The commercial hydrogenation of oils and fats results in the formation of, among other components, geometrical and positional isomers of monounsaturated fatty acids. The view that there may be hazards associated with such oils have occasionally been expressed. Prior to an investigation of the levels of such acids in human tissue and UK dietary fats, the synthesis of a series of these acids, as standards, and their characterisation, was necessary. For the synthetic programme, the general scheme provided a convenient route for the synthesis of geometrical and positional isomers from common precursors. When condensation of the 1-alkyne and a-chloro-w-iodoalkane was performed via sodamide in liquid ammonia, the scheme was limited but was extended somewhat when performed via methyllithium in dioxan. Generally, yields decreased with the increasing chain length, and migration of the unsaturated bond to the extremities of the resulting molecule. Chromatographic separation, both capillary column GLC and reversephase HPLC, was readily achieved on the basis of chain length and configuration of the double bond. Furthermore, the partial separation of positional isomers was achieved. NMR spectroscopy unambiguously determined the configuration and position of unsaturation in virtually every fatty acid. Assignment is based on the fact that functional groups within an acid alter the chemical shift of neighbouring carbons in a characteristic manner. No one of these techniques alone is applicable to the determination of positional isomerism in a complex lipid mixture and must be used in combination. Whereas NMR is undoubtedly invaluable in the quantification of positional isomers on an individual basis, or in profiling simple mixtures, it is not as applicable to the direct analysis of complex lipid samples. Emphasis on the continuing development of capillary column GLC holds the most promise for the direct quantification of positional isomerism.

Motivation The objective of the South African Avocado Growers Association (SAAGA) is to increase the demand of avocados by advertising, promoting and other means deemed fit by them. In order to promote and advertise a product, consumer research has to be done to determine the consumers' attitudes towards and beliefs concerning the product. These findings then need to be followed up by scientific studies, targeted at specific problems and target groups to yield scientific evidence. Little consumer research has been done on avocados and studies investigating the health effects of avocados are limited, with available literature only focussing on the cholesterol lowering effect of avocados. Objectives Firstly, the objective is to investigate the beliefs and attitudes of the South African consumer towards avocados and health; to determine whether gender, age group, race or living standard influence the consumers beliefs towards avocados. Secondly, the objective is to dispel the myth that avocados are fattening and should therefore be avoided in energy restricted diets; to examine the effects of avocados, a rich source of monounsaturated fatty acids, as part of an energy restricted diet on weight loss, serum lipids, fibrinogen and vascular function in overweight and obese subjects. Methods Consumer study: One thousand nine hundred and ninety-seven South African individuals, randomly selected from metropolitan areas in South Africa, participated in this survey. Data were weighed to reflect the adult metropolitan population based on gender, age and race distribution. The total population (10 695 000) was representative of both genders (5 423 000 men and 5 272 000 women) and major race groups (2 615 000 whites, 6 252 000 blacks, 1 255 000 coloureds and 573 000 Indians) from different age groups and living standards. The questionnaires were designed by a multidisciplinary team and consisted of seventeen foodrelated questionnaires, of which one questioned the beliefs regarding avocados. Trained field workers administrated questionnaires by conducting face-to-face interviews with consumers. The market research company, MARKINOR, was contracted to collect the data. Quantitative data was statistically analysed in order to generate the relevant descriptive statistics, cross tabulations and statistical tests. SUMMARY Dietary intervention study: Sixty one free-living volunteers (13 men; 48 women), with a mean (standard deviation) body mass index (BMI) of 32 (3.9) kg/m2, participated in this randomised, controlled parallel study. The subjects were paired according to gender, BMI and age and randomly assigned to one of two groups. The experimental group consumed 200 g of avocado (1 avocado) per day, substituting 30 g of other mixed dietary fats, and the control group excluded avocado from their energy restricted diet for six weeks. Seven-day isoenergetic menu plans were given according to mean energy requirements of both genders to provide 30% fat, 55% carbohydrates and 15% protein of total energy intake. Anthropometric measurements, physical activity, dietary intakes, blood pressure and arterial compliance were measured with standard methods at the beginning and end of the intervention. Fasting blood samples were drawn at the beginning and end of the intervention period. Results Consumer study: There were no practical significant differences in the consumers responses in terms of gender or age. Practical significant differences were found between different race and LSM (Living Standard Measure) groups for some variables. The overall response of consumers towards the effect of avocados on health, heart health, children's health and the health effects associated with the fat content of avocados were very positive. However, almost half the consumers are still not convinced of or are uncertain as to the cholesterol content of avocados, while 47% of the consumers still believe that avocados are fattening. More than 80% of the consumers agreed that avocados are a good source of vitamins and minerals, and 76% consider avocados to be a good source of fibre. Almost 70% of the consumers agreed that avocados are good for sportsmen and -women. Avocados were seen by 49% of the consumers to be an aphrodisiac. Dietary intervention study: Fifty-five subjects completed the study. Compliance with avocado intake in the experimental group was 94.6%. Anthropometric measurements (weight, body mass index and percentage body fat) decreased significantly in both groups during the study (p<0.001), and the change was similar in both groups. Serum lipid levels (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides), fibrinogen, blood pressure and arterial compliance did not change significantly within or between the two groups. SUMMARY Conclusions Consumer study: There are still a few myths and misconceptions that exist among some consumers regarding avocados, especially with regard to sexual functioning, cholesterol content, and fattening effect of avocados. The agricultural industry can use these results to plan different marketing campaigns focused on certain target groups to change the misperceptions concerning avocados and convey the positive nutritional value of avocados. Dietary intervention study: The consumption of 200 g avocado per day, within an energy restricted diet, does not compromise weight loss when substituted for 30 g of mixed dietary fat. The serum lipid levels, plasma fibrinogen, arterial compliance, as well as systolic and diastolic blood pressure were not affected by weight loss or avocado intake. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2004.

