Introdução: O ambiente obesogênico atual faz com que práticas alimentares não saudáveis, exerçam influência sobre o ganho ponderal na gestação. O ganho de peso excessivo associa-se a várias complicações da gravidez e é um forte preditor de sobrepeso/obesidade das mulheres no pós-parto. Objetivos: 1) - Descrever o consumo alimentar durante a gestação. 2) avaliar sua influência sobre o ganho de peso semanal no segundo e terceiro trimestre. 3) - Avaliar o percentual de ganho ponderal excessivo e insuficiente de acordo com o estado nutricional pré-gestacional, segundo o IOM 2009. Metodologia: Realizou-se estudo de coorte com 195 gestantes adultas, saudáveis, de gestação única e com idade gestacional inicial inferior a 16 semanas. A captação ocorreu em 3 unidades básicas de saúde da região do Butantã, entre abril de 2011 e agosto de 2012. Foram aplicados questionários socioeconômicos, questionário de freqüência alimentar e 2 recordatórios de 24 horas (R24hs) por trimestre de gestação. As medidas antropométricas foram aferidas uma vez em cada trimestre gestacional. O ganho ponderal foi obtido pela diferença entre o peso medido na última e na primeira entrevista (X= 10,7 semanas), expresso como média de ganho semanal. A influência do consumo alimentar sobre o ganho ponderal foi analisada mediante regressão linear simples e múltipla ajustada por potenciais variáveis de confusão. Estimou-se a adequação do ganho semanal de acordo com o estado nutricional pré-gestacional, segundo o IOM 2009. Resultados: No segundo e terceiro trimestres o consumo médio de energia foi de aproximadamente 2200kcal. A gordura saturada apresentou porcentagem igual a 11 por cento , ligeiramente acima do valor recomendado. O consumo médio de gordura trans foi 5.8g em ambos trimestres mais que o dobro do recomendado. A média de consumo de açúcares totais da dieta foi igualmente elevada - cerca de 120g. A maioria das gestantes não atingiu a recomendação diária de frutas, verduras e legumes de 400g/dia. No primeiro trimestre de gestação o consumo médio de energia, gordura saturada, gordura trans, açúcares e refrigerantes foi inferior ao dos demais trimestres. Verificou-se associação positiva entre o ganho de peso semanal os tercis de consumo de energia no segundo e terceiro trimestre de gestação, mesmo após ajuste por IMC pré-gestacional, estatura e escolaridade (p de tendência 0,028 e 0,042, respectivamente). O consumo de gordura saturada mostrou resultado semelhante com p de tendência 0,026 nos dois trimestres. Com relação à gordura trans detectou-se associação positiva com o ganho de peso somente no terceiro trimestre, p de tendência 0,001 (no modelo ajustado). As demais variáveis de consumo alimentar não apresentaram associação significativa com o ganho ponderal. No período pré-gestacional, 34,4 por cento das mulheres apresentaram sobrepeso e 18 por cento obesidade. Foi elevado o percentual de ganho de peso excessivo (63,2 por cento ) e mais freqüente nas gestantes com baixo peso (80 por cento ) seguido por aquelas com sobrepeso inicial (73,8 por cento ). A freqüência de ganho insuficiente foi 12,1 por cento . Conclusão: Os resultados do presente estudo revelam que práticas alimentares inadequadas e ganho ponderal excessivo condizem com a epidemia atual de obesidade. Apontam para a relevância da promoção de práticas alimentares saudáveis durante o pré-natal e de intervenções com visitas a prevenir e controlar o ganho ponderal excessivo durante a gestação / Background: Nowadays, the obesogenic environment is associated with unbalanced food intake have increase excessive weight gains during pregnancy. This high weight gain is related to complications during pregnancy and is a strong predictor of overweight/obesity in women in the postpartum. Objectives: 1) To describe diet during pregnancy 2) To evaluate its relation to maternal weight gain per week in second and third trimesters. 3) To evaluate gestational weight gain in above, appropriate or below according to the 2009 Institute of Medicine (IOM) Guidelines. Methods: Cohort study with 195 pregnant women, 20 years, healthy, singleton pregnancies, under than 16 gestational weeks and recruited from three basic units of Butantã. Recruitment began in April 2011 and ended in August 2012. Women were questioned about socioeconomic status, educational level and presence of a partner. Food frequency questionnaire (FFQ) and the 24h recall were applied, and anthropometric measurements were obtained. This procedure was repeated in the second and third trimester, with the exception of FFQ. The weight gain was obtained by the difference between the weight measured in the first and in the last interview (mean=10.7 weeks), to give us the weekly gestational weight gain. The influence of food intake on weight gain was analyzed by simple and multiple linear regression, adjusted for confounders. The adequacy of weight gain per week was estimated according to nutritional status before pregnancy, as stated by the IOM, 2009 recommendation. Results: In the second and third trimesters, the mean of energy intake was 2200 Kcal. The daily intake of saturated fat was 