The role of gut hormones in the regulation of appetite and food intake is well established. The studies presented within this thesis have examined the effects of exercise and different environmental conditions on gut hormones (acylated ghrelin and total peptide YY), appetite and food intake. Forty-two young (mean ± SEM; 22.6 ± 0.4 y), healthy and generally lean (body mass index 23.7 ± 0.3 kg m2) males were recruited into four studies. In study one, 60 minutes of high intensity (70 % of O2 max) running and cycling exercise suppressed concentrations of the appetite-stimulating hormone acylated ghrelin to a similar extent. Study two revealed that after 60 minutes running in the heat (30 °C), hunger is lower in the pre-prandial period, and energy intake lower over the 7 h trial duration compared with a similar trial conducted in temperate (20 °C) conditions. Acylated ghrelin was suppressed during running in the temperate and hot environment but this did not appear to mediate the lower energy intake observed during the hot trial. In study three, energy intake tended to be higher after 60 minutes running in a cool environment (10 °C) compared with a temperate (20 °C) environment. During and shortly after running in the cold, perceived ratings of fullness and satisfaction were lower. Acylated ghrelin concentrations appeared to be suppressed to a lesser extent during running in the cold which could mediate the elevated energy intake observed at the first meal. However, energy intake was also higher at the second meal in the cold trial when acylated ghrelin concentrations were higher in the temperate trial. Study four showed that energy intake and acylated ghrelin concentrations were lower, and total PYY tended to be lower, in normobaric hypoxia suggesting a possible role for acylated ghrelin, but not PYY, in mediating the decrease in energy intake observed in hypoxia. This thesis confirms that exercise transiently suppresses acylated ghrelin concentrations regardless of the environmental conditions (temperature and altitude) exercise is performed in. The findings support anecdotal reports that appetite and energy intake are suppressed in the heat and stimulated in the cold. These responses may be partly mediated by acylated ghrelin immediately after running but other mechanisms are likely involved thereafter. Acute hypoxic exposure suppresses acylated ghrelin concentrations; an observation which may explain the decreased energy intake in hypoxia.

A obesidade é caracterizada como uma doença crônica na qual há excesso de massa corporal na forma de gordura, resultando em um grande risco de comorbidades. A saúde humana depende da regulação do metabolismo energético, isto é, a relação entre o consumo alimentar e o gasto energético, processo este de integração entre o Sistema Nervoso Central (SNC) e os órgãos periféricos. Alguns estímulos parecem provocar alterações nas concentrações de Nesfatin-1 (NES1) e Grelina Acilada (GRE), peptídeos envolvidos na homeostase energética, como a obesidade, dieta/refeição hiperlipídica e exercício físico. Assim, o objetivo principal do estudo foi verificar e comparar o efeito agudo do exercício aeróbio sobre o apetite e as concentrações plasmáticas de Grelina Acilada e Nesfatin-1 em homens eutróficos e obesos. Na revisão da literatura, os métodos empregados foram pesquisa bibliográfica, culminado com um artigo de hipótese sobre o tema. No estudo original, onze indivíduos eutróficos (EUT) e dez obesos (OB), sedentários, participaram de 2 protocolos: Controle (Con) e Exercício (Ex). No Ex, os participantes pedalaram durante 45 minutos a 50% do VO2max e, logo após, receberam uma refeição hiperlipídica e permaneceram em repouso por mais 120 minutos. No Con, os participantes ficaram em repouso durante todo o período. Cinco coletas sanguíneas foram realizadas, em cada protocolo. Os níveis de GRE, NES1, triglicerídeos (TG), colesterol total (CT), HDL, LDL e glicose foram mensurados. O apetite (sensação de fome) foi avaliado por meio de uma escala visual. O exercício foi capaz de suprimir os níveis de GRE e apetite nos EUT, mas não nos OB, logo após a sessão. Não houve alteração de NES1 ao longo dos protocolos. Houve uma correlação inversa entre as concentrações plasmáticas em jejum de GRE e NES1 (somente nos EUT) e associação positiva de NES1 com IMC (para ambos os grupos). Este estudo mostrou que o exercício aeróbio agudo induziu supressão de GRE e do apetite em EUT, o que não ocorre em OB. Deste modo, refeições contendo grandes quantidades de gorduras devem ser desencorajadas nesta população. / Obesity is characterized as a chronic disease which there is an excess of body mass as fat, resulting in a greater risk of comorbidities. Human health depends on the regulation of energy metabolism, i.e. the relationship between food intake and energy expenditure, an integration process between the Central Nervous System (CNS) and peripheral organs. Some stimuli, such as obesity, high fat meal/diet, exercise, cause changes in concentrations of peptides involved in energy homeostasis, such as Nesfatin-1 (NES1) and Acylated Ghrelin (GRE). Thus, the main objective of the study was to determine and compare the acute effect of aerobic exercise on appetite and plasma concentrations of acylated ghrelin and nesfatin-1 in normal weight and obese men. In the literature review, the methods employed were bibliographic research, culminating in a hypothesis article about the topic. In the original study, eleven normal weight (EUT) and ten obese (OB), sedentary, participated in two protocols: control (Con) and exercise (Ex). In Ex, they cycled for 45 minutes at 50% VO2max, and soon after, received a high-fat meal and remained resting for over 120 minutes. In Con, the participants were at rest throughout the whole period. Five blood samples were taken in each protocol. The levels of GRE, NES1, triglycerides (TG), total cholesterol (TC), HDL-cholesterol, LDL-cholesterol and glucose were determined. Appetite (hunger sensation) was assessed using a visual scale. The exercise induced suppression of GRE and appetite levels in EUT but not in OB after the session. There was no change in NES1 over protocols. There was an negative correlation between fasting plasma concentrations of NES1 and GRE (only in EUT) and a positive association with BMI and NES1 (for both groups). This study showed that acute aerobic exercise induced suppression of appetite and GRE in EUT, which does not occur in OB. Thus, meals containing high amounts of fats in this population should be discouraged.