Motivation The objective of the South African Avocado Growers Association (SAAGA) is to increase the demand of avocados by advertising, promoting and other means deemed fit by them. In order to promote and advertise a product, consumer research has to be done to determine the consumers' attitudes towards and beliefs concerning the product. These findings then need to be followed up by scientific studies, targeted at specific problems and target groups to yield scientific evidence. Little consumer research has been done on avocados and studies investigating the health effects of avocados are limited, with available literature only focussing on the cholesterol lowering effect of avocados. Objectives Firstly, the objective is to investigate the beliefs and attitudes of the South African consumer towards avocados and health; to determine whether gender, age group, race or living standard influence the consumers beliefs towards avocados. Secondly, the objective is to dispel the myth that avocados are fattening and should therefore be avoided in energy restricted diets; to examine the effects of avocados, a rich source of monounsaturated fatty acids, as part of an energy restricted diet on weight loss, serum lipids, fibrinogen and vascular function in overweight and obese subjects. Methods Consumer study: One thousand nine hundred and ninety-seven South African individuals, randomly selected from metropolitan areas in South Africa, participated in this survey. Data were weighed to reflect the adult metropolitan population based on gender, age and race distribution. The total population (10 695 000) was representative of both genders (5 423 000 men and 5 272 000 women) and major race groups (2 615 000 whites, 6 252 000 blacks, 1 255 000 coloureds and 573 000 Indians) from different age groups and living standards. The questionnaires were designed by a multidisciplinary team and consisted of seventeen foodrelated questionnaires, of which one questioned the beliefs regarding avocados. Trained field workers administrated questionnaires by conducting face-to-face interviews with consumers. The market research company, MARKINOR, was contracted to collect the data. Quantitative data was statistically analysed in order to generate the relevant descriptive statistics, cross tabulations and statistical tests. SUMMARY Dietary intervention study: Sixty one free-living volunteers (13 men; 48 women), with a mean (standard deviation) body mass index (BMI) of 32 (3.9) kg/m2, participated in this randomised, controlled parallel study. The subjects were paired according to gender, BMI and age and randomly assigned to one of two groups. The experimental group consumed 200 g of avocado (1 avocado) per day, substituting 30 g of other mixed dietary fats, and the control group excluded avocado from their energy restricted diet for six weeks. Seven-day isoenergetic menu plans were given according to mean energy requirements of both genders to provide 30% fat, 55% carbohydrates and 15% protein of total energy intake. Anthropometric measurements, physical activity, dietary intakes, blood pressure and arterial compliance were measured with standard methods at the beginning and end of the intervention. Fasting blood samples were drawn at the beginning and end of the intervention period. Results Consumer study: There were no practical significant differences in the consumers responses in terms of gender or age. Practical significant differences were found between different race and LSM (Living Standard Measure) groups for some variables. The overall response of consumers towards the effect of avocados on health, heart health, children's health and the health effects associated with the fat content of avocados were very positive. However, almost half the consumers are still not convinced of or are uncertain as to the cholesterol content of avocados, while 47% of the consumers still believe that avocados are fattening. More than 80% of the consumers agreed that avocados are a good source of vitamins and minerals, and 76% consider avocados to be a good source of fibre. Almost 70% of the consumers agreed that avocados are good for sportsmen and -women. Avocados were seen by 49% of the consumers to be an aphrodisiac. Dietary intervention study: Fifty-five subjects completed the study. Compliance with avocado intake in the experimental group was 94.6%. Anthropometric measurements (weight, body mass index and percentage body fat) decreased significantly in both groups during the study (p<0.001), and the change was similar in both groups. Serum lipid levels (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglycerides), fibrinogen, blood pressure and arterial compliance did not change significantly within or between the two groups. SUMMARY Conclusions Consumer study: There are still a few myths and misconceptions that exist among some consumers regarding avocados, especially with regard to sexual functioning, cholesterol content, and fattening effect of avocados. The agricultural industry can use these results to plan different marketing campaigns focused on certain target groups to change the misperceptions concerning avocados and convey the positive nutritional value of avocados. Dietary intervention study: The consumption of 200 g avocado per day, within an energy restricted diet, does not compromise weight loss when substituted for 30 g of mixed dietary fat. The serum lipid levels, plasma fibrinogen, arterial compliance, as well as systolic and diastolic blood pressure were not affected by weight loss or avocado intake. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2004.

Growing evidence suggests that obesity and associated metabolic dysregulation occurs in concert with chronic low-grade inflammation. Toll-like receptors (TLR) are transmembrane receptors that play an important role in innate immunity and the induction of inflammatory responses. Our laboratory has observed that TLR4 expression is elevated in the skeletal muscle of obese humans and is associated with reduced fatty acid (FA) oxidation and increased lipid synthesis. Additionally, activation of this pathway by lipopolysaccharide (LPS), ex vivo, results in a shift in substrate metabolism favoring glucose as an energy substrate and preferential storage of FA in intracellular lipid depots. The purpose of this study was to examine the effects of saturated vs. monounsaturated FA on TLR4 transcription and signaling using ex vivo and in vivo models. C2C12 myotubes were incubated in FA-enriched growth medium with varying ratios of palmitate and oleate for 12 hours. Following FA treatment, cells were either collected for measures of mRNA and protein levels of TLR4 or challenged with LPS (500 ng/mL) for 2 hours to assess TLR4 mediated changes in interleukin-6 (IL-6) and glucose and fatty acid metabolism. TLR4 mRNA and protein content were increased in stepwise fashion with higher palmitate concentration (p<0.05). This was associated with an exacerbated LPS effect on IL-6 mRNA and protein levels, and glucose and fatty acid metabolism. To determine if these effects are translated to an in-vivo model, C57BL/6 mice were fed high saturated fat (HSF), high monounsaturated fat (HMF), and control diets for 10 weeks. Following the dietary intervention, animals were challenged with I.P. injections of either saline or LPS (~25μg/mouse), sacrificed 4 hours post-injection, and red and white gastrocnemius muscle were harvested for measures of expression and protein levels of TLR4 and IL-6, and glucose and fatty acid metabolism. TLR4 mRNA and protein levels were not altered with either the HSF or HMF diets. However, there was a heightened LPS response with regards to increases in IL-6 and TNF-α, and enhanced shifts in substrate metabolism following the HSF diet (p<0.05). These effects were not observed in response to the HMF diet. In conclusion, these data demonstrate that a milieu of high saturated fatty acids results in elevated sensitization of the TLR4 pathway in skeletal muscle. These results provide insight into how a westernized diet, one enriched in saturated fat, may link chronic inflammation with obesity-associated metabolic abnormalities. / Ph. D.

