Doctor of Philosophy / Department of Animal Sciences and Industry / Mike Tokach / In 11 experiments, 7,325 pigs were used to determine the effects of: 1) diet type and form on finishing pig growth performance and carcass fat iodine value (IV); 2) pellet quality and feeder adjustment on pig growth performance; 3) corn particle size and diet form on finishing pig growth performance and carcass characteristics; and 4) dietary acidification, diet complexity, and feed-grade antibiotics on nursery pig growth performance. Feeding diets with wheat middlings and dried distillers grains with solubles all the way until marketing decreased G:F and carcass yield, and worsened carcass fat IV. Withdrawing these ingredients 17 d prior to market restored carcass yield, but resulted in small improvements in IV. Pelleting diets improved growth performance; however, a novel finding is that pelleting diets fed to finishing pigs increased belly fat IV. Feeding nursery pigs from a wide feeder gap may improve ADG and ADFI, with no negative effects on G:F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G:F. In all experiments, feeding pelleted diets improved G:F, but the greatest improvements occurred when the percentage of fines was minimized. Grinding corn finer than 650 microns decreased ADFI and improved G:F for finishing pigs fed meal diets, but not for pigs fed pelleted diets. Pelleting diets improved ADG and G:F, but the greatest magnitude of G:F improvement to pellets occurred when pigs were fed diets containing the largest particle size corn. Thus, grinding corn finer than 650 microns improved feed efficiency for finishing pigs fed meal diets, but provided no additional benefit for pigs fed pelleted diets. When dietary supplementation of benzoic acid was evaluated, added benzoic acid in nursery pig diets did not influence growth performance in university conditions, whereas feeding complex diets or antimicrobials improved growth. In the commercial setting, acidifiers improved growth in one experiment but not the other. The varying response to acidifiers is likely influenced by health status, age, or starting weight of pigs.

O objetivo desse estudo foi investigar a associação da inflamação com a resistência periférica à insulina (RI) na vigência de dietas obesogênicas, suplementação com óleo de peixe (SOP) e ausência de TLR-4. Os animais receberam dieta balanceada (DB), DB e leite condensado (DB+LC), hiperlipídica (HFD) ou HFD+LC. DB+LC e HFD levaram ao aumento: no ganho de massa corpórea (MC) e expressão de F4/80 e leptina no tecido adiposo (TA) em relação à DB. Em relação à HFD, HFD+LC provocou: aumento no HOMA-IR (4x), nos conteúdos de IL-6, IL-10, TNF-a, IL-1b, ICAM-1, VCAM-1 e leptina no TA. Comparada à DB+LC, HF+LC aumentou: a MC, HOMA-IR e expressão de F4/80 e reduziu a expressão de leptina no TA. A SOP nos animais em DB reduziu a expressão de F4/80, TNF-a e TLR-4 no fígado. A SOP em HFD reduziu o MC, HOMA-IR e aumentou o conteúdo de adiponectina no TA. A deleção de TLR-4 elevou o MC em DB+OP e a gordura mesentérica no HFD+OP. Assim, o consumo elevado de gordura ou açúcar causou obesidade e a associação de ambos potencializou a obesidade e induziu RI e inflamação no TA. A suplementação com OP atenuou a inflamação associada à DB e a obesidade e RI na vigência de HFD, sendo esses efeitos dependentes de TLR-4. / The aim of this study was to investigate the association between inflammation and insulin resistance (IR) under obesogenic diets, fish oil supplementation (FOS) and TLR-4-/-. The mice were fed a balanced diet (BD), BD and condensed milk (BD+CM), high-fat diet (HFD) or high-fat diet and condensed milk (HFD+CM). The BD+CM and HFD increased: body weight gain (BWG), F4/80 and leptin in adipose tissue (AT). The HFD+CM compared to HFD increased: HOMA-IR, the contents of IL-6, IL-10, TNF-a, IL-1b, ICAM-1, VCAM-1 and leptin in AT. As compared to BD+CM, HFD+CM increased: BWG, HOMA-IR, F4/80 and reduced the leptin in AT. The FOS+BD reduced F4/80, TNF-a and TLR-4 in the liver. The FOS+HFD reduced BWG, HOMA-IR and increased the adiponectin in AT. TLR-4 deletion increased BWG in the FOS+BD and mesenteric fat in the FOS+HFD groups. The high consumption of fat or sugar induced obesity and the association of both potentiated this effect leading to IR and inflammation in adipose tissue and perivascular fat. FO supplementation attenuated the inflammation when associated with BD and the obesity and IR induced by HFD in a TLR-4 dependent-manner.