A obesidade é caracterizada como uma doença crônica na qual há excesso de massa corporal na forma de gordura, resultando em um grande risco de comorbidades. A saúde humana depende da regulação do metabolismo energético, isto é, a relação entre o consumo alimentar e o gasto energético, processo este de integração entre o Sistema Nervoso Central (SNC) e os órgãos periféricos. Alguns estímulos parecem provocar alterações nas concentrações de Nesfatin-1 (NES1) e Grelina Acilada (GRE), peptídeos envolvidos na homeostase energética, como a obesidade, dieta/refeição hiperlipídica e exercício físico. Assim, o objetivo principal do estudo foi verificar e comparar o efeito agudo do exercício aeróbio sobre o apetite e as concentrações plasmáticas de Grelina Acilada e Nesfatin-1 em homens eutróficos e obesos. Na revisão da literatura, os métodos empregados foram pesquisa bibliográfica, culminado com um artigo de hipótese sobre o tema. No estudo original, onze indivíduos eutróficos (EUT) e dez obesos (OB), sedentários, participaram de 2 protocolos: Controle (Con) e Exercício (Ex). No Ex, os participantes pedalaram durante 45 minutos a 50% do VO2max e, logo após, receberam uma refeição hiperlipídica e permaneceram em repouso por mais 120 minutos. No Con, os participantes ficaram em repouso durante todo o período. Cinco coletas sanguíneas foram realizadas, em cada protocolo. Os níveis de GRE, NES1, triglicerídeos (TG), colesterol total (CT), HDL, LDL e glicose foram mensurados. O apetite (sensação de fome) foi avaliado por meio de uma escala visual. O exercício foi capaz de suprimir os níveis de GRE e apetite nos EUT, mas não nos OB, logo após a sessão. Não houve alteração de NES1 ao longo dos protocolos. Houve uma correlação inversa entre as concentrações plasmáticas em jejum de GRE e NES1 (somente nos EUT) e associação positiva de NES1 com IMC (para ambos os grupos). Este estudo mostrou que o exercício aeróbio agudo induziu supressão de GRE e do apetite em EUT, o que não ocorre em OB. Deste modo, refeições contendo grandes quantidades de gorduras devem ser desencorajadas nesta população. / Obesity is characterized as a chronic disease which there is an excess of body mass as fat, resulting in a greater risk of comorbidities. Human health depends on the regulation of energy metabolism, i.e. the relationship between food intake and energy expenditure, an integration process between the Central Nervous System (CNS) and peripheral organs. Some stimuli, such as obesity, high fat meal/diet, exercise, cause changes in concentrations of peptides involved in energy homeostasis, such as Nesfatin-1 (NES1) and Acylated Ghrelin (GRE). Thus, the main objective of the study was to determine and compare the acute effect of aerobic exercise on appetite and plasma concentrations of acylated ghrelin and nesfatin-1 in normal weight and obese men. In the literature review, the methods employed were bibliographic research, culminating in a hypothesis article about the topic. In the original study, eleven normal weight (EUT) and ten obese (OB), sedentary, participated in two protocols: control (Con) and exercise (Ex). In Ex, they cycled for 45 minutes at 50% VO2max, and soon after, received a high-fat meal and remained resting for over 120 minutes. In Con, the participants were at rest throughout the whole period. Five blood samples were taken in each protocol. The levels of GRE, NES1, triglycerides (TG), total cholesterol (TC), HDL-cholesterol, LDL-cholesterol and glucose were determined. Appetite (hunger sensation) was assessed using a visual scale. The exercise induced suppression of GRE and appetite levels in EUT but not in OB after the session. There was no change in NES1 over protocols. There was an negative correlation between fasting plasma concentrations of NES1 and GRE (only in EUT) and a positive association with BMI and NES1 (for both groups). This study showed that acute aerobic exercise induced suppression of appetite and GRE in EUT, which does not occur in OB. Thus, meals containing high amounts of fats in this population should be discouraged.