Introdução: Doenças cardiometabólicas são problemas de saúde pública mundial com repercussões sociais e econômicas. Dieta inadequada é apontada como um dos principais fatores de risco modificáveis, de importância central na prevenção destas doenças. Apesar da constatação de que certos nutrientes se associam a doenças, ainda existem dúvidas quanto às relações causais. Objetivos: 1) Revisar a participação dos alimentos e nutrientes na gênese e controle de doenças crônicas não-transmissíveis integrantes da síndrome metabólica (manuscrito 1); 2) Descrever de forma detalhada a estrutura do programa de intervenção interdisciplinar em hábitos de vida, desenvolvido para usuários da rede pública de saúde do município de São Paulo (manuscrito 2); 3) Investigar o efeito de mudanças em fatores dietéticos sobre o metabolismo glicídico, decorrentes de intervenção em hábitos de vida em indivíduos de risco cardiometabólico da rede pública de saúde (manuscrito 3). Métodos: Foram incluídos adultos com diagnóstico de pré-diabetes ou síndrome metabólica sem diabetes em ensaio clínico aleatorizado envolvendo dois tipos de intervenções de 18 meses: tradicional e intensiva. A intervenção tradicional consistiu de consultas trimestrais com endocrinologista; na intensiva, além dos atendimentos médicos, os indivíduos participaram de sessões psicoeducativas em grupo com equipe multiprofissional. As orientações dietéticas visaram à adequação do consumo de gorduras totais (redução de saturadas e trans e elevação de insaturadas) e aumento na ingestão de fibras. As variáveis coletadas nos momentos pré- e pós-intervenção incluíram dados sócio-demográficos, antropométricos, dietéticos e bioquímicos (glicemia de jejum e póssobrecarga, perfil lipídico, insulina, adiponectina, proteína C reativa, IL-6, TNF-, apolipoproteína A1 e B). A dieta foi avaliada por recordatórios de 24 horas, processados pelo Nutrition Data System software. Foram empregados os testes: t de Student, coeficientes de correlações, ANOVA com p de tendência e análises de regressão múltipla para identificar fatores dietéticos associados à melhora do metabolismo glicídico. Resultados: O manuscrito 1 consiste de um capítulo de livro (Nutrição em Saúde Coletiva) abordando aspectos epidemiológicos de doenças do espectro da síndrome metabólica com ênfase em fatores alimentares e estado nutricional. O manuscrito 2 detalha a estrutura, a equipe integrante, as orientações preconizadas e as principais estratégias psicoeducativas utilizadas no programa de intervenção em hábitos de vida desenvolvido (artigo metodológico submetido e website). Análises do manuscrito 3 mostraram que, ao final da intervenção, o aumento na ingestão de ácidos graxos monoinsaturados e fibras solúveis associaramse de forma independente à redução da glicemia de jejum e os primeiros também à melhora da glicemia pós-sobrecarga. Ajustes por medidas antropométricas não alteraram os resultados, o que ocorreu, porém, após inclusão da variável mudança na insulina nos modelos (artigo original). Conclusão: Justifica-se divulgar programas de intervenção como o aqui desenvolvido considerando-se o atual cenário das doenças cardiometabólicas na atualidade. No presente estudo, o aumento na ingestão de ácidos graxos monoinsaturados e de fibras solúveis promoveu benefícios no metabolismo glicídico, independente da adiposidade, ao final da intervenção no estilo de vida. Possíveis mecanismos mediadores destes processos podem incluir principalmente a melhora da sensibilidade à insulina. Dessa forma, nossos achados sugerem fortemente que um aumento factível no consumo destes nutrientes deva ser estimulado como estratégia para a proteção do metabolismo glicídico em indivíduos de risco cardiometabólico / Introduction: Cardiometabolic diseases are global public health problems with social and economic repercussions. Unhealthy diet is seen as one of the main modifiable risk factors, being of central importance for the prevention of these diseases. Despite the evidence that certain nutrients are associated with diseases, causal relationships are still under discussion. Objectives: 1) To review the involvement of foods and nutrients in the genesis and control of non-communicable chronic diseases, that comprise the metabolic syndrome (manuscript 1); 2) To describe in detail the structure of the interdisciplinary intervention program on lifestyle, developed for costumers of public health system of Sao Paulo city (manuscript 2); 3) To investigate the impact of changes in dietary factors on glucose metabolism, induced by a lifestyle intervention in individuals at cardiometabolic risk attended by the public health system (manuscript 3). Methods: Adults with prediabetes or metabolic syndrome without diabetes were included in a randomized clinical trial involving two types of 18-month interventions: a traditional or an intensive one. The traditional intervention consisted of quarterly consultations with an endocrinologist, while in the intensive participants also attended psychoeducational group sessions with a multidisciplinary team, in addition to the medical visits. The dietary recommendations aimed at the adequate intake of fat (reduction of saturated and trans and increase of unsaturated fatty acids) and increase in fiber intake. Socio-demographic, anthropometric, dietary and biochemical (fasting and post-load plasma glucose, lipid profile, insulin, adiponectin, C-reactive protein, IL-6, TNF-, apolipoprotein A1 and B) data were collected at baseline and after 18-month of follow-up. Diet was assessed by 24-h dietary recalls, processed by Nutrition Data System software. Student t test, correlation coefficients, ANOVA with p for trend and multiple linear regressions analyses were employed to identify dietary factors associated with glucose metabolism improvement. Results: Manuscript 1 consists of a book chapter (Nutrition in Public Health) about epidemiological aspects of diseases of the spectrum of metabolic