L’objectif de ce travail était de valider une méthode simple permettant de déterminer la sollicitation des métabolismes aérobie et anaérobie en cours d’activité en prenant l’exemple du tennis. Son principe général est de séquencer l’activité globale composite en sous-activités appelées activités fondamentales AF et de déterminer pour chacune d’entre elles la consigne énergétique DEc(i) afin de modéliser l’adaptation des filières énergétiques grâce au modèle bioénergétique Astrabio©. Des étalonnages permettent d’obtenir les fonctions d’astreinte qui relient DEc(i) à un paramètre mécanique M pertinent, vitesse de déplacement ou cadence de coups, pour les 6 AF sélectionnées au tennis. Une méthode d’analyse vidéo simple utilisant une seule caméra est appliquée lors des matchs de tennis pour déterminer les AF et estimer M. Ces paramètres sont introduits dans le modèle Astrabio© qui détermine la DEc(i) de chaque AF, DE aérobie et DE anaérobie par différence. Les quantités d’énergie aérobie prédites à chaque jeu des matchs ne présentent pas de différence statistique avec celles réellement mesurées par la méthode d’analyse directe de DE (K4b2). Elle met en évidence qu’en dépit d’une DE aérobie moyenne assez faible comprise entre 40% et 60% VO2max, le tennis se caractérise en réalité par des efforts supra-maximaux pouvant atteindre 300% VO2max lors des frappes de balle et le métabolisme anaérobie représente environ 30% de l’énergie totale dépensée sur un match. Cette méthode présente l’intérêt majeur d’être facilement applicable et de décrire l’astreinte réelle d’une activité en fournissant une estimation des DE aérobie et anaérobie à partir de l’analyse vidéo de l’activité / The aim of this study was to present a simple method to access the aerobic and anaerobic components of energy expenditure during activities as tennis. The principle consists in dividing the exercise into several fundamental activities (FA) based on a video recording and to estimate the metabolic power (MP) of each FA, the aerobic energy expenditure (EEO2mod) and the anaerobic energy expenditure thanks to the Astrabio© model. Six FA are selected and each FA is described by a “strain function” connecting MP to the selected pertinent mechanical variable M (speed running V and events frequency ω). The video analysis is used to determine FA, V and ω during tennis match. The parameters V and ω are introduced in the Astrabio© model to calculate MP of each FA. Then, this model calculated the aerobic energy expenditure (EEO2mod) in terms of MP and the anaerobic energy expenditures was calculated by substracting this (EEO2mod). There was no significant difference between calculated and measured oxygen consumptions (p<0.05). This method shows that even when the aerobic EE average is quite low and nearing 50% of VO2max, the total energy expenditure of a point can reach up 2 or 3 times the VO2max of the subjects during points and strokes. In tennis anaerobic metabolism can account for around 30% of the total energy expenditure per game, and almost 70% during points. The interest of this method is to provide a good estimation of aerobic and anaerobic energy expenditures thanks to a simple video analysis. This method presents the advantage that it is easy to apply and requires only simple and inexpensive equipment: a camera, a computer, and a tracking software

Insufficient sleep may be associated with obesity via increased energy intake and/or decreased energy expenditure. The present study therefore aimed to investigate effects of sleep restriction on energy balance in healthy young adults. Participants (14 men, 13 women) aged 35.3 ± 1.0 y with 23.6 ± 0.2 kg/m2 BMI completed a randomized, crossover study exposed to short and habitual sleep with 4 wk washout. Controlled diets were provided during the first 4 d, followed by 2 d of ad libitum eating. Ad libitum energy intake, energy expenditure and physical activity level were determined as well as energy balance and body weight. Results showed that ad libitum energy intake (p = 0.031), as well as total fat (p = 0.018) increased after short compared with habitual sleep, but physical activity level, energy expenditure, energy balance, and body weight remained unaffected by sleep duration. In conclusion, sleep deprivation elevates energy intake, which may lead to positive energy balance over time and increase the risk of weight gain and/or obesity.