A obesidade é caracterizada como uma doença crônica na qual há excesso de massa corporal na forma de gordura, resultando em um grande risco de comorbidades. A saúde humana depende da regulação do metabolismo energético, isto é, a relação entre o consumo alimentar e o gasto energético, processo este de integração entre o Sistema Nervoso Central (SNC) e os órgãos periféricos. Alguns estímulos parecem provocar alterações nas concentrações de Nesfatin-1 (NES1) e Grelina Acilada (GRE), peptídeos envolvidos na homeostase energética, como a obesidade, dieta/refeição hiperlipídica e exercício físico. Assim, o objetivo principal do estudo foi verificar e comparar o efeito agudo do exercício aeróbio sobre o apetite e as concentrações plasmáticas de Grelina Acilada e Nesfatin-1 em homens eutróficos e obesos. Na revisão da literatura, os métodos empregados foram pesquisa bibliográfica, culminado com um artigo de hipótese sobre o tema. No estudo original, onze indivíduos eutróficos (EUT) e dez obesos (OB), sedentários, participaram de 2 protocolos: Controle (Con) e Exercício (Ex). No Ex, os participantes pedalaram durante 45 minutos a 50% do VO2max e, logo após, receberam uma refeição hiperlipídica e permaneceram em repouso por mais 120 minutos. No Con, os participantes ficaram em repouso durante todo o período. Cinco coletas sanguíneas foram realizadas, em cada protocolo. Os níveis de GRE, NES1, triglicerídeos (TG), colesterol total (CT), HDL, LDL e glicose foram mensurados. O apetite (sensação de fome) foi avaliado por meio de uma escala visual. O exercício foi capaz de suprimir os níveis de GRE e apetite nos EUT, mas não nos OB, logo após a sessão. Não houve alteração de NES1 ao longo dos protocolos. Houve uma correlação inversa entre as concentrações plasmáticas em jejum de GRE e NES1 (somente nos EUT) e associação positiva de NES1 com IMC (para ambos os grupos). Este estudo mostrou que o exercício aeróbio agudo induziu supressão de GRE e do apetite em EUT, o que não ocorre em OB. Deste modo, refeições contendo grandes quantidades de gorduras devem ser desencorajadas nesta população. / Obesity is characterized as a chronic disease which there is an excess of body mass as fat, resulting in a greater risk of comorbidities. Human health depends on the regulation of energy metabolism, i.e. the relationship between food intake and energy expenditure, an integration process between the Central Nervous System (CNS) and peripheral organs. Some stimuli, such as obesity, high fat meal/diet, exercise, cause changes in concentrations of peptides involved in energy homeostasis, such as Nesfatin-1 (NES1) and Acylated Ghrelin (GRE). Thus, the main objective of the study was to determine and compare the acute effect of aerobic exercise on appetite and plasma concentrations of acylated ghrelin and nesfatin-1 in normal weight and obese men. In the literature review, the methods employed were bibliographic research, culminating in a hypothesis article about the topic. In the original study, eleven normal weight (EUT) and ten obese (OB), sedentary, participated in two protocols: control (Con) and exercise (Ex). In Ex, they cycled for 45 minutes at 50% VO2max, and soon after, received a high-fat meal and remained resting for over 120 minutes. In Con, the participants were at rest throughout the whole period. Five blood samples were taken in each protocol. The levels of GRE, NES1, triglycerides (TG), total cholesterol (TC), HDL-cholesterol, LDL-cholesterol and glucose were determined. Appetite (hunger sensation) was assessed using a visual scale. The exercise induced suppression of GRE and appetite levels in EUT but not in OB after the session. There was no change in NES1 over protocols. There was an negative correlation between fasting plasma concentrations of NES1 and GRE (only in EUT) and a positive association with BMI and NES1 (for both groups). This study showed that acute aerobic exercise induced suppression of appetite and GRE in EUT, which does not occur in OB. Thus, meals containing high amounts of fats in this population should be discouraged.