Chronic low-grade inflammation is associated the Metabolic Syndrome (MetS) and may contribute to its development. A diet high in saturated fat (SFA) has been associated with increased inflammation and development of the MetS. SFAs have been shown to elicit pro-inflammatory signaling through proteins of innate immunity, TLR4 and Nods 1 and 2. We determined whether common polymorphisms in the genes of these proteins could modify the association between fat intake and biomarkers of the MetS. Fat intake was measured using a food frequency questionnaire and genotyping was completed using real-time PCR. The TLR4 Asp299Gly (rs4986790) polymorphism was associated with decreased insulin sensitivity while an intronic polymorphism (rs5030728) modified the association between dietary SFA and HDL-cholesterol. The Nod1 Glu266Lys polymorphism modified the association between dietary SFA and HOMA-IR. These results suggest a role for innate immunity in mediating some of the effects of dietary SFAs on factors associated with the MetS.

Chronic low-grade inflammation is associated the Metabolic Syndrome (MetS) and may contribute to its development. A diet high in saturated fat (SFA) has been associated with increased inflammation and development of the MetS. SFAs have been shown to elicit pro-inflammatory signaling through proteins of innate immunity, TLR4 and Nods 1 and 2. We determined whether common polymorphisms in the genes of these proteins could modify the association between fat intake and biomarkers of the MetS. Fat intake was measured using a food frequency questionnaire and genotyping was completed using real-time PCR. The TLR4 Asp299Gly (rs4986790) polymorphism was associated with decreased insulin sensitivity while an intronic polymorphism (rs5030728) modified the association between dietary SFA and HDL-cholesterol. The Nod1 Glu266Lys polymorphism modified the association between dietary SFA and HOMA-IR. These results suggest a role for innate immunity in mediating some of the effects of dietary SFAs on factors associated with the MetS.

abstract: The Western Pattern diet has been characterized by having greater than 50 percent consumption coming from fat and sugar. This macronutrient allocation has been shown to have deleterious effects on endothelial function and metabolic markers of cardiovascular disease. Exercise has been shown to improve vascular reactivity and metabolic markers related to cardiovascular health. The objective of the study was to determine if exercise training can prevent the anticipated deleterious effects of a fat-sugar supplemented diet on endothelial function and blood markers of cardiovascular risk in young men. Twenty-one, healthy college-aged males were randomly assigned to either the doughnut + exercise or doughnut only groups. Both groups were fed 2 doughnuts per day, 6 days per week, for three weeks, while maintain their current diet. The exercise group completed 4 exercise training sessions per week consisting of 2 high intensity interval training bouts (up to 95% VO2peak) on a cycle ergometer and two moderate intensity, steady-state bouts (at 75% VO2peak) on a treadmill. Changes in body weight and composition, markers of endothelial function, oxidative stress, serum lipids, and blood glucose were measured in each group. As expected, cardiovascular fitness increased significantly in the doughnut-supplemented + exercise group as compared to the doughnut-supplemented (p=0.005). Significant increases in body weight (p=0.036), fat mass (p=0.013), and body fat percentage (p=0.014) were seen in the doughnut only group as compared to the doughnut + exercise group. The doughnut + exercise group showed significant improvements in fasting serum triglycerides (p=0.036), plasma insulin (p=0.039) and insulin sensitivity (HOMA; p=0.05) as compared to the doughnut only group. The doughnut + exercise group saw a significant improvement in nitric oxide availability whereas the doughnut only group experienced a significant decline (p=0.014). There were no significant changes in other markers. Despite the addition of a fat/sugar supplement of ~11,600 kcal over three weeks, 4 exercise sessions per week were sufficient to prevent a gain in body weight and fat mass, and also improve some measures of cardiometabolic risk. These results suggest that exercise may be necessary to prevent some adverse health outcomes associated with transient periods of excessive energy consumption. / Dissertation/Thesis / Ph.D. Physical Activity, Nutrition and Wellness 2013