11 per cent , little upper the limit of recommendation. The mean of total trans fatty acids intake was 5.8g/day. The mean consumption of sugar was also high (120g/day). Almost two-thirds of pregnant women eat less than the recommended amount of fruits and vegetables (400 g/day). In the first trimester, the mean intake of energy, saturated fat, trans fatty acids, sugar and soft drinks were less than others trimesters. The tertiles of energy intake on second and third trimesters were positively associated with maternal weight gain, after adjust for BMI, pre-gestational weight, stature and education (p trend=0.028 and 0.042, respectively). Saturated fat consumption was also positively associated with pregnancy weight gain (p trend=0.026 in second and third trimesters), and trans fatty acids was strongly associated with pregnancy weight gain in the third trimester (p trend=0.001 in the adjusted model). Among other dietary variables and pregnancy weight gain, no significant associations were observed. In pre-gestational period, 34 per cent were overweight and 18 per cent were obese. The incidence of excessive weight gain was 63,2 per cent , and it was more frequent low weight women (80 per cent ) and after in overweight women (73,8 per cent ). The frequency of insufficient weight gain was 12,1 per cent . Conclusion: The results of the present study show that unhealthy diet and excessive weight gain are corresponded with the actual obesity epidemic. They indicate the importance of promoting healthy food practices during antenatal and supporting nutritional interventions to prevent and control the excessive weight gain during pregnancy

Introdução: As doenças cardiovasculares são a principal causa de morte no Brasil e no mundo e apresentam importante contribuição para a carga global de doenças. A dieta tem sido considerada um dos determinantes primários do estado de saúde dos indivíduos, atuando na modulação dos fatores de risco metabólicos para doença cardiovascular. Objetivos: Desenvolver um modelo conceitual para a relação entre fatores de risco metabólicos e investigar sua associação com padrões de dieta de adultos e idosos residentes no município de São Paulo. Métodos: Estudo transversal de base populacional com amostra probabilística de adultos e idosos, residentes em área urbana do município de São Paulo, que participaram do Inquérito de Saúde do Município de São Paulo, realizado em duas fases entre os anos de 2008 e 2011 (estudo ISA Capital 2008). Na primeira fase do estudo, 1.102 adultos e idosos, de ambos os sexos, foram entrevistados no domicílio, por meio da aplicação de questionário estruturado e do recordatório alimentar de 24 horas. Na segunda fase, 642 indivíduos adultos e idosos foram reavaliados quanto ao consumo alimentar por meio da aplicação, por telefone, do segundo recordatório alimentar, e, destes, 592 participaram da coleta domiciliar de amostras de sangue venoso, da medição antropométrica e da aferição da pressão arterial por técnico de enfermagem. Os alimentos relatados em ambos os recordatórios foram agrupados segundo a similaridade do valor nutricional e hábitos alimentares da população, e corrigidos pela variância intrapessoal da ingestão por procedimentos estatísticos da plataforma online Multiple Source Method. Os grupos de alimentos foram analisados por meio de análise fatorial exploratória e confirmatória (manuscrito 1) e por modelos de equações estruturais exploratórios (manuscrito 3), a fim de obter os padrões de dieta. O modelo conceitual da relação entre os fatores de risco metabólicos (leptina sérica, proteína C-reativa de alta sensibilidade sérica, pressão arterial sistólica e diastólica, razão colesterol total/lipoproteína de alta densidade, razão triacilglicerol/lipoproteína de alta densidade, glicemia de jejum plasmática, circunferência da cintura e peso corporal) foi obtido por modelos de equações estruturais estratificados por sexo (manuscrito 2). Por fim, a associação dos padrões de dieta com o modelo conceitual proposto (manuscrito 3) foi investigada por modelos de equações estruturais exploratórios. Índices de qualidade de ajuste foram estimados para avaliar a adequação de todos os modelos. As análises foram realizadas no programa Mplus versão 6.12. Resultados: No manuscrito 1, a análise fatorial exploratória revelou a existência de dois padrões de dieta, os quais apresentaram boa qualidade de ajuste na análise fatorial confirmatória quando aplicados os pontos de corte de cargas fatoriais |0,25| na rotação oblíqua Promax. No manuscrito 2, a relação entre os fatores de risco metabólicos foi diferente entre os sexos. Nas mulheres, a leptina sérica apresentou efeitos indiretos e positivos, mediados pelo peso corporal e pela circunferência da cintura, em todos os fatores de risco avaliados. Já nos homens, a leptina sérica apresentou efeitos diretos e positivos sobre a proteína C-reativa de alta sensibilidade e efeitos indiretos e positivos (mediados pelo peso corporal e pela circunferência da cintura) sobre a razão triacilglicerol/lipoproteína de alta densidade, colesterol total/lipoproteína de alta densidade e glicemia