syndrome with emphasis on dietary factors and nutritional status. Manuscript 2 details the structure, professional team, recommendations and the main psychoeducative strategies used in the lifestyle intervention program developed (methodological article submitted and website). Analyses of manuscript 3 showed that the intervention-induced increase in monounsaturated fatty acids and soluble fiber intake were independently associated with reduction on fasting plasma glucose and the former also with 2h-plasma glucose improvement. Adjustment for anthropometric measurements did not change these results but did after including change in insulin in the models (original article). Conclusion: Intervention programs such as the developed herein should be reported taking into consideration the current scenario of cardiometabolic diseases. In the present study, increases in monounsaturated fatty acids and soluble fiber intake promoted benefits in glucose metabolism, independent of adiposity, at the end of the lifestyle intervention. Possible mechanisms mediating these processes may mainly include improvement in insulin sensitivity. Therefore, our findings strongly suggest that a feasible increase in consumption of these nutrients should be encouraged as a strategy for the protection of glucose metabolism in individuals at cardiometabolic risk

Introdução: Doenças cardiometabólicas são problemas de saúde pública mundial com repercussões sociais e econômicas. Dieta inadequada é apontada como um dos principais fatores de risco modificáveis, de importância central na prevenção destas doenças. Apesar da constatação de que certos nutrientes se associam a doenças, ainda existem dúvidas quanto às relações causais. Objetivos: 1) Revisar a participação dos alimentos e nutrientes na gênese e controle de doenças crônicas não-transmissíveis integrantes da síndrome metabólica (manuscrito 1); 2) Descrever de forma detalhada a estrutura do programa de intervenção interdisciplinar em hábitos de vida, desenvolvido para usuários da rede pública de saúde do município de São Paulo (manuscrito 2); 3) Investigar o efeito de mudanças em fatores dietéticos sobre o metabolismo glicídico, decorrentes de intervenção em hábitos de vida em indivíduos de risco cardiometabólico da rede pública de saúde (manuscrito 3). Métodos: Foram incluídos adultos com diagnóstico de pré-diabetes ou síndrome metabólica sem diabetes em ensaio clínico aleatorizado envolvendo dois tipos de intervenções de 18 meses: tradicional e intensiva. A intervenção tradicional consistiu de consultas trimestrais com endocrinologista; na intensiva, além dos atendimentos médicos, os indivíduos participaram de sessões psicoeducativas em grupo com equipe multiprofissional. As orientações dietéticas visaram à adequação do consumo de gorduras totais (redução de saturadas e trans e elevação de insaturadas) e aumento na ingestão de fibras. As variáveis coletadas nos momentos pré- e pós-intervenção incluíram dados sócio-demográficos, antropométricos, dietéticos e bioquímicos (glicemia de jejum e póssobrecarga, perfil lipídico, insulina, adiponectina, proteína C reativa, IL-6, TNF-, apolipoproteína A1 e B). A dieta foi avaliada por recordatórios de 24 horas, processados pelo Nutrition Data System software. Foram empregados os testes: t de Student, coeficientes de correlações, ANOVA com p de tendência e análises de regressão múltipla para identificar fatores dietéticos associados à melhora do metabolismo glicídico. Resultados: O manuscrito 1 consiste de um capítulo de livro (Nutrição em Saúde Coletiva) abordando aspectos epidemiológicos de doenças do espectro da síndrome metabólica com ênfase em fatores alimentares e estado nutricional. O manuscrito 2 detalha a estrutura, a equipe integrante, as orientações preconizadas e as principais estratégias psicoeducativas utilizadas no programa de intervenção em hábitos de vida desenvolvido (artigo metodológico submetido e website). Análises do manuscrito 3 mostraram que, ao final da intervenção, o aumento na ingestão de ácidos graxos monoinsaturados e fibras solúveis associaramse de forma independente à redução da glicemia de jejum e os primeiros também à melhora da glicemia pós-sobrecarga. Ajustes por medidas antropométricas não alteraram os resultados, o que ocorreu, porém, após inclusão da variável mudança na insulina nos modelos (artigo original). Conclusão: Justifica-se divulgar programas de intervenção como o aqui desenvolvido considerando-se o atual cenário das doenças cardiometabólicas na atualidade. No presente estudo, o aumento na ingestão de ácidos graxos monoinsaturados e de fibras solúveis promoveu benefícios no metabolismo glicídico, independente da adiposidade, ao final da intervenção no estilo de vida. Possíveis mecanismos mediadores destes processos podem incluir principalmente a melhora da sensibilidade à insulina. Dessa forma, nossos achados sugerem fortemente que um aumento factível no consumo destes nutrientes deva ser estimulado como estratégia para a proteção do metabolismo glicídico em indivíduos de risco cardiometabólico / Introduction: Cardiometabolic diseases are global public health problems with social and economic repercussions. Unhealthy diet is seen as one of the main modifiable risk factors, being of central importance for the prevention of these diseases. Despite the evidence that certain nutrients are associated with diseases, causal relationships are still under discussion. Objectives: 1) To review the involvement of foods and nutrients in the genesis and control of non-communicable chronic diseases, that comprise the metabolic syndrome (manuscript 1); 2) To describe in detail the structure of the interdisciplinary intervention program on lifestyle, developed for costumers of public health system of Sao Paulo city (manuscript 2); 3) To investigate the impact of changes in dietary factors on glucose metabolism, induced by a lifestyle intervention in individuals at cardiometabolic risk