O objetivo desse estudo foi investigar a associação da inflamação com a resistência periférica à insulina (RI) na vigência de dietas obesogênicas, suplementação com óleo de peixe (SOP) e ausência de TLR-4. Os animais receberam dieta balanceada (DB), DB e leite condensado (DB+LC), hiperlipídica (HFD) ou HFD+LC. DB+LC e HFD levaram ao aumento: no ganho de massa corpórea (MC) e expressão de F4/80 e leptina no tecido adiposo (TA) em relação à DB. Em relação à HFD, HFD+LC provocou: aumento no HOMA-IR (4x), nos conteúdos de IL-6, IL-10, TNF-a, IL-1b, ICAM-1, VCAM-1 e leptina no TA. Comparada à DB+LC, HF+LC aumentou: a MC, HOMA-IR e expressão de F4/80 e reduziu a expressão de leptina no TA. A SOP nos animais em DB reduziu a expressão de F4/80, TNF-a e TLR-4 no fígado. A SOP em HFD reduziu o MC, HOMA-IR e aumentou o conteúdo de adiponectina no TA. A deleção de TLR-4 elevou o MC em DB+OP e a gordura mesentérica no HFD+OP. Assim, o consumo elevado de gordura ou açúcar causou obesidade e a associação de ambos potencializou a obesidade e induziu RI e inflamação no TA. A suplementação com OP atenuou a inflamação associada à DB e a obesidade e RI na vigência de HFD, sendo esses efeitos dependentes de TLR-4. / The aim of this study was to investigate the association between inflammation and insulin resistance (IR) under obesogenic diets, fish oil supplementation (FOS) and TLR-4-/-. The mice were fed a balanced diet (BD), BD and condensed milk (BD+CM), high-fat diet (HFD) or high-fat diet and condensed milk (HFD+CM). The BD+CM and HFD increased: body weight gain (BWG), F4/80 and leptin in adipose tissue (AT). The HFD+CM compared to HFD increased: HOMA-IR, the contents of IL-6, IL-10, TNF-a, IL-1b, ICAM-1, VCAM-1 and leptin in AT. As compared to BD+CM, HFD+CM increased: BWG, HOMA-IR, F4/80 and reduced the leptin in AT. The FOS+BD reduced F4/80, TNF-a and TLR-4 in the liver. The FOS+HFD reduced BWG, HOMA-IR and increased the adiponectin in AT. TLR-4 deletion increased BWG in the FOS+BD and mesenteric fat in the FOS+HFD groups. The high consumption of fat or sugar induced obesity and the association of both potentiated this effect leading to IR and inflammation in adipose tissue and perivascular fat. FO supplementation attenuated the inflammation when associated with BD and the obesity and IR induced by HFD in a TLR-4 dependent-manner.

Background Risk factors for chronic non-communicable diseases have been shown to track from childhood into adulthood. Cost-effective intervention starts with valid screening. The aim of this research was development and comparative validation of a dietary fat screener in grade six learners. Methods A pictorial, quantitative food frequency questionnaire type, scored dietary fat screener (test method), consisting of ten food categories associated with high fat intakes, was developed and subjected to developmental evaluations in the target group. Subsequently the test method was administered to learners of an urban middle-class school (Pretoria, South Africa). Test-retest reproducibility was checked in a random sub-sample. Two reference methods were used for comparison: Parental completion of the screener and a three-day food record by the children. Reliability testing of the test method involved measuring internal consistency and test-retest reproducibility. Credibility of energy intakes in the food record was checked. Mean cholesterol intake and percentage fat and saturated fat energy were determined. Comparative validation was based on correlations, mean differences and the Bland Altman method for continuous variables. Percentage agreement, kappa statistics and the McNemar tests were determined for categorical data, as were sensitivity, specificity and predictive values. Receiver operating characteristic curves were plotted. Results Sample: Out of 108 children, 39 (100%) were re-tested, 93 (86%) provided usable food records and 78 (72%) parents responded. Mean age was 148±4.4 months. Reliability: The test method was internally consistent. Test-retest reproducibility of portion size and frequency of intake estimates depended on the food category. No systematic error between administrations was noted as mean category and final score differences between the two administrations did not differ significantly from zero. A significant (r=0.36, P=0.02) correlation existed between administrations, but boys were characterised by random error and a lack of reproducibility (r=0.26, P=0.29), whilst for girls reproducibility could be established (r=0.58, P=0.01). Comparison to screener by parents: Children and parents did not agree in respect of reported portion size and frequency of intake. Parents had lower values for all scores. Correlation between children’s and parents’ final scores was 0.23 (P=0.04) (boys: r=0.13, P=0.46; girls: r=0.33, P=0.04), but the mean difference in final scores differed significantly from zero (P=0.0001). Classification was identical in 74% of cases, but when corrected for chance this agreement was also poor. Comparison to food record: The food record appeared to be a plausible reflection of energy intakes during the recording period. For girls a significant (P<0.05) correlation between test method final score versus cholesterol intake and energy from total and saturated fat was found. The sensitivity of the test method was very high (over 90%). Chance corrected agreement between test method classification and measures of fat intake from the food record was poor. Changing the cut-off of the test method final score could not achieve high sensitivity and high specificity simultaneously. Conclusion The dietary fat screener cannot yet be used as sole indicator of high fat intake in grade six learners. Until the discriminatory abilities have been improved, its value lies in creating awareness of high fat intakes and providing a food-based starting point for anticipatory guidance. / Thesis (PhD (Human Nutrition))--University of Pretoria, 2006. / Human Nutrition / unrestricted