de jejum plasmática. No manuscrito 3, foram obtidos três padrões de dieta, dos quais o Tradicional apresentou relação direta e negativa com a leptina sérica e relação indireta e negativa com o peso corporal e a circunferência da cintura, bem como com os demais fatores de risco metabólicos. Já o padrão Prudente apresentou relação direta e negativa com a pressão arterial sistólica, enquanto o padrão Moderno não se associou aos fatores de risco metabólicos investigados. Conclusão: Diferenças nos padrões de dieta de acordo com o tipo de rotação fatorial empregada foram observadas. A relação entre os fatores de risco metabólicos para doença cardiovascular foi distinta entre homens e mulheres, sendo a leptina um dos possíveis hormônios envolvidos. Os padrões de dieta Tradicional e Prudente associaram-se inversamente com os fatores de risco metabólicos, desempenhando uma importante estratégia de prevenção e controle às doenças cardiovasculares no país. / Introduction: The cardiovascular diseases are the main causes of death in Brazil and worldwide, presenting an important contribution to the global burden of diseases. The diet has been considered one of the primary determinants of the population health, by modulating metabolic risk factors for cardiovascular diseases. Objectives: To develop a conceptual model for the relationship between metabolic cardiovascular disease risk factors and investigate its association with dietary patterns of adults and elderly residents in the city of São Paulo. Methods: This is a population-based cross-sectional study with a probabilistic sample of adults and elderly living in the city of São Paulo, Brazil, whom participated in the Health Survey of São Paulo (HS-SP): a study performed in two stages between 2008 and 2011. In the first stage, a total of 1,102 adults and elderly, both sexes, were interviewed at home by trained interviewers, who applied a structured questionnaire and collected a 24-hour dietary recall. In the second stage, a total of 642 adults and elderly were re-evaluated by the application of the second 24-hour dietary recall by telephone. Of these individuals, a total of 592 underwent a household collection of blood samples, anthropometric measurements, and blood pressure assessment by a nurse assistant. The foods reported in both 24-hour recalls were collapsed into food groups according to nutritional composition and dietary habits of the population, and adjusted for the within-person variation of intake by statistical procedures of the web-based platform Multiple Source Method. The food groups were analyzed by exploratory and confirmatory factorial analysis (manuscript 1) and by exploratory structural equation model (manuscript 3) in order to extract the dietary patterns. The conceptual model for the relationship of the metabolic cardiovascular disease risk factors (serum leptin, serum high-sensitivity C-reactive protein, systolic blood pressure, diastolic blood pressure, total cholesterol/HDL-cholesterol ratio, triacylglycerol/HDL-cholesterol ratio, fasting plasma glucose, waist circumference and body weight) was obtained by a structural equation model stratified by sex (manuscript 2). Finally, the association of dietary patterns with the proposed model (manuscript 3) was investigated by exploratory structural equation model. Goodness-of-fit indexes were estimated to evaluate model fit. All analyzes were executed in Mplus software, version 6.12. Results: In manuscript 1, the exploratory factor analysis extracted two dietary patterns. These patterns exhibited a good model fit in the confirmatory factor analysis with the oblique Promax rotation and the factor loading cut-off |0,25|. In manuscript 2, sex differences in the relationship between metabolic cardiovascular disease risk factors were observed. Among women, serum leptin showed positive and indirect effects by mediation of body weight and waist circumference on all metabolic risk factors evaluated. Differently, among men, serum leptin showed positive and direct effects on high-sensitivity C-reactive protein and positive indirect effects (mediated by body weight and waist circumference) on triacylglycerol/HDL-cholesterol ratio, total cholesterol/HDL-cholesterol ratio and fasting plasma glucose. In manuscript 3, three dietary patterns were extracted, with the Traditional one showing negative and direct association with serum leptin and negative indirect effects on the other metabolic risk factors. The Prudent pattern showed a negative and direct association with systolic blood pressure, while the Modern pattern was not associated with any metabolic risk factors investigated. Conclusion: Differences in dietary patterns were observed according to the factor rotation method applied. The relationship between metabolic cardiovascular disease risk factors was distinct between men and women, with leptin emerging as one of the possible hormones involved. The dietary patterns labeled Traditional and Prudent were inversely associated with metabolic risk factors, playing an important strategy for prevention and control of cardiovascular diseases in this country.