attended by the public health system (manuscript 3). Methods: Adults with prediabetes or metabolic syndrome without diabetes were included in a randomized clinical trial involving two types of 18-month interventions: a traditional or an intensive one. The traditional intervention consisted of quarterly consultations with an endocrinologist, while in the intensive participants also attended psychoeducational group sessions with a multidisciplinary team, in addition to the medical visits. The dietary recommendations aimed at the adequate intake of fat (reduction of saturated and trans and increase of unsaturated fatty acids) and increase in fiber intake. Socio-demographic, anthropometric, dietary and biochemical (fasting and post-load plasma glucose, lipid profile, insulin, adiponectin, C-reactive protein, IL-6, TNF-, apolipoprotein A1 and B) data were collected at baseline and after 18-month of follow-up. Diet was assessed by 24-h dietary recalls, processed by Nutrition Data System software. Student t test, correlation coefficients, ANOVA with p for trend and multiple linear regressions analyses were employed to identify dietary factors associated with glucose metabolism improvement. Results: Manuscript 1 consists of a book chapter (Nutrition in Public Health) about epidemiological aspects of diseases of the spectrum of metabolic syndrome with emphasis on dietary factors and nutritional status. Manuscript 2 details the structure, professional team, recommendations and the main psychoeducative strategies used in the lifestyle intervention program developed (methodological article submitted and website). Analyses of manuscript 3 showed that the intervention-induced increase in monounsaturated fatty acids and soluble fiber intake were independently associated with reduction on fasting plasma glucose and the former also with 2h-plasma glucose improvement. Adjustment for anthropometric measurements did not change these results but did after including change in insulin in the models (original article). Conclusion: Intervention programs such as the developed herein should be reported taking into consideration the current scenario of cardiometabolic diseases. In the present study, increases in monounsaturated fatty acids and soluble fiber intake promoted benefits in glucose metabolism, independent of adiposity, at the end of the lifestyle intervention. Possible mechanisms mediating these processes may mainly include improvement in insulin sensitivity. Therefore, our findings strongly suggest that a feasible increase in consumption of these nutrients should be encouraged as a strategy for the protection of glucose metabolism in individuals at cardiometabolic risk

Introdução: A prevalência de doenças crônicas tem crescido em decorrência do aumento da obesidade nos últimos anos. Peptídeos secretados pelo trato gastrointestinal, como o peptídeo semelhante ao glucagon 1 (GLP-1) e o peptídeo YY (PYY), exercem papel fundamental no controle da ingestão alimentar, pois levam informações acerca dos nutrientes ingeridos até o sistema nervoso central, possuindo efeitos anorexígenos e/ou orexígenos. Tanto GLP-1 quanto PYY são produzidos pelas células-L do íleo distal e cólon, sendo liberados após a ingestão alimentar. Além do efeito incretina produzido pelo GLP-1, ambos os peptídeos apresentam implicações no controle do apetite, o qual reflete na redução do peso corpóreo. Objetivos: Demonstrar um aumento na secreção de GLP-1 e PYY após sobrecarga oral de diferentes tipos de lipídios, comparados à controle negativo (água) e positivo (glicose). Métodos: Foi realizado um estudo experimental controlado em ratos Wistar, distribuídos em 4 grupos de acordo com a sobrecarga oral: grupo MUFA (óleo de oliva); grupo SAT (banha suína); grupo GLUC (glicose) e grupo CONT (água), foram avaliadas as concentrações séricas de GLP-1 ativo e PYY3-36 nos tempos: 0, 15, 30, 60 e 120 minutos. As sobrecargas foram isovolumétricas e isocalóricas, com exceção do grupo controle. Resultados: Houve pico de secreção do GLP-1 pós-sobrecarga no grupo MUFA no ponto 120’ vs CONT e GLUC (p≤0,001) e no ponto 30’ quando comparado ao seu baseline. Também observou-se pico de secreção de PYY no grupo MUFA vs CONT no ponto 30’ (p=0,015); no ponto 60’ vs CONT e GLUC (p=0,019) e no ponto 120’ vs CONT e SAT (p=0,02). A carga secretada do PYY foi maior no MUFA quando comparada ao CONT (p=0,04). Verificou-se forte correlação entre os níveis basais e AUC’s do GLP-1 e PYY (r=0,57; (p= 0,02); r=0,39; (p≤0,001)). A proporção GLP-1/PYY apresentou um coeficiente médio de 3,77 (±2,04). O grupo MUFA evidenciou níveis menores de glicose e maiores de insulina no ponto 15’, enquanto SAT mostrou níveis maiores de glicose e menores de insulina neste ponto, porém, sem diferença significativa. Conclusão: A sobrecarga oral de fontes de ácidos graxos monoinsaturados promoveu um pico de secreção do GLP-1 de forma rápida e no que diz respeito ao PYY, o pico foi mais sustentado. Estudos adicionais são necessários, a fim de se avalir o efeito de fontes distintas de lipídeos da dieta sobre a secreção destes peptídeos e seus efeitos na saciedade. / Background: The increased prevalence of chronic diseases has risen due to obesity. Gut peptides, such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), play an important role controlling food intake in response to a meal. GLP-1 exerts the known incretin effect stimulating the release of insulin in a glucosedependent manner. Besides its insulinotropic effects, it is well established that GLP-1 slows gastric emptying, and also inhibits inappropriate glucagon release, additionally improves satiety. Both PYY and GLP-1 are produced by L cells of the distal ileum and colon. Objective: Demonstrate an increased secretion of PYY and GLP-1 after oral overload of different types of lipids, compared to negative (water) and positive (glucose) control. Methods: We conducted a controlled experimental study in Wistar rats, divided