A manutenção da saúde, depende, dentre outros aspectos, do controle da massa corporal, uma vez que a obesidade está associada ao desenvolvimento de doenças crônicas. Sendo assim, o exercício pode ser considerado uma ferramenta eficaz nesse controle. Contudo, está evidenciado que o exercício realizado em alta intensidade pode ocasionar maior redução da gordura corporal. Dentre as hipóteses sugeridas para explicar tal fenômeno, a supressão do apetite pós-exercício foi levantada, no entanto, o efeito da intensidade sobre o apetite ainda é incipiente. Além disso, mulheres podem ter maior resposta compensatória que homens. Portanto, o objetivo do estudo foi comparar o efeito da intensidade no controle agudo do apetite, energia ingerida absoluta e relativa (energia ingerida menos o gasto calórico do exercício), percepção de fome e das concentrações sanguíneas de grelina acilada, peptídeo YY3-36, insulina, cortisol, glicose, ácidos graxos, colesterol e triacilglicerol em homens e mulheres. Para isso, 11 homens e 9 mulheres eutróficos, foram submetidos a 6 sessões, sendo a primeira destinada à determinação da potência aeróbia máxima (PAM) em cicloergômetro, e a segunda para realização do exercício intermitente de alta intensidade realizado na máxima intensidade (all out), composto por 60 x 8s:12s (EIAI-A), para determinação do trabalho total, o qual foi utilizado para equalização das demais sessões: a) EIAI-A; b) exercício intermitente de alta intensidade (EIAI) - 60s:60s a 100% da PAM; c) exercício contínuo de intensidade moderada (ECMI) a 60% da PAM; d) sessão controle (sem exercício). Cada visita teve duração de 4h, sendo que os participantes chegaram em jejum e receberam um café da manhã padrão. O exercício foi realizado 1,5h pós-café da manhã, e uma alimentação ad libitum foi servida 4h pós-café da manhã. Coletas de sangue e da percepção de fome (escala analógica visual) foram realizadas em jejum e em 2, 2,5, 3,25 e 4h de experimento e calculada a área sob a curva (ASC) para cada uma dessas variáveis. A comparação das variáveis sanguíneas e da percepção de fome foi feita através de análise de variância a três fatores (condição, sexo e momento), e das variáveis envolvendo a ASC e a energia ingerida foi conduzida através de análise a dois fatores (condição e sexo), seguida do pós-teste de Bonferroni se observada diferença significativa (P<0,05). Não houve diferença para a energia ingerida absoluta, porém, a energia ingerida relativa foi maior no controle quando comparada ao EIAI-A, EIAI, e ao ECMI, sem diferenças entre os tipos de exercício e sexos. A ASC da percepção de fome foi menor somente nos exercícios realizados em alta intensidade comparado com o controle, independentemente do sexo. O PYY3-36 foi inferior nas mulheres em relação aos homens ao passo que o cortisol foi inferior nos homens comparado com as mulheres. Houve interação entre situação e momento de coleta para o cortisol e insulina sendo os valores mais elevados no EIAI-A que no controle às 2,5 horas de experimento para o cortisol e às 3,25h para insulina. Portanto, embora não tenha havido diferença na energia ingerida relativa entre os tipos de exercícios, àqueles realizados em maior intensidade foram capazes de promover efeitos mais pronunciados na supressão do apetite, independentemente do sexo / Maintaining one\'s health depends, among other things, on controlling body weight, since obesity is associated with the development of chronic diseases. Accordingly, exercise is an effective tool in this control. It has been demonstrated that exercise performed at a high intensity can cause greater reduction in body fat. Among the hypotheses put forward of this phenomenon is the suppression of appetite. However, the understanding of the effect of the intensity on appetite is still incipient. In addition, women may have a greater compensatory response than men. Therefore, the aim of the study was to compare the effect of intensity on absolute and relative (energy intake less caloric expenditure of the exercise) energy intake, hunger and blood concentrations of acylated ghrelin, PYY3-36, insulin, cortisol, glucose, fatty acids, cholesterol and triacylglycerol in men and women. Accordingly, 11 men and 9 women, all eutrophic, underwent six sessions. The first was designed to determine their maximum aerobic power (MAP) on a cycle ergometer, and the second involved performing high-intensity intermittent exercise at maximum intensity (all out) for 60 x 8s: 12s (HIIE-A) in order to determine the total work, which was used for the equalization of the other sessions: a) HIIE-A; b) high intensity intermittent exercise (HIIE) - 60s: 60s at 100% of MAP; c) steady-state exercise (SSE) at 60% of the MAP; d) a control session. Each session lasted a total of 4 hours. The participants arrived in fasting and received a standard breakfast upon arrival. The exercise session was performed 1.5 h after breakfast, and an ad libitum meal was served 4 hours post-breakfast. Blood sample collection and perception of hunger were collected when fasting and at 2, 2.5, 3.25 and 4 hours into the experiment and the area under the curve (AUC) for each of these variables was calculated. A comparison of the blood sample variables and rating of hunger was performed by analyzing the variance of three factors (condition, sex, and time) and the analysis of the variables involving the AUC and energy intake was conducted through examination