No description available.

Os ácidos graxos e índices de qualidade da gordura da dieta tem papel importante na homeostase glicêmica, mas estudos sobre o consumo alimentar desses nutrientes e sua associação com o diabetes mellitus gestacional (DMG) são escassos. O objetivo do presente estudo consistiu na investigação da relação entre o diabetes gestacional e a ingestão usual de ácidos graxos específicos e de índices de qualidade da gordura da dieta de mulheres no segundo trimestre gestacional. Estudo transversal conduzido entre 799 gestantes adultas de Ribeirão Preto-SP-Brasil. Para a estimativa da dieta usual o Multiple Source Method foi utilizado, empregando-se dois IR24h obtidos a partir da 24a semana gestacional. As gestantes foram entrevistadas enquanto realizavam teste oral de tolerância à glicose e os critérios da International Association of Diabetes and Pregnancy Study Groups foram empregados para o diagnóstico do DMG. A associação entre os tercis de ácidos graxos da dieta durante a gestação e o DMG foi avaliada por análises de regressão logística, ajustadas por idade, escolaridade, paridade, semana gestacional, IMC pré-gestacional e atual, DMG prévia, histórico familiar de diabetes, tabagismo, prática de atividade física, fibra dietética, energia e ácidos graxos. A média (DP) de idade das gestantes avaliadas foi de 28 (5) anos e 18,9% apresentaram DMG. Verificou-se associação inversa entre o maior tercil de ingestão de ácidos graxos ômega 3 totais [0,21(0,08-0,56)] e ácido graxo linolênico [0,28(0,11-0,71)] e o DMG, após ajuste múltiplo. Observou-se associação direta entre o terceiro tercil do índice de trombogenicidade da dieta [2,55(1,30-5,02)] e associação inversa entre o maior tercil da razão HH [0,43(0,23-0,80)] e o DMG, quando comparados ao menor tercil, após ajuste múltiplo. A qualidade da gordura da dieta durante a gestação é fortemente associada com o diabetes mellitus gestacional. / Fatty acids and indices of dietary fat quality plays an important role in glucose homeostasis, but studies on the dietary intake of these nutrients and its association with gestational diabetes mellitus (GDM) are scarce. The aim of the present study was to investigate the relationship between GDM and the usual intake of specific fatty acids and indices of dietary fat quality in women in the second trimester of pregnancy. This was a cross-sectional study conducted with 799 adult pregnant women in Ribeirão Preto (Sao Paulo), Brazil. We used the Multiple Source Method to estimate participants usual diet, employing two IR24hs obtained from the 24th week of gestation. The women were interviewed when they came in for their oral glucose tolerance test and GDM was diagnosed using the International Association of Diabetes and Pregnancy Study Groups criteria. We used logistic regression analysis to assess the correlation between GDM and dietary fatty acid tertiles during pregnancy, adjusted for age, education, parity, gestational week, pre-pregnancy and current BMI, prior GDM, family history of diabetes, smoking, physical activity, dietary fiber, energy and fatty acids. The mean (SD) age of the pregnant women was 28 (5) years and 18.9% had GDM. There was an inverse correlation between the highest tertile of total omega 3 intake [0.21 (0.08-0.56)] and linolenic fatty acid intake [0.28 (0.11-0.71)] and GDM, after multiple adjustments. We observed a positive correlation between GDM and the highest tertile of the dietary index of thrombogenicity [2.55 (1.30-5.02)] and a negative correlation between GDM and the highest tertile of the hypocholesterolaemic/hypercholesterolaemic fatty acids ratio [0.43 (0.23-0.80)], after multiple adjustments. The quality of dietary fat during pregnancy is strongly associated with gestational diabetes mellitus.