Insufficient sleep may be associated with obesity via increased energy intake and/or decreased energy expenditure. The present study therefore aimed to investigate effects of sleep restriction on energy balance in healthy young adults. Participants (14 men, 13 women) aged 35.3 ± 1.0 y with 23.6 ± 0.2 kg/m2 BMI completed a randomized, crossover study exposed to short and habitual sleep with 4 wk washout. Controlled diets were provided during the first 4 d, followed by 2 d of ad libitum eating. Ad libitum energy intake, energy expenditure and physical activity level were determined as well as energy balance and body weight. Results showed that ad libitum energy intake (p = 0.031), as well as total fat (p = 0.018) increased after short compared with habitual sleep, but physical activity level, energy expenditure, energy balance, and body weight remained unaffected by sleep duration. In conclusion, sleep deprivation elevates energy intake, which may lead to positive energy balance over time and increase the risk of weight gain and/or obesity.

Introdução: A síndrome do intestino curto (SIC) representa um estado clínico de má absorção grave, e a gestão dietética de pacientes com SIC é extremamente desafiadora. Uma vez que o grau de desnutrição é frequentemente considerável, a intervenção dietética bem sucedida depende da estimativa mais exata possível das necessidades energéticas para prever as metas da terapia nutricional. Objetivo: Quantificar o gasto energético total (GET) em pacientes com SIC pelo método da água duplamente marcada (ADM). Materiais e Métodos: Neste estudo observacional, o GET foi mensurado pelo método da água duplamente marcada em 22 voluntários, 11 com SIC e 11 controles pareados por sexo, idade e IMC (grupo Controle). O GET foi estimado pela equação de Escott-Stump e a partir de acelerômetro, e foi comparado com o GET determinado pela ADM. O gasto energético em repouso (GER) foi mensurado por calorimetria indireta (CI) e comparado com o GER estimado pela equação de Harris e Benedict. O acelerômetro também foi utilizado para estabelecer o nível de atividade física. Resultados: Os participantes tinham idade (média ± DP) de 53 ± 8 anos. O GET medido por ADM foi significativamente menor no grupo SIC comparado ao grupo Controle (p < 0,01); no entanto, o GET estimado não diferiu significativamente entre os grupos. O GET medido foi significativamente maior do que o GET estimado por fórmula no grupo SIC, (respectivamente 1875 ± 276 e 1517 ± 175 kcal/dia, p < 0,01), assim como para o grupo Controle (2393 ± 445 e 1532 ± 178 kcal/dia, p < 0,01). No entanto, o GET medido foi significativamente menor do que o GET predito a partir do acelerômetro no grupo SIC (2075 ± 298 kcal/dia, p = 0,02), e não diferiu significativamente no grupo Controle (2207 ± 355 kcal/dia, p = 0,21). Não foram verificadas diferenças significantes entre o GER medido e predito para ambos, e entre os grupos. Conclusão: O GET medido em pacientes com SIC foi significativamente maior do que o GET estimado por fórmula, e foi menor quando comparado com os valores dos sujeitos controles. No entanto, o GET estimado a partir do acelerômetro, superestima o GET medido por ADM. As fórmulas atualmente utilizadas na prática clínica parecem subestimar as necessidades de energia de pacientes com SIC. Desta forma, adaptações da estimativa atual, aumentando as prescrições de ingestão energética nestes pacientes parecem ser adequadas para apoiar as necessidades diárias de energia e evitar a subnutrição. / Background: Short bowel syndrome (SBS) is a serious malabsorption disorder, and dietetic management of SBS patients is extremely challenging. Once the degree of undernutrition has been assessed, successful dietary intervention depends on the most accurate estimation and provision of energy needs to provide nutritional therapy goals. Objective: To quantify total energy expenditure (TEE) in SBS patients using the doubly labeled water (DLW) method. Design: In this observational study, TEE was measured by the DLW method in 22 participants, 11 with SBS and 11 gender-age-and BMI-matched controls (Control group). Predicted energy requirements were determined using the Escott-Stump equation and by using and accelerometer, and they were compared with TEE determined with DLW. Resting energy expenditure (REE) was measured using indirect calorimetry and compared with predict REE using the Harris and Benedict equation. The accelerometer was also used to determine physical activity level. Results: Participants were aged (mean ± SD) 53 ± 8 years. Measured TEE was significantly lower in the SBS group compared to the Control group (p < 0.01); however, predicted TEE did not differ significantly between the groups. Measured TEE was significantly higher than predicted TEE for the SBS group, (1875 ± 276 and 1517 ± 175 kcal/d, p < 0.01) and also for the Control group (2393 ± 445 and 1532 ± 178 kcal/d, p < 0.01) when determined by formula. However, measured TEE was significantly lower than predicted TEE (2075 ± 298 kcal/d, p = 0.02) for the SBS group, and did not differ for the Control group (2207 ± 355 kcal/d, p = 0.21) when determined by accelerometer. No significant differences were seen between measured and predicted REE both within and between groups. Conclusion: Measured TEE in SBS patients was significantly higher than predicted using standard equations, but also lower than values for age, BMI and gender-matched non-SBS controls. However, predicted TEE using accelerometer overestimated the measured TEE. Currently-used formulas in clinical practice appear to underestimate energy requirements of SBS patients. Therefore, adjustments to the current estimation, increasing the energy intake requirements in these patients appear to be adequate to support the daily energy requirements and avoid undernutrition.