of two factors (sex and condition) followed by a Bonferroni post-test if significant differences (P<0.05) were observed. There was no difference for the absolute energy intake, however, relative energy intake was higher in the control compared to HIIE-A, HIIE, and SSE, with no differences between the types of exercise and sex. The AUC of hunger was lower in exercises performed at high intensity when compared to the control, regardless of sex. There was interaction between condition and time for cortisol and insulin, with higher levels in the HIIE-A than in the control at 2.5 hours for cortisol and 3.25 hours for insulin. Therefore, although there were no differences in energy intake relative to the types of exercises, those performed at a higher intensity promoted more pronounced effects on appetite suppression, regardless of sex

Recent years have witnessed significant research into the acute effects of exercise on appetite, energy intake and gut hormone responses. The experiments in this thesis have further investigated this topic by examining the appetite, acylated ghrelin, peptide YY and energy intake responses to energy deficits induced via different exercise protocols and food restriction. To achieve this, 48 young healthy males (mean (SD): age 23 (3) years, body mass index 23.7 (2.7) kg.m-2, maximum oxygen uptake 52.9 (9.8) mL.kg 1.min-1) were recruited into four studies. In study one, 60 min of treadmill running at 70% of VO2 max did not stimulate any increases in appetite or daily energy intake regardless of whether the exercise was performed after breakfast or in the fasted state. In study two, six 30 s Wingate tests stimulated increases in appetite during the subsequent hours compared with 60 min of cycling at 68% of VO2 max. Differences in appetite appeared to be unrelated to changes in plasma acylated ghrelin concentrations and did not influence ad libitum energy intake. Subsequently, endurance exercise resulted in a significantly greater negative daily energy balance than sprint exercise due to a larger exercise energy expenditure. Study three revealed that appetite and energy intake did not differ from a resting control trial after either ten, 4 min cycling bouts at 85 90% of VO2 max separated by 2 min of rest or 60 min of constant cycling at 60% of VO2 max. This occurred despite elevated PYY3-36 concentrations during the hours after exercise. Finally, study four showed that an energy deficit of ~1475 kJ stimulated increases in appetite when induced via food restriction but not when achieved by an acute bout of exercise. This was associated with differences in plasma PYY3-36 concentrations but did not appear to be related to changes in circulating levels of acylated ghrelin and did not influence energy intake. This thesis has shown that appetite perceptions do not differ from a resting control trial during the hours after continuous endurance exercise. Alternatively, supramaximal cycling exercise and subtle reductions in food intake stimulated increases in appetite during the subsequent hours. Such increases in appetite do not appear to be related to changes in acylated ghrelin but may be influenced by plasma PYY3-36 concentrations. Despite differences in appetite, daily energy intake was unaffected by all interventions.

The acute effects of exercise on appetite, ad libitum energy intake and gut hormone responses have received much attention over the past two decades. The experiments in this thesis have contributed to this research by examining appetite, acylated ghrelin, peptide-YY (PYY), leptin and ad libitum energy intake responses to two consecutive days of moderate-high intensity running. To achieve this 15 individuals aged 21 (2) y, with a BMI of 23.0 (1.9) kg·m-2 were recruited. Additionally, appetite, acylated ghrelin, PYY, glucagon-like peptide-1 (GLP-1), and ad libitum energy intake responses to an acute bout of moderate intensity treadmill exercise were compared in lean and overweight/obese (ow/ob) males and females. Two separate cohorts of individuals were recruited; 22 lean individuals and 25 ow/ob individuals (aged 38 (15) and 45 (12) y, with a BMI of 22 (2) and 29 (3) kg·m 2, for lean and ow/ob individuals, respectively). In Chapter 4, two consecutive days of 60 min treadmill running at 70% VO₂ peak did not produce compensatory changes in appetite or energy intake over two days. There were no main effects of trial for acylated ghrelin or leptin. However a main effect of trial for PYY indicated higher concentrations on the exercise than control trial. A meta-analysis was completed in Chapter 5, suggesting further research in the effects of acute exercise on appetite regulatory hormones in individuals who are ow/ob was necessary. In Chapter 6, 60 min of treadmill exercise at 60% VO₂ peak did not alter appetite sensations or energy intake in the 7 h after exercise in lean and ow/ob males and females. There were no main effects of sex, BMI or trial for acylated ghrelin; however, PYY and GLP-1 concentrations were higher in exercise than control trials. This thesis has demonstrated that over two days, high volume exercise does not stimulate compensatory appetite regulatory changes, in lean healthy males. In the short term, lean and ow/ob males and females respond similarly to acute exercise, showing no alterations in appetite or food intake responses, whilst PYY and GLP-1 concentrations are higher in exercise than control trials.