Introdução: O comportamento adotado na adolescência é de extrema importância por ser esta uma fase da vida de aprendizagem e formação. Os costumes adquiridos neste estágio constituirão a base da prática alimentar no futuro. Objetivo: Avaliar a qualidade da dieta e seus fatores associados em adolescentes residentes em regiões do Estado São Paulo. Métodos: Estudo transversal de base populacional de uma amostra de 1584 adolescentes, de ambos os sexos, com idade de 12 a 19 anos e 11 meses, incluídos no Inquérito de Saúde de São Paulo - ISA-SP, realizado em 2001-2002. Amostras probabilísticas em dois estágios, setor censitário e domicílio, foram tomadas de cada uma das quatro áreas estudadas (Distrito do Butantã, região sudoeste da grande São Paulo, municípios de Campinas e Botucatu). As informações sobre as características da população de estudo foram obtidas através de questionário e o consumo alimentar pelo Método Recordatório de 24 horas. A qualidade da dieta foi avaliada através do Índice de Qualidade da Dieta (IQD) adaptado para a realidade local. Foi utilizada análise de regressão linear para avaliar a relação entre o IQD e as variáveis independentes. Resultados: A média do IQD foi de 59,7 pontos. Da população estudada, 97,1% apresentou uma dieta inadequada ou que necessita de melhora, sendo que somente 2,9% dos adolescentes possuíam uma dieta considerada saudável de acordo com o IQD. Os valores médios dos componentes do IQD apresentaram-se mais baixos para frutas, leite e derivados e verduras e legumes. Os adolescentes do sexo masculino, praticantes de exercício físico e que residem em casa ou apartamento, apresentaram os maiores escores do IQD. Na análise de regressão linear múltipla, observou-se que quanto maior a idade, menor o IQD e que adolescentes residentes em casa ou apartamento têm um Índice de Qualidade da Dieta maior que os residentes em barraco ou cortiço, independente da idade e ingestão de energia. Conclusão: A qualidade da dieta está associada a melhores condições socioeconômicas e idade. Conhecendo esses fatores associados é possível adaptar políticas e programas de nutrição para atingir as necessidades desta população, prevenindo, principalmente, as doenças crônicas não transmissíveis na idade adulta. / Introduction: The behavior adopting on adolescence is of extreme importance to be a stage of life of learning and formation. The customs acquired in this stage will constitute the base for dietary behavior in the future.Objective: To evaluated the dietary quality and associated factors amog adolescents living in regions of the State of São Paulo.Methods: Cross-sectional population-based study with a sample of 1584 adolescents of both genders, at the age among 12 and 20 years, who were included in the Houschould Health Survey (ISA - SP), performed in 2001-2002. Probabilistic samples were obtained from multi-stage cluster samples (census tracts and homes) of four areas studied (Butantã District, Southwestern sector of the greater São Paulo region and municipality of Campinas and Botucatu). The data about population characteristics were obtained from questionary and the dietary intake by means of the 24- hour recall method. The dietary quality was measured by means of Health Eating Index (HEI), adapted to local realities. Linear regression analyses were performed to evaluated the relationship between HEI and independent variables.Results: Among the population assessed 97.1% presented a poor diet or a diet that needed of improvement and only 2.9% of adolescents had diet respected helthy agreed with the HEI. Average overall score was 59.7 points. Means scores for the index components were lower to fruits, dairy products and leaves and vegetables. Male adolescents, practitioners of physical exercise and residents of house or apartment, presented the major score of the HEI. In the multiple regression analyses, it was observed that the quality of the diet improve with decrease at the age and the adolescents lived in households or apartments have the major HEI than adolescents residents in shack or tenement slum, independent of the age and energy intake.Conclusion: The dietary quality is associated with higher income and age. Knowledge of these associated factors is possible to adapt politics and programs of nutrition to arrive the population´s needs, preventing , mostly, the chronic diseases no transmissible on adult age.