The female athlete triad (FAT or the TRIAD) is a complex syndrome arising from associations among the trio of energy availability (EA), menstrual function (MF) and bone mineral density (BMD) along their respective continuums from health to disease state. It has been recognized that women whose energy intake (EI) does not meet the energy requirements for physiological functions subsequent to participation in exercise and physical activity could have low EA. In the TRIAD, low EA, an initiator in menstrual dysfunction (MD) and concomitant hypoestrogenism, indirectly results in low BMD. Therefore, the purpose of this study was to: (i) establish the status of EA, MF and BMD among elite Kenyan female athletes and non-athletes, (ii) explore associations between EA and MF in elite Kenyan female athletes and non-athletes, (iii) determine the relationships of EA and MF to BMD in elite Kenyan female athletes and non-athletes, and (iv) to determine the profile of the female athlete triad in elite Kenyan distance athletes and in non-athletes. Measurements of EA, MF and BMD were undertaken in 39 female participants (Middle distance athletes =12, Long distance athletes=13, Non-athletes=14). Energy intake minus exercise energy expenditure (EEE) and the remnant normalized to fat free mass (FFM) determined EA. Energy availability was determined through weight of all food and liquid consumed over three consecutive days. Exercise energy expenditure was determined after isolating and deducting energy expended in exercise or physical activity above lifestyle level from the total energy expenditure output as measured by Actigraph GT3X+. Fat free mass and BMD were assessed using dual energy x-ray absorptiometry (DXA). A nine-month daily temperature-menstrual diary was used to evaluate menstrual status. In addition, since psychological eating behaviour practice (EBP) contributes to low EA, the Eating Disorder Examination Questionnaire (EDE-Q) was used to determine presence of such practice among the participants and their relationship to EA. Overall, EA below 45 kcal.kgFFM-1.d-1 was found in 61.53% of the participants (athletes=28.07±11.45kcal.kgFFM-1.d-1, non-athletes=56.97±21.38kcal.kgFMM-1.d-1). The ANOVA showed that there was a significant difference (p<0.001) in EA among the long and middle distance runners and non-athletes; and the Tukey‘s HSD revealed that the source of the difference were the non-athletes. Results of the EDE-Q showed almost negligible presence of psychopathological eating behaviour practice among the Kenyan participants. None of the TRIAD components showed significant relationship with EBP. Results of MF showed that whereas none of the athletes presented with amenorrhea, oligomenorrhea was present among 40% athletes and 14.3% non-athletes, and amenorrhea among 14.3% non-athletes. However, there was no significant difference between athletes and non-athletes in MF. Low BMD was seen in 76% of the athletes and among 86% of the non-athletes. The analysis did not show significant difference in BMD Z-scores between athletes and non-athletes. The analysis did not show any significant association between EA and MF among the participants. The only significant relation of EA to any BMD dimension measured was between EA and total BMD in the long distance runners (r=0.560; p=.046). Significant relationship (rho=0.497; p=.001) was found between MF and BMD Z-scores among the athletes with middle distance highlighting the relationship further (rho=0.632; p=.027). Overall, the binary logistic regression revealed that MF did not predict BMD (OR=4.07, 95% CI, 0.8-20.7, p=.091). Overall, 10% of the participants (athletes=4, long distance athletes =3, middle distance athletes=1, non-athletes=0) showed simultaneous presence of all three components of the TRIAD. The independent sample t-test showed a significant difference (t=5.860; p=<.001) in the prevalence of the TRIAD between athletes and non-athletes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014