Current methods of energy restriction are not successful for achieving long-term weight loss and maintenance for the majority of individuals. As a result, the prevalence of obesity and obesity related diseases continue to increase. This calls for the development of novel lifestyle interventions to combat the obesity epidemic. Hunger has been highlighted as a major factor influencing the long-term success of weight management methods and therefore how a given dietary intervention affects the appetite regulatory system may dictate the success of the diet by augmenting long-term adherence. In addition, the effect of a given dietary intervention on exercise may determine its suitability for exercising individuals and may influence the energy deficit that can be achieved by the diet. This thesis investigated the acute effects of two novel methods of dietary restriction; breakfast omission and severe energy restriction. The main aims for this thesis were to determine the effect of these methods of energy restriction on ad-libitum energy intake, subjective appetite sensations, and peripheral concentrations of hormones involved in appetite regulation. In addition, this thesis also investigated the effects of these methods of energy restriction on metabolism and glycaemic control at rest, and performance and perceived exertion during exercise. This work found that moderate and severe energy deficits induced by breakfast omission and 24 h of severe energy restriction, respectively, resulted in either no (Chapter VIII) or partial (Chapters IV and VII) energy intake compensation over the subsequent 24-48 h. Subjective appetite was increased during (Chapters IV, V, VII and VIII) and shortly after (Chapter VII) energy restriction, but this effect was transient and was offset after an ad-libitum (Chapters IV and VII) or standardised (Chapters V and VIII) meal. In addition, none of the work presented in this thesis demonstrated an appetite hormone response to energy restriction that was indicative of compensatory eating behaviour. Compared to breakfast omission, breakfast consumption resulted in an increased in resting energy expenditure and carbohydrate oxidation, with a concurrent reduction in fat oxidation during the morning. However, there were no differences after lunch (Chapter V). In response to a standardised breakfast, resting energy expenditure was suppressed (Chapter VII) or not different (Chapter VIII) the following morning, after 24 h severe energy restriction compared to energy balance. Plasma NEFA and fat oxidation was greater, carbohydrate oxidation was reduced, and postprandial insulin sensitivity was impaired in the after 24 h severe energy restriction (Chapter VI, VII and VIII). In Chapter IV, omission of breakfast in the morning was shown to reduce exercise performance in evening, even after provision of an ad-libitum lunch 4 h before. However, there was no difference in perception of effort during steady state exercise, independent of breakfast consumption or omission in the morning (Chapters IV and V). Collectively, breakfast omission and 24 h severe energy restriction reduce energy intake and promote an appetite regulatory response conducive to maintenance of a negative energy balance. Chronic intervention studies are now required to confirm whether these effects persist after long-term practice of these dietary interventions.