Objetivo - Avaliar a alimentação consumida na escola, por estudantes de primeira a quarta séries da rede pública de ensino do município de Piracicaba, SP. Métodos Foi desenvolvido estudo transversal com 3527 escolares de 12 escolas distribuídas entre as cinco macro-regiões da área urbana do município. A coleta dos dados foi realizada durante o período letivo de 2004, e para conhecer o consumo alimentar utilizou-se questionário de freqüência alimentar. Este instrumento permitiu investigar o consumo da merenda fornecida pelo Programa Nacional de Alimentação Escolar (PNAE) e o consumo de lanches adquiridos em cantinas ou provenientes de casa. O consumo da merenda foi estudado com base no valor energético diário médio e o consumo de lanches foi descrito e classificado em função do número de porções de alimentos dos grupos dos cereais, frutas e açúcares e gorduras consumidos semanalmente. Por meio da aplicação da técnica de regressão linear múltipla, foi possível conhecer a relação entre o valor energético diário médio da merenda consumida (variável dependente) e variáveis demográficas (sexo, idade e região de localização das escolas), estado nutricional e o consumo de lanches dos grupos dos cereais, frutas e açúcares e gorduras. Resultados A média do valor energético da merenda consumida foi 307,1 kcal, e em geral, foi maior entre os estudantes das escolas localizadas nas regiões menos desenvolvidas do município, do sexo masculino, de menor idade e com baixo índice de massa corporal. Quanto ao consumo de lanches, 60,1% dos escolares referiram consumir alimentos do grupo dos açúcares e gorduras três ou mais vezes por semana, enquanto apenas 11,2% relataram consumir alimentos do grupo das frutas com essa mesma freqüência. As variáveis sexo, idade, região de localização das escolas, estado nutricional e consumo de alimentos do grupo das frutas apresentaram associações estatisticamente significantes com o valor energético diário médio. Conclusões O consumo da merenda escolar variou significativamente entre as distintas regiões do município, sendo que as escolas localizadas nas regiões menos desenvolvidas apresentaram maior consumo. A elevada proporção de consumo de lanches ricos em açúcares e gorduras, associada à pequena freqüência de consumo de frutas, reforça a necessidade de desenvolvimentos de ações educativas direcionadas à alimentação saudável no ambiente escolar, assim como maior oferta de frutas e hortaliças pelo Programa. / Objective -To evaluate the feeding consumed in elementary public schools, for students of the city of Piracicaba, Brazil. Methods - A cross-sectional study was carried in twelve schools distributed between the five macro-regions of the urban area of the city. Data were collected in the schools and interviews were conducted with 3527 students through in the year of 2004. A food frequency questionnaire was used to know the consumption of meals supplied by the National School Meal Program and the consumption of snacks acquired in cafeterias or proceeding from house. The consumption of meals was studied based in the energy value daily mean and the consumption of snacks was described and classified in function of the number of portions of foods of the groups of the cereals, fruits and sugars and fats consumed weekly. Multiple linear regression analyses was applied to know the relation between the energy value daily mean of meal consumed (dependent variable) and demographic variable (sex, age and the region of localization of the schools), nutritional status and the consumption of snacks (groups of the cereals, fruits and sugars and fats). Results - The average of the energy value of meals consumed was 307.1 kcal. In general, it was bigger for the students male, lesser age, with low index of corporal mass and of the schools located in the regions less developed of the city. In relation to the consumption of snacks, 60.1% related to consume foods of the group of the sugars and fats 3 or more times per week, while only 11.2% consumed foods of the group of the fruits with this same frequency. The variable sex, age, region of localization of the schools, nutritional status and consumption of food of the group of the fruits presented statistical significant associations with the energy value daily mean. Conclusions - the consumption of meals supplied by the National School Meal Program varied significantly between the distinct regions of the city, being that the schools located in the regions less developed presented a greater consumption. The rise rate of consumption of snacks rich in sugars and fats, associate to the small frequency of consumption of fruits, strengthens necessity of developments of educative actions with focus for the healthy feeding in the schools, as well as the biggest use of the fruits and vegetables in the National School Meal Program.

En 2015, la revue Nature a publié la plus grande étude d’association pangénomique à ce jour reliant des variants génétiques à l’indice de masse corporelle. Cette étude a mis en avant le rôle du système nerveux central dans la vulnérabilité à l’obésité, et soutient un concept original selon lequel la plasticité cérébrale jouerait un rôle important dans le contrôle de la balance énergétique. Ainsi, des capacités de plasticité cérébrale réduites pourraient favoriser des comportements alimentaires inadaptés, ce qui augmenterait le risque de prise de poids sous pression calorique. Les neurones anorexigènes POMC et les neurones orexigènes AgRP qui composent le système à mélanocortine et qui contrôlent la balance énergétique, conservent effectivement des propriétés de plasticité synaptique dans le cerveau adulte. Celles-ci se manifestent en réponse à des fluctuations hormonales intenses, induites par des manipulations génétiques, chirurgicales ou nutritionnelles drastiques. Cependant le rôle physiologique de cette plasticité synaptique au sein du système à mélanocortine n’a pas encore été démontré. Nos résultats montrent que des phénomènes de plasticité cérébrale sont récapitulés à l’échelle des repas