Os ácidos graxos e índices de qualidade da gordura da dieta tem papel importante na homeostase glicêmica, mas estudos sobre o consumo alimentar desses nutrientes e sua associação com o diabetes mellitus gestacional (DMG) são escassos. O objetivo do presente estudo consistiu na investigação da relação entre o diabetes gestacional e a ingestão usual de ácidos graxos específicos e de índices de qualidade da gordura da dieta de mulheres no segundo trimestre gestacional. Estudo transversal conduzido entre 799 gestantes adultas de Ribeirão Preto-SP-Brasil. Para a estimativa da dieta usual o Multiple Source Method foi utilizado, empregando-se dois IR24h obtidos a partir da 24a semana gestacional. As gestantes foram entrevistadas enquanto realizavam teste oral de tolerância à glicose e os critérios da International Association of Diabetes and Pregnancy Study Groups foram empregados para o diagnóstico do DMG. A associação entre os tercis de ácidos graxos da dieta durante a gestação e o DMG foi avaliada por análises de regressão logística, ajustadas por idade, escolaridade, paridade, semana gestacional, IMC pré-gestacional e atual, DMG prévia, histórico familiar de diabetes, tabagismo, prática de atividade física, fibra dietética, energia e ácidos graxos. A média (DP) de idade das gestantes avaliadas foi de 28 (5) anos e 18,9% apresentaram DMG. Verificou-se associação inversa entre o maior tercil de ingestão de ácidos graxos ômega 3 totais [0,21(0,08-0,56)] e ácido graxo linolênico [0,28(0,11-0,71)] e o DMG, após ajuste múltiplo. Observou-se associação direta entre o terceiro tercil do índice de trombogenicidade da dieta [2,55(1,30-5,02)] e associação inversa entre o maior tercil da razão HH [0,43(0,23-0,80)] e o DMG, quando comparados ao menor tercil, após ajuste múltiplo. A qualidade da gordura da dieta durante a gestação é fortemente associada com o diabetes mellitus gestacional. / Fatty acids and indices of dietary fat quality plays an important role in glucose homeostasis, but studies on the dietary intake of these nutrients and its association with gestational diabetes mellitus (GDM) are scarce. The aim of the present study was to investigate the relationship between GDM and the usual intake of specific fatty acids and indices of dietary fat quality in women in the second trimester of pregnancy. This was a cross-sectional study conducted with 799 adult pregnant women in Ribeirão Preto (Sao Paulo), Brazil. We used the Multiple Source Method to estimate participants usual diet, employing two IR24hs obtained from the 24th week of gestation. The women were interviewed when they came in for their oral glucose tolerance test and GDM was diagnosed using the International Association of Diabetes and Pregnancy Study Groups criteria. We used logistic regression analysis to assess the correlation between GDM and dietary fatty acid tertiles during pregnancy, adjusted for age, education, parity, gestational week, pre-pregnancy and current BMI, prior GDM, family history of diabetes, smoking, physical activity, dietary fiber, energy and fatty acids. The mean (SD) age of the pregnant women was 28 (5) years and 18.9% had GDM. There was an inverse correlation between the highest tertile of total omega 3 intake [0.21 (0.08-0.56)] and linolenic fatty acid intake [0.28 (0.11-0.71)] and GDM, after multiple adjustments. We observed a positive correlation between GDM and the highest tertile of the dietary index of thrombogenicity [2.55 (1.30-5.02)] and a negative correlation between GDM and the highest tertile of the hypocholesterolaemic/hypercholesterolaemic fatty acids ratio [0.43 (0.23-0.80)], after multiple adjustments. The quality of dietary fat during pregnancy is strongly associated with gestational diabetes mellitus.