A manutenção da saúde, depende, dentre outros aspectos, do controle da massa corporal, uma vez que a obesidade está associada ao desenvolvimento de doenças crônicas. Sendo assim, o exercício pode ser considerado uma ferramenta eficaz nesse controle. Contudo, está evidenciado que o exercício realizado em alta intensidade pode ocasionar maior redução da gordura corporal. Dentre as hipóteses sugeridas para explicar tal fenômeno, a supressão do apetite pós-exercício foi levantada, no entanto, o efeito da intensidade sobre o apetite ainda é incipiente. Além disso, mulheres podem ter maior resposta compensatória que homens. Portanto, o objetivo do estudo foi comparar o efeito da intensidade no controle agudo do apetite, energia ingerida absoluta e relativa (energia ingerida menos o gasto calórico do exercício), percepção de fome e das concentrações sanguíneas de grelina acilada, peptídeo YY3-36, insulina, cortisol, glicose, ácidos graxos, colesterol e triacilglicerol em homens e mulheres. Para isso, 11 homens e 9 mulheres eutróficos, foram submetidos a 6 sessões, sendo a primeira destinada à determinação da potência aeróbia máxima (PAM) em cicloergômetro, e a segunda para realização do exercício intermitente de alta intensidade realizado na máxima intensidade (all out), composto por 60 x 8s:12s (EIAI-A), para determinação do trabalho total, o qual foi utilizado para equalização das demais sessões: a) EIAI-A; b) exercício intermitente de alta intensidade (EIAI) - 60s:60s a 100% da PAM; c) exercício contínuo de intensidade moderada (ECMI) a 60% da PAM; d) sessão controle (sem exercício). Cada visita teve duração de 4h, sendo que os participantes chegaram em jejum e receberam um café da manhã padrão. O exercício foi realizado 1,5h pós-café da manhã, e uma alimentação ad libitum foi servida 4h pós-café da manhã. Coletas de sangue e da percepção de fome (escala analógica visual) foram realizadas em jejum e em 2, 2,5, 3,25 e 4h de experimento e calculada a área sob a curva (ASC) para cada uma dessas variáveis. A comparação das variáveis sanguíneas e da percepção de fome foi feita através de análise de variância a três fatores (condição, sexo e momento), e das variáveis envolvendo a ASC e a energia ingerida foi conduzida através de análise a dois fatores (condição e sexo), seguida do pós-teste de Bonferroni se observada diferença significativa (P<0,05). Não houve diferença para a energia ingerida absoluta, porém, a energia ingerida relativa foi maior no controle quando comparada ao EIAI-A, EIAI, e ao ECMI, sem diferenças entre os tipos de exercício e sexos. A ASC da percepção de fome foi menor somente nos exercícios realizados em alta intensidade comparado com o controle, independentemente do sexo. O PYY3-36 foi inferior nas mulheres em relação aos homens ao passo que o cortisol foi inferior nos homens comparado com as mulheres. Houve interação entre situação e momento de coleta para o cortisol e insulina sendo os valores mais elevados no EIAI-A que no controle às 2,5 horas de experimento para o cortisol e às 3,25h para insulina. Portanto, embora não tenha havido diferença na energia ingerida relativa entre os tipos de exercícios, àqueles realizados em maior intensidade foram capazes de promover efeitos mais pronunciados na supressão do apetite, independentemente do sexo / Maintaining one\'s health depends, among other things, on controlling body weight, since obesity is associated with the development of chronic diseases. Accordingly, exercise is an effective tool in this control. It has been demonstrated that exercise performed at a high intensity can cause greater reduction in body fat. Among the hypotheses put forward of this phenomenon is the suppression of appetite. However, the understanding of the effect of the intensity on appetite is still incipient. In addition, women may have a greater compensatory response than men. Therefore, the aim of the study was to compare the effect of intensity on absolute and relative (energy intake less caloric expenditure of the exercise) energy intake, hunger and blood concentrations of acylated ghrelin, PYY3-36, insulin, cortisol, glucose, fatty acids, cholesterol and triacylglycerol in men and women. Accordingly, 11 men and 9 women, all eutrophic, underwent six sessions. The first was designed to determine their maximum aerobic power (MAP) on a cycle ergometer, and the second involved performing high-intensity intermittent exercise at maximum intensity (all out) for 60 x 8s: 12s (HIIE-A) in order to determine the total work, which was used for the equalization of the other sessions: a) HIIE-A; b) high intensity intermittent exercise (HIIE) - 60s: 60s at 100% of MAP; c) steady-state exercise (SSE) at 60% of the MAP; d) a control session. Each session lasted a total of 4 hours. The participants arrived in fasting and received a standard breakfast upon arrival. The exercise session was performed 1.5 h after breakfast, and an ad libitum meal was served 4 hours post-breakfast. Blood sample collection and perception of hunger were collected when fasting and at 2, 2.5, 3.25 and 4 hours into the experiment and the area under the curve (AUC) for each of these variables was calculated. A comparison of the blood sample variables and rating of hunger was performed by analyzing the variance of three factors (condition, sex, and time) and the analysis of the variables involving the AUC and energy intake was conducted through examination of two factors (sex and condition) followed by a Bonferroni post-test if significant differences (P<0.05) were observed. There was no difference for the absolute energy intake, however, relative energy intake was higher in the control compared to HIIE-A, HIIE, and SSE, with no differences between the types of exercise and sex. The AUC of hunger was lower in exercises performed at high intensity when compared to the control, regardless of sex. There was interaction between condition and time for cortisol and insulin, with higher levels in the HIIE-A than in the control at 2.5 hours for cortisol and 3.25 hours for insulin. Therefore, although there were no differences in energy intake relative to the types of exercises, those performed at a higher intensity promoted more pronounced effects on appetite suppression, regardless of sex

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-06-02T12:58:47Z No. of bitstreams: 2 Dissertação - Marina Monteiro Celestino - 2016.pdf: 3038939 bytes, checksum: f658681fb77c19cdbec1ee83ee51b443 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-06-02T14:50:30Z (GMT) No. of bitstreams: 2 Dissertação - Marina Monteiro Celestino - 2016.pdf: 3038939 bytes, checksum: f658681fb77c19cdbec1ee83ee51b443 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-06-02T14:50:30Z (GMT). No. of bitstreams: 2 Dissertação - Marina Monteiro Celestino - 2016.pdf: 3038939 bytes, checksum: f658681fb77c19cdbec1ee83ee51b443 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2016-02-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Overweight and obesity are associated with excessive food intake, due to changes in the productions of gastrointestinal hormones productions. Objectives: To evaluated the effect of a herbal extract derived from native species of South America on food intake, acylated ghrelin concentrations and peptide similar to glucagon 1. Material and methods: A randomized, blind, placebo-controlled, crossover design methodology, with intervention in two days with an interval (washout) seven days, consisted of 20 overweight women. Three capsules a mix of herbal medicines were administered, containing 112 mg of yerba mate, guarana 95 mg and 36 mg of damiana, or three placebo capsules containing 100 mg of lactose. The herbal extract was administered 15 minutes before a standardized breakfast (494.50 kcal, carbohydrates 52.67%, 12.91% protein and 34.5% lipid) and a standard lunch (632.05 kcal, 61, 67% carbohydrates, 16.97% protein and 21.44% lipid) for all patients. Food not eaten by the participants was weighed to evaluated food intake. Blood samples were collected at baseline and on days 45, 60, 90, 150, 210 minutes after breakfast in the morning and lunch for determination of plasma glucose concentrations, acylated ghrelin and peptide similar to glucagon 1. To compare the differences of the mean energy food intake and macronutrient was performed paired t-test, for the behavior of hormones was performed ANOVA and was calculated area under the curve and to determine the differences between the areas was performed Student's t test. Results: In the supplemented group, there was significant reduction in energy intake at lunch and macronutrients in both meals (p <0.05). The acylated ghrelin concentrations were lower after breakfast (p <0.05) and glucagon-like peptide 1 were higher (p <0.05) after breakfast in the supplemented group. Conclusion: Supplementation with herbal mix reduced energy intake and macronutrients by the modulating hormones glucagon-like 1 and acylated ghrelin in overweight and obesity women. / O excesso de peso se relaciona com a ingestão alimentar excessiva, decorrente de alterações nas produções de hormônios gastrointestinais. Objetivos: Avaliar o efeito de um extrato de ervas oriundos de espécies nativas da América do Sul sobre a ingestão alimentar, as concentrações de grelina acilada e peptídeo semelhante ao glucagon 1. Material e métodos: Ensaio clínico randomizado cego, crossover com intervenção em dois dias, com intervalo (washout) de sete dias, composto por 20 mulheres adultas com excesso de peso. Foram administradas três cápsulas de um extrato de ervas, contendo 112 mg de erva-mate, 95 mg de guaraná e 36 mg de damiana, ou três cápsulas de placebo, contendo 100 mg de lactose. O extrato de ervas foi administrado 15 minutos antes de um desjejum padronizado (494,50 kcal, 52,67% carboidratos, 12,91% proteínas e 34,5% lipídios) e de um almoço padronizado (632,05 kcal, 61,67% carboidratos, 16,97% proteínas e 21,44% lipídios) para todas pacientes. Os alimentos não ingeridos pelos participantes foram pesados para avaliar a ingestão alimentar. Foram coletadas amostras de sangue no início do estudo e nos tempos de 45, 60, 90, 150, 210 minutos após o café-da-manhã e almoço para determinação das concentrações plasmáticas de glicose, grelina acilada e peptídeo semelhante ao glucagon 1. Para comparar as diferenças das médias da ingestão alimentar energética e de macronutrientes foi realizado o teste t pareado, para o comportamento dos hormônios foi realizado ANOVA e foi calculado a área abaixo da curva e para determinar as diferenças entre as áreas foi realizado teste T de Student. Resultados: No grupo suplementado, foi observada redução significativa da ingestão energética no almoço e de macronutrientes em ambas as refeições (p < 0,05). As concentrações de grelina acilada foram menores após o almoço (p <0,05) e de peptídeo semelhante ao glucagon 1 foram maiores (p < 0,05) após o desjejum no grupo suplementado. Conclusão: A administração do extrato de ervas reduziu a ingestão calórica e de macronutrientes sugerindo que possa ter ocorrido por meio da modulação da ação dos hormônios peptídeo semelhante ao glucagon 1 e grelina acilada em mulheres com sobrepeso e obesidade.