chez la souris, en fonction de l’état prandial, en réponse à des changements métaboliques et hormonaux modérés. En effet, une exposition à 1h de régime standard augmente l’activité électrique des neurones POMC, ce qui est corrélé à une rétractation de la couverture astrocytaire autour des somas POMC, sans changement de configuration synaptique par rapport à l’état préprandial. A l’opposé, une exposition à 1h de régime riche en lipides ne modifie pas l’activité électrique des neurones POMC et n’entraine pas de rétractation de la couverture astrocytaire. De plus, par blocage pharmacologique de l’hyperglycémie post-prandiale, nous avons montré que le glucose était nécessaire pour initier la rétractation gliale post-prandiale. Enfin, par une approche pharmacogénétique, nous avons montré que l’inactivation des astrocytes modifie le comportement alimentaire et diminue la couverture astrocytaire autour des neurones POMC. Ces résultats suggèrent que l’astrocyte jouerait un rôle inhibiteur sur l’activité électrique des neurones POMC et que la rétractation astrocytaire post-prandiale, autour des somas POMC lèverait l’inhibition des neurones POMC et favoriserait la sensation de satiété. Ce mode de régulation ne serait pas déclenché lors d’un repas riche en graisses, ce qui expliquerait le faible pouvoir satiétogène de ce type de repas. / In 2015, Nature published the largest pangenomic association study to date linking genetic variants to body mass index. This study highlighted the role of the central nervous system in vulnerability to obesity and supports an original concept that cerebral plasticity plays an important role in the control of energy balance. Thus, reduced cerebral plasticity capacities could lead to inadequate dietary behaviors, which would increase the risk of weight gain under caloric pressure. The anorectic neurons POMC and the orexigenic neurons AgRP of the melanocortin system, which control the energy balance, actually show synaptic plasticity properties in the adult brain. These phenomena are shown in response to intense hormonal fluctuations induced by drastic genetic, surgical or nutritional manipulations. However, the physiological role of this synaptic plasticity within the melanocortin system has not been demonstrated yet. This study shows that cerebral plasticity phenomena are recapitulated at the meal scale in mice, depending on the prandial state, in response to moderate metabolic and hormonal changes. Indeed, 1 h standard diet exposure increases the electrical activity of the POMC neurons, which is correlated with a retraction of the astrocytic coverage around the POMC somas, with no change in synaptic configuration compared to the preprandial state. In contrast, 1 hour of high fat diet exposure does not modify the electrical activity of the POMC neurons and does not involve retraction of the astrocytic coverage. In addition, by pharmacological blockade of postprandial hyperglycemia, we showed that glucose is required for postprandial glial retraction. Finally, by a pharmacogenetic approach, we have shown that the inactivation of astrocytes modifies the feeding behavior and decreases the astrocytic coverage around the POMC neurons. These results suggest i)that astrocytes would play an inhibitory role on the electrical activity of POMC neurons ii) and that the post-prandial astrocytic retraction around POMC somas might remove inhibition of POMC neurons and might promote the sensation of satiety. This mode of regulation would not be activated during a high-fat meal, which would explain the low satietogenic properties of this type of meal.

La Sclérose Latérale Amyotrophique (SLA) est une maladie neurodégénérative due à la dégénérescence des motoneurones supérieurs et inférieurs. La perte des neurones moteurs entraine une atrophie puis une paralysie progressive des muscles. En plus de la perte musculaire, une perte de poids est importante chez les patients SLA. Ce symptôme apparaît avant les premiers symptômes moteurs et est corrélé avec la survie. Ce défaut du métabolisme énergétique est en partie dû à un hypermétabolisme associé à des problèmes de prise alimentaire. L’hypothalamus est la partie du cerveau contrôlant l’ensemble du métabolisme énergétique. L’objectif de ma thèse a été de caractériser les altérations hypothalamiques dans la SLA. Nous avons tout d’abord mis en évidence une anomalie du système mélanocortine de l’hypothalamus, et montré que cette anomalie était associée à des modifications du comportement alimentaire. Ensuite, nos travaux ont mis en évidence une atrophie de la partie postérieure de l’hypothalamus, comprenant l’aire hypothalamique latérale (LHA), des patients SLA, corrélée à la perte de poids. Finalement, nous démontré que les neurones produisant le MCH, situés dans le LHA, sont atteints dans la SLA et qu’une complémentation en MCH empêche la perte de poids dans un modèle animal de SLA. / Amyotrophic Lateral Sclerosis (ALS) is a major neurodegenerative disease characterised by a loss of upper and lower motor neurons. The loss of motor neurons leads to muscle atrophy and paralysis. Besides motor loss, weight loss is important in ALS patients. This symptom appears before first muscular symptoms and is correlated with survival. This defect of energetic metabolism is partially due to hypermetabolism associated with food intake problems. Hypothalamus is the part of brain controlling the energetic metabolism. The aim of my Ph.D. was to characterise hypothalamic alterations in ALS. First, we have shown a default in the melanocortin system of hypothalamus, and shown that this melanocortin defect correlates with alterations in food intake behaviour. Second, we demonstrated the existence of hypothalamic atrophy in ALS patients in the posterior part of the hypothalamus, including the lateral hypothalamic area (LHA). This atrophy was correlated with weight loss. Finally, we observed that hypothalamic MCH neurons, located in the LHA, are affected in ALS, and that MCH complementation rescues weight loss in a mouse model of ALS.