The female athlete triad (FAT or the TRIAD) is a complex syndrome arising from associations among the trio of energy availability (EA), menstrual function (MF) and bone mineral density (BMD) along their respective continuums from health to disease state. It has been recognized that women whose energy intake (EI) does not meet the energy requirements for physiological functions subsequent to participation in exercise and physical activity could have low EA. In the TRIAD, low EA, an initiator in menstrual dysfunction (MD) and concomitant hypoestrogenism, indirectly results in low BMD. Therefore, the purpose of this study was to: (i) establish the status of EA, MF and BMD among elite Kenyan female athletes and non-athletes, (ii) explore associations between EA and MF in elite Kenyan female athletes and non-athletes, (iii) determine the relationships of EA and MF to BMD in elite Kenyan female athletes and non-athletes, and (iv) to determine the profile of the female athlete triad in elite Kenyan distance athletes and in non-athletes. Measurements of EA, MF and BMD were undertaken in 39 female participants (Middle distance athletes =12, Long distance athletes=13, Non-athletes=14). Energy intake minus exercise energy expenditure (EEE) and the remnant normalized to fat free mass (FFM) determined EA. Energy availability was determined through weight of all food and liquid consumed over three consecutive days. Exercise energy expenditure was determined after isolating and deducting energy expended in exercise or physical activity above lifestyle level from the total energy expenditure output as measured by Actigraph GT3X+. Fat free mass and BMD were assessed using dual energy x-ray absorptiometry (DXA). A nine-month daily temperature-menstrual diary was used to evaluate menstrual status. In addition, since psychological eating behaviour practice (EBP) contributes to low EA, the Eating Disorder Examination Questionnaire (EDE-Q) was used to determine presence of such practice among the participants and their relationship to EA. Overall, EA below 45 kcal.kgFFM-1.d-1 was found in 61.53% of the participants (athletes=28.07±11.45kcal.kgFFM-1.d-1, non-athletes=56.97±21.38kcal.kgFMM-1.d-1). The ANOVA showed that there was a significant difference (p<0.001) in EA among the long and middle distance runners and non-athletes; and the Tukey‘s HSD revealed that the source of the difference were the non-athletes. Results of the EDE-Q showed almost negligible presence of psychopathological eating behaviour practice among the Kenyan participants. None of the TRIAD components showed significant relationship with EBP. Results of MF showed that whereas none of the athletes presented with amenorrhea, oligomenorrhea was present among 40% athletes and 14.3% non-athletes, and amenorrhea among 14.3% non-athletes. However, there was no significant difference between athletes and non-athletes in MF. Low BMD was seen in 76% of the athletes and among 86% of the non-athletes. The analysis did not show significant difference in BMD Z-scores between athletes and non-athletes. The analysis did not show any significant association between EA and MF among the participants. The only significant relation of EA to any BMD dimension measured was between EA and total BMD in the long distance runners (r=0.560; p=.046). Significant relationship (rho=0.497; p=.001) was found between MF and BMD Z-scores among the athletes with middle distance highlighting the relationship further (rho=0.632; p=.027). Overall, the binary logistic regression revealed that MF did not predict BMD (OR=4.07, 95% CI, 0.8-20.7, p=.091). Overall, 10% of the participants (athletes=4, long distance athletes =3, middle distance athletes=1, non-athletes=0) showed simultaneous presence of all three components of the TRIAD. The independent sample t-test showed a significant difference (t=5.860; p=<.001) in the prevalence of the TRIAD between athletes and non-athletes. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2014

Background Middle-income countries are currently undergoing nutrition transition more rapidly than did high income countries. These populations are therefore at high risk of over-nutrition (obesity) and nutrition-related, non-communicable diseases before the elimination of under-nutrition and infectious diseases. Such nutritional double burden is most common in low SES groups of middle-income countries, such as the Maya of Mexico. Long-term poor environmental conditions during early life results in a population with high levels of chronic under-nutrition (stunting), and a consequent predisposition toward overweight/ obesity, and associated health risks later in life. It is important to be able to identify individuals at an increased risk of diseases related to double burden and to determine whether stunting impacts the ability to identify at risk individuals. Aims The overall purpose of this doctoral research was to examine double burden in the urban Maya, a low SES section of the Mexican population which is a current example of a population undergoing significant transition. The specific aims of this thesis were fourfold: 1) To describe the living conditions and population characteristics of the