention phases participants consumed meals at regular times. Biochemical, anthropometric, and physical activity measurements were taken at the end of each phase. Participants reported morning, afternoon and evening self-monitored blood glucose and fasting duration on a daily basis, in addition to completing a remote food photography diary three times within each study phase. Despite the short duration of the intervention phase, intermittent fasting led to significant decreases in weight, BMI, morning SMBG, and overall reductions in waist circumference, C-reactive protein, energy intake, carbohydrate intake, and fat intake. There were significant variations between participants in response to intermittent fasting in respect to changes in lipids and insulin sensitivity, which could not be explained by baseline biochemical or anthropometric measures, fasting duration, energy intake, or physical activity. Upon cessation of intermittent fasting, biochemical changes regressed towards baseline values during the follow-up period. Intermittent fasting was well tolerated by most participants, and no severe adverse events were noted. Morning nausea was the most common complaint, which abruptly ceased when medication timing was changed.

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