into 4 groups according to oral overload: MUFA group (olive oil), SAT group (lard:), carbohydrates group (glucose) and CONT group (water), It was evaluated the serum concentration of active GLP-1 and PYY3-36 in the times: 0, 15, 30, 60 and 120 minutes. Overloads were isovolumetric and isocaloric, but the control group. Results: It was verified a higher peak secretion of GLP-1 in MUFA group at 120' after overload vs. CONT and carbohydrates (p ≤ 0.001) and at 30' when compared to its baseline (p=0,01). It was shown a higher secretion peak of GLP-1 after MUFA overload at time 120’ vs CONT e GLUC (p≤0,001) and at time 30’ when compared to its baseline. It was also verified a PYY release peak in MUFA vs CONT at time 30’ (p=0,015); 60’ vs CONT e GLUC (p=0,019) and 120’ vs CONT e SAT (p=0,02). PYY release load presented higher in MUFA group when compared to CONT (p=0,04). A strong correlation was seen between baseline PYY and GLP-1 (r=0,57; p= 0,02) as their AUC’s (r=0,39; p≤0,001). GLP-1/PYY proportion release presented a mean coefficient of 3, 77(±2,04).Conclusion: monounsaturated fatty acids promoted a release peak of GLP-1 in a faster manner and concerning PYY this peak was more sustained. Further studies are necessary to evaluate whether distinct diet fatty acids can ameliorate these gut peptides release and their role on satiety.

Introdução: A prevalência de doenças crônicas tem crescido em decorrência do aumento da obesidade nos últimos anos. Peptídeos secretados pelo trato gastrointestinal, como o peptídeo semelhante ao glucagon 1 (GLP-1) e o peptídeo YY (PYY), exercem papel fundamental no controle da ingestão alimentar, pois levam informações acerca dos nutrientes ingeridos até o sistema nervoso central, possuindo efeitos anorexígenos e/ou orexígenos. Tanto GLP-1 quanto PYY são produzidos pelas células-L do íleo distal e cólon, sendo liberados após a ingestão alimentar. Além do efeito incretina produzido pelo GLP-1, ambos os peptídeos apresentam implicações no controle do apetite, o qual reflete na redução do peso corpóreo. Objetivos: Demonstrar um aumento na secreção de GLP-1 e PYY após sobrecarga oral de diferentes tipos de lipídios, comparados à controle negativo (água) e positivo (glicose). Métodos: Foi realizado um estudo experimental controlado em ratos Wistar, distribuídos em 4 grupos de acordo com a sobrecarga oral: grupo MUFA (óleo de oliva); grupo SAT (banha suína); grupo GLUC (glicose) e grupo CONT (água), foram avaliadas as concentrações séricas de GLP-1 ativo e PYY3-36 nos tempos: 0, 15, 30, 60 e 120 minutos. As sobrecargas foram isovolumétricas e isocalóricas, com exceção do grupo controle. Resultados: Houve pico de secreção do GLP-1 pós-sobrecarga no grupo MUFA no ponto 120’ vs CONT e GLUC (p≤0,001) e no ponto 30’ quando comparado ao seu baseline. Também observou-se pico de secreção de PYY no grupo MUFA vs CONT no ponto 30’ (p=0,015); no ponto 60’ vs CONT e GLUC (p=0,019) e no ponto 120’ vs CONT e SAT (p=0,02). A carga secretada do PYY foi maior no MUFA quando comparada ao CONT (p=0,04). Verificou-se forte correlação entre os níveis basais e AUC’s do GLP-1 e PYY (r=0,57; (p= 0,02); r=0,39; (p≤0,001)). A proporção GLP-1/PYY apresentou um coeficiente médio de 3,77 (±2,04). O grupo MUFA evidenciou níveis menores de glicose e maiores de insulina no ponto 15’, enquanto SAT mostrou níveis maiores de glicose e menores de insulina neste ponto, porém, sem diferença significativa. Conclusão: A sobrecarga oral de fontes de ácidos graxos monoinsaturados promoveu um pico de secreção do GLP-1 de forma rápida e no que diz respeito ao PYY, o pico foi mais sustentado. Estudos adicionais são necessários, a fim de se avalir o efeito de fontes distintas de lipídeos da dieta sobre a secreção destes peptídeos e seus efeitos na saciedade. / Background: The increased prevalence of chronic diseases has risen due to obesity. Gut peptides, such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), play an important role controlling food intake in response to a meal. GLP-1 exerts the known incretin effect stimulating the release of insulin in a glucosedependent manner. Besides its insulinotropic effects, it is well established that GLP-1 slows gastric emptying, and also inhibits inappropriate glucagon release, additionally improves satiety. Both PYY and GLP-1 are produced by L cells of the distal ileum and colon. Objective: Demonstrate an increased secretion of PYY and GLP-1 after oral overload of different types of lipids, compared to negative (water) and positive (glucose) control. Methods: We conducted a controlled experimental study in Wistar rats, divided into 4 groups according to oral overload: MUFA group (olive oil), SAT group (lard:), carbohydrates group (glucose) and CONT group (water), It was evaluated the serum concentration of active GLP-1 and PYY3-36 in the times: 0, 15, 30, 60 and 120 minutes. Overloads were isovolumetric and isocaloric, but the control group. Results: It was verified a higher peak secretion of GLP-1 in MUFA group at 120' after overload vs. CONT and carbohydrates (p ≤ 0.001) and at 30' when compared to its baseline (p=0,01). It was shown a higher secretion peak of GLP-1 after MUFA overload at time 120’ vs CONT e GLUC (p≤0,001) and at time 30’ when compared to its baseline. It was also verified a PYY release peak in MUFA vs CONT at time 30’ (p=0,015); 60’ vs CONT e GLUC (p=0,019) and 120’ vs CONT e SAT (p=0,02). PYY release load presented higher in MUFA group when compared to CONT (p=0,04). A strong correlation was seen between baseline PYY and GLP-1 (r=0,57; p= 0,02) as their AUC’s (r=0,39; p≤0,001). GLP-1/PYY proportion release presented a mean coefficient of 3, 77(±2,04).Conclusion: monounsaturated fatty acids promoted a release peak of GLP-1 in a faster manner and concerning PYY this peak was more sustained. Further studies are necessary to evaluate whether distinct diet fatty acids can ameliorate these gut peptides release and their role on satiety.