Le système sérotoninergique central a longtemps été associé au contrôle du comportement alimentaire et à la modulation des effets des drogues psychostimulantes sur le comportement.Le récepteur 5-HT2C est présent dans les centres hypothalamiques et particulièrement dans le noyau arqué dans l’hypothalamus (ARC) qui contrôle la régulation homéostatique de la prise alimentaire. On le retrouve aussi dans l’aire tegmentaire ventrale (VTA), une région importante dans la motivation de plusieurs comportements notamment la consommation alimentaire.Dans cette étude, l’hypothèse testée est, d’une part, que le récepteur 5-HT2C exprimé dans le VTA jouerait un rôle dans le contrôle de l’activité locomotrice induite par l’amphétamine et d’autre part qu’il exercerait son effet hypophagique a travers l’ARC.Des micro-injections localisées dans le VTA et dans l’ARC ont été réalisées afin d’évaluer les effets d’un agoniste sélectif du récepteur 5-HT2C, AR231630, sur l’hyperlocomotion stimulée par l’amphétamine ainsi que sur la prise alimentaire chez le rat.Dans les tests sur l’activité locomotrice, AR231630, lorsque qu’injecté dans la VTA, et non pas dans l’ARC, réduit de façon dose-dépendante l’ambulation provoquée par l’amphétamine.Dans les tests sur le comportement alimentaire, l’injection du composé AR231630 dans l’ARC n’induit pas de réduction de la prise alimentaire, contrairement au VTA.Une expérience suivante montre que les effets inhibants de l’administration périphérique d’AR231630 (5mg/kg) sur l’alimentation sont spécifiquement inversés par un prétraitement dans le VTA avec un antagoniste sélectif du récepteur 5-HT2C, SB242084.Ces résultats suggèrent que les récepteurs 5-HT2C dans le VTA participent à la fois au comportement alimentaire et à la fonction de la récompense, et ce, potentiellement par le même mécanisme. / Central serotonin systems have long been associated with the control of ingestive behavior, and the modulation of behavioral effects of psychostimulants.The 5-HT2C receptor is present in hypothalamic centers particularly the arcuate nucleus (ARC) controlling homeostatic regulation of food intake as well as in the ventral tegmental area (VTA), a region important for motivational aspects of multiple behaviors, including feeding.In the present study, the hypothesis was tested that the 5-HT2CR in the VTA may control amphetamine-evoked locomotor activity and 5-HT2CR in the ARC may regulate food consumption. Localized microinjections into the VTA or into the ARC were used to assess the effects of a highly selective 5-HT2C agonist, AR231630, on the locomotor stimulant effect of amphetamine as well as food intake. In the tests for locomotor activity, AR231630 into the VTA, but not into the ARC, dose-dependently reduced locomotor activity elicited by amphetamine. Unexpectedly, in tests for food intake, intra-ARC injection of AR231630 did not reduce food intake even at doses of 10ug, whereas intra-VTA injection of 10ug AR231630 did. A subsequent experiment determined that the suppressant effect of peripheral administration of AR231630 (5 mg/kg) on feeding was partially reversed by pretreatment with the selective 5-HT2CR antagonist SB242084 into the VTA (5ug). These findings suggest that 5-HT2CR in the VTA participates in both food intake and brain reward function, and possibly through the same pathway.

La metformine, un composé antidiabétique reste de nos jours recommandée comme traitement de première intention pour le diabète de type 2. Ses mécanismes d’action en tant que composé anti-hyperglycémiant sont de plus en plus documentés. En revanche, son action anorexigène et ses cibles centrales demeurent peu étudiées. Par ailleurs, des données croissantes de la littérature semblent indiquer que l’activité physique, souvent associée aux thérapies anti-obésité et antidiabétiques, pourrait accroitre la sensibilité des réseaux neuronaux aux signaux endogènes permettant de réguler la prise alimentaire et le poids corporel. Ceci suggère que l’efficacité des thérapies induisant des modulations d’expression de ces signalisations pourrait être directement augmentée par l’activité physique. Dans le présent travail, nous avons cherché i) à explorer les effets centraux de la metformine chez la souris et ii) à déterminer si l’activité physique pouvait potentialiser les effets de la metformine. L’ensemble de mon travail de thèse, réalisée en partenariat avec la société BIOMEOSTASIS, a permis d’apporter des éléments nouveaux quant aux mécanismes impliqués dans les effets centraux de la metformine et d’identifier la nesfatine-1 comme un acteur potentiel dans les effets anorexigènes de ce composé. / Metformin, an antidiabetic compound, still remains a first-line treatment for type 2 diabetes. The mechanisms by which this compound exerts its antihyperglycemic effect are increasingly documented. However, its anorectic action and central targets remain less studied. Furthermore, increasing data in the literature suggest that physical activity, commonly associated with anti-obesity and anti-diabetic therapies, may increase neural networks’ sensitivity to endogenous signals involved in food intake and body weight control. This suggests that the efficacy of therapies inducing expression modulation of these signals may be directly enhanced by physical activity. In the present study, we sought i) to explore the central effects of metformin in mice and, ii) determine whether physical activity could potentiate the effects of metformin. All my work, in partnership with the company BIOMEOSTASIS brought new elements about mechanisms involved in the central effects of metformin and identified nesfatin-1 as a potential actor for the anorectic effects of this compound.