urban Maya of southern Merida in the spring and summer of 2010; 2) to determine whether body mass index (BMI) predicts adiposity indicators in a sample of women and children with a high prevalence of stunting, 3) to determine whether measures of linear growth in women can be predicted by their recalled childhood environment and 4) To determine whether the relationship between objectively estimated free-living energy expenditure and body composition is altered by stunting. Methods Data from interviews, anthropometric measurements and bioelectrical impedance analysis were collected on 58 Maya schoolchildren aged 7-9 years-old and their mothers living in the south of Merida, Mexico. Objective, free-living physical activity monitoring using combined accelerometry and heart rate monitoring of the children was also performed for one week. The interview data was used to describe the living conditions of the south of Merida. Whether stunting status or body proportions influenced the power of BMI to predict adiposity indicators was assessed for the mothers and the children. The mothers recalled early life SES was compared to their current measures of linear growth. The children s objectively estimated energy expenditure was compared to their body composition and measurements of body size. Results The Maya of southern Merida overall had access to clean drinking water and basic health care and have apparently eliminated acute under-nutrition. Yet they remained double burdened with simultaneous stunting and overweight/ obesity. Individual double burden levels were high, with 70% of the mothers were simultaneously stunted and overweight. Family level double burden was also high, with 28% of the families having an overweight mother and a stunted child. The rates of childhood malnutrition varied widely when using different cut-offs. Child stunting rates were between 15.5% and 37.9% when using -2 z-scores of Frisancho s Comprehensive (created using NHANES data) reference versus the 5th percentile of the WHO reference, respectively. Child overweight/ obesity rates were less than 10% when using weight-for-age on both the Comprehensive and WHO reference charts. Child overweight/ obesity as classified using BMI z-scores was between 27.5 to 34.5% using the Comprehensive and WHO reference, respectively, while child overfat was over 80% when using body fat percentage for age reference curves. BMI predicted adiposity indicators in these Maya children, explaining between 33 and 84% of the variance in arm fat index and waist circumference z-score, respectively. BMI was less strongly related to the mothers adiposity indicators, explaining between 19 and 70% of the variance in arm fat area and waist circumference. The relationship between BMI and adiposity indicators was unchanged by stunting or body proportions in either mothers or children. Mothers recalled early life SES was significantly related to but explained little of the variance in her measures of linear growth. Birth decade explained 5% of the variance in stature and the Modernisation index (urban/ rural birth, sugar sweetened beverage consumption, packaged food consumption) explained 5% of the variance in mothers leg length. Birth order, sibling number and consumer durable ownership were also significantly related to linear growth of the mothers. These Maya children had high levels of physical activity, as all exceeded the recommended 60 minutes of moderate-to-vigorous physical activity per day. After controlling for fat free mass, short stature did not predict lower resting energy expenditures in the children. However shorter stature did predict lower levels of activity energy expenditure, particularly in girls. Stunted girls had the lowest activity energy expenditures. Conclusions These urban Maya tend to have access to basic sanitation and services and are at a very high risk for NR-NCDs with the co-existence of chronic under-nutrition (stunting) and overweight/ obesity. The high rates of stunting do not impact the usefulness of BMI to estimate adiposity nor does stunting appear to impact children s energy expenditure. While BMI is useful to predict adiposity in these urban Maya children, it is not recommended for use in the mothers. Interventions to reduce childhood adiposity need to begin very early in life to most effectively reduce adiposity. Research into the low SES groups of middle-income countries, offers insight to what may occur in low-income countries as they advance in the nutrition transition.

L’obésité et la sédentarité sont considérées comme des problèmes importants de santé publique. L’