Introdução: A prevalência de doenças crônicas tem crescido em decorrência do aumento da obesidade nos últimos anos. Peptídeos secretados pelo trato gastrointestinal, como o peptídeo semelhante ao glucagon 1 (GLP-1) e o peptídeo YY (PYY), exercem papel fundamental no controle da ingestão alimentar, pois levam informações acerca dos nutrientes ingeridos até o sistema nervoso central, possuindo efeitos anorexígenos e/ou orexígenos. Tanto GLP-1 quanto PYY são produzidos pelas células-L do íleo distal e cólon, sendo liberados após a ingestão alimentar. Além do efeito incretina produzido pelo GLP-1, ambos os peptídeos apresentam implicações no controle do apetite, o qual reflete na redução do peso corpóreo. Objetivos: Demonstrar um aumento na secreção de GLP-1 e PYY após sobrecarga oral de diferentes tipos de lipídios, comparados à controle negativo (água) e positivo (glicose). Métodos: Foi realizado um estudo experimental controlado em ratos Wistar, distribuídos em 4 grupos de acordo com a sobrecarga oral: grupo MUFA (óleo de oliva); grupo SAT (banha suína); grupo GLUC (glicose) e grupo CONT (água), foram avaliadas as concentrações séricas de GLP-1 ativo e PYY3-36 nos tempos: 0, 15, 30, 60 e 120 minutos. As sobrecargas foram isovolumétricas e isocalóricas, com exceção do grupo controle. Resultados: Houve pico de secreção do GLP-1 pós-sobrecarga no grupo MUFA no ponto 120’ vs CONT e GLUC (p≤0,001) e no ponto 30’ quando comparado ao seu baseline. Também observou-se pico de secreção de PYY no grupo MUFA vs CONT no ponto 30’ (p=0,015); no ponto 60’ vs CONT e GLUC (p=0,019) e no ponto 120’ vs CONT e SAT (p=0,02). A carga secretada do PYY foi maior no MUFA quando comparada ao CONT (p=0,04). Verificou-se forte correlação entre os níveis basais e AUC’s do GLP-1 e PYY (r=0,57; (p= 0,02); r=0,39; (p≤0,001)). A proporção GLP-1/PYY apresentou um coeficiente médio de 3,77 (±2,04). O grupo MUFA evidenciou níveis menores de glicose e maiores de insulina no ponto 15’, enquanto SAT mostrou níveis maiores de glicose e menores de insulina neste ponto, porém, sem diferença significativa. Conclusão: A sobrecarga oral de fontes de ácidos graxos monoinsaturados promoveu um pico de secreção do GLP-1 de forma rápida e no que diz respeito ao PYY, o pico foi mais sustentado. Estudos adicionais são necessários, a fim de se avalir o efeito de fontes distintas de lipídeos da dieta sobre a secreção destes peptídeos e seus efeitos na saciedade. / Background: The increased prevalence of chronic diseases has risen due to obesity. Gut peptides, such as glucagon-like peptide 1 (GLP-1) and peptide YY (PYY), play an important role controlling food intake in response to a meal. GLP-1 exerts the known incretin effect stimulating the release of insulin in a glucosedependent manner. Besides its insulinotropic effects, it is well established that GLP-1 slows gastric emptying, and also inhibits inappropriate glucagon release, additionally improves satiety. Both PYY and GLP-1 are produced by L cells of the distal ileum and colon. Objective: Demonstrate an increased secretion of PYY and GLP-1 after oral overload of different types of lipids, compared to negative (water) and positive (glucose) control. Methods: We conducted a controlled experimental study in Wistar rats, divided into 4 groups according to oral overload: MUFA group (olive oil), SAT group (lard:), carbohydrates group (glucose) and CONT group (water), It was evaluated the serum concentration of active GLP-1 and PYY3-36 in the times: 0, 15, 30, 60 and 120 minutes. Overloads were isovolumetric and isocaloric, but the control group. Results: It was verified a higher peak secretion of GLP-1 in MUFA group at 120' after overload vs. CONT and carbohydrates (p ≤ 0.001) and at 30' when compared to its baseline (p=0,01). It was shown a higher secretion peak of GLP-1 after MUFA overload at time 120’ vs CONT e GLUC (p≤0,001) and at time 30’ when compared to its baseline. It was also verified a PYY release peak in MUFA vs CONT at time 30’ (p=0,015); 60’ vs CONT e GLUC (p=0,019) and 120’ vs CONT e SAT (p=0,02). PYY release load presented higher in MUFA group when compared to CONT (p=0,04). A strong correlation was seen between baseline PYY and GLP-1 (r=0,57; p= 0,02) as their AUC’s (r=0,39; p≤0,001). GLP-1/PYY proportion release presented a mean coefficient of 3, 77(±2,04).Conclusion: monounsaturated fatty acids promoted a release peak of GLP-1 in a faster manner and concerning PYY this peak was more sustained. Further studies are necessary to evaluate whether distinct diet fatty acids can ameliorate these gut peptides release and their role on satiety.

Plant derived oils bear intrinsic double-bond functionality that can be utilized directly for the thiol–ene reaction. Although terminal unsaturations are far more reactive than internal ones, studies on the reversible addition of thiyl radicals to 1,2-disubstituted alkenes show that this is an important reaction. To investigate the thiol–ene coupling reaction involving these enes, stoichiometric mixtures of a trifunctional propionate thiol with monounsaturated fatty acid methyl esters (methyl oleate or methyl elaidate) supplemented with 2.0 wt.% Irgacure 184 were subjected to 365-nm UV-irradiation and the chemical changes monitored. Continuous (RT– FTIR) and discontinuous (NMR and FT–Raman) techniques were used to follow the progress of the reaction and reveal details of the products formed. Experimental results supported by numerical kinetic simulations of the system confirm the reaction mechanism showing a very fast cis/trans-isomerization of the alkene monomers (&lt;1.0 min) when compared to the total disappearance of double-bonds, indicating that the rate-limiting step controlling the overall reaction is the hydrogen transfer from the thiol involved in the formation of final product. The loss of total unsaturations equals thiol consumption throughout the entire reaction; although product formation is strongly favoured directly from the trans-ene. This indicates that initial cis/trans-isomer structures affect the kinetics. High thiol–ene conversions could be easily obtained at reasonable rates without major influence of side-reactions demonstrating the suitability of this reaction for network forming purposes from 1,2-disubstituted alkenes. To further illustrate the validity of this concept in the formation of cross-linked thiol–ene films a series of globalide/caprolactone based copolyesters differing in degree of unsaturations along the backbone were photopolymerized in the melt with the same trithiol giving amorphous elastomeric materials with different thermal and viscoelastic properties. High thiol–ene conversions (&gt;80%) were easily attained for all cases at reasonable reaction rates, while maintaining the cure behaviour and independent of functionality. Parallel chain-growth ene homopolymerization was considered negligible when compared with the main coupling route. However, the comonomer feed ratio had impact on the thermoset properties with high ene-density copolymers giving networks with higher glass transition temperature values (Tg) and a narrower distribution of cross-links than films with lower ene composition. The thiol–ene systems evaluated in this study serve as model example for the sustainable use of naturally-occurring 1,2-disubstituted alkenes at making semi-synthetic polymeric materials in high conversions with a range of properties in an environment-friendly way. / Vegetabiliska oljor som innehåller dubbelbindningar kan användas direkt för thiolene reaktioner. Trots att terminala dubbelbindningar är mycket mer reaktiva än interna visar dessa studier att den reversibla additionen av thiyl radikaler till 1,2-disubstituerade alkener är en viktig reaktion. För att undersöka tiol–ene reaktionerna, som ivolverar dessa alkener förbereddes stökiometriska blandningar av en trifunktionell propionat tiol och enkelomättade fettsyrametylestrar (metyloleat eller metyl elaidat) samt 2.0 vikt.% Irgacure 184. Dessa blandningar utsattes för 365-nm UV strålning och de kemiska förändringarna studerades. De kemiska förändringarna analyserades med olika kemiska analysmetoder; realtid RT–FTIR, NMR och FT–Raman. Dessa användes för att analysera de kemiska reaktionerna i realtid och följa bildandet av produkterna. Reaktionsmekanismen bekräftades med hjälp av experimentella data och beräkningar av numeriska och kinetiska simuleringar för systemet. Resultaten visar en mycket snabb cis/trans-isomerisering av alkenmonomeren (&lt;1.0 min) jämfört med den totala förbrukningen av dubbelbindningarna, vilket indikerar att det hastighetsbegränsande steget kontrolleras av väteförflyttningen från tiolen till slutprodukten. Förbrukningen av den totala omättade kolkedjan är lika med tiolförbrukningen under hela reaktionen, även om bildandet av produkten gynnas från trans-enen. Detta indikerar att den första cis/trans-isomerstrukturen påverkar kinetiken. Höga tiol-ene utbyten kan enkelt erhållas relativt snabbt utan inverkan av sidoreaktioner. Detta innebär att denna reaktion kan användas som nätverksbildande reaktion för flerfunktionella 1,2-disubstituted alkenmonomerer. Vidare användes fotopolymerisation i smälta på en serie globalid/kaprolaktonbaserade sampolyestrar med varierad grad av omättnad med samma tritiol vilket resulterade i bildandet av amorfa elastomeriska material med olika termiska och viskoelastiska egenskaper. Hög omsättning (&gt;80%) uppnåddes relativt enkelt för samtliga blandningar oberoende av den initiala funktionaliteten. Homopolymerisation av alkenen var försumbar i jämförelse med den tiol–en-reaktionen. Mängden alkengrupper har inverkan på härdplastsegenskaperna där en hög andel alken ger en nätstruktur med högre glastransitionstemperatur (Tg). Tiol–ene reaktionen utvärderades i modellsystem baserade på naturlig förekommande 1,2-disubstituterade alkener för att demonstrera konceptet med tiol-förnätade halvsyntetiska material. / QC 20110915