Background: The purpose of this phenomenological study is to explore the existing research on the determinants and influential factors of eating decisions made by Aboriginal peoples and provide insight from the perspective of Aboriginal peoples living off-reserve in Ottawa, Ontario. Methods: This study was comprised of a convenience sample of 12 Aboriginal individuals from a local Aboriginal community centre. Participants were asked to conduct a personal food diary of their meals for a period of 3 days, followed by a one-on-one semi-structured interview. The interviews were designed to explore: 1) knowledge and perspectives of healthy eating 2) knowledge and perspectives of Health Canada’s Eating Well with Canada’s Food Guide – First Nations, Inuit and Métis, 3) perception of influential factors 4) self-efficacy and 5) common barriers in making food choices. Results: 1) Except for the senior participants, healthy food knowledge did not translate into healthy food choices for most participants; 2) Most participants had not seen a copy of the Eating Well with Canada’s Food Guide – First Nations, Inuit and Métis, and all participants felt they were not influenced by it when making eating decisions; 3) The main themes of influential factors were concluded to be: taste preference, availability, convenience, “had no choice”, health reasons, “easy to make”, low in cost, following a diet or “food schedule,” hunger or thirst, “needed something quick”, nearby location (of store or restaurant), being tired or lazy and being in a routine; 4) Most participants perceived themselves as having control over their eating decisions regardless of situational factors and level of motivation varied between participants; 5) Time, financial constraints, having a busy schedule and being unprepared for meals were identified as possible barriers. Conclusions: Either version of the food guide should be developed into a more flexible and convenient tool such as a mobile application. Local community centres should consider providing workshops in food preparation, and to strengthen skills such as understanding food labels of market foods to ease the transition to living off-reserve. Future Implications: Policy makers at the federal, provincial and municipal levels should work together and strengthen their communication strategies in order to coordinate the development and implementation of future interventions.

Made available in DSpace on 2016-07-18T17:54:17Z (GMT). No. of bitstreams: 1 VANDA_DISSERTACAO_02_07_2012.pdf: 1407112 bytes, checksum: 09cfeadac953b4fffebcadc909097269 (MD5) Previous issue date: 2011-08-11 / This research was carried out to analyze possible consequences of formal learning, in a public grade school of the town Mirante do Paranapanema-SP, in the discipline Physical and Biological Sciences, on the part of eight-grade pupils (nowadays the ninth grade) attending Grade School Cycle II, concerning the food intake and quality of life of the pupils respective families. It is a qualitative research comprising 20 pupils of the grade at issue and their families; three teachers and three managers of that school; a doctor providing care at the health unit of the district where the school is located. The collecting of data was made by means of informal observations which were, subsequently, developed in a systematic way, with registrations in a logbook , in which commentaries, occasional facts, sidebar chats, and events involving participants were recorded. Besides such observations, interviews were held. The results showed that the very fact that the pupils studied the discipline Physical and Biological Sciences, at the eight grade of Grade School, does not have meaningful implications concerning their families food intake habits and health care. One found out that, within the researched universe at issue, TV is their main reference as source of information about health and food intake. To review communication with its pupils and respective families, may be perhaps the course to be followed by the school so that its teachings become more meaningful. / A presente pesquisa objetivou analisar possíveis consequências da aprendizagem escolar, em uma escola pública na cidade de Mirante do Paranapanema - SP, na disciplina Ciências Físicas e Biológicas, de alunos da oitava série (atual nono ano) do Ensino Fundamental Ciclo II, referente à alimentação, saúde e qualidade de vida de suas famílias. Trata-se de uma pesquisa de natureza qualitativa, que contou com a participação de 20 alunos da série especificada e suas respectivas famílias; três professores e três gestores da unidade escolar; um médico que atende no Posto de Saúde localizado no mesmo bairro em que a escola objeto da pesquisa se localiza. A coleta de dados ocorreu mediante observações informais que, posteriormente, desenvolveram-se de modo sistemático, com registros em um diário de bordo , no qual foram anotados comentários, fatos ocasionais, conversas paralelas, acontecimentos que envolvessem os participantes. Além das observações, foram realizadas entrevistas. Os resultados indicaram que o fato de os filhos cursarem a disciplina Ciências Físicas e Biológicas, na 8ª série do Ensino Fundamental, não tem implicações significativas quanto a hábitos alimentares e cuidados com a saúde de seus familiares. Verificou-se, no universo pesquisado, que a TV é a principal referência das famílias para informações sobre saúde e alimentação. Repensar sua comunicação com os alunos e com as famílias, talvez seja o caminho a ser seguido pela escola para que seus ensinamentos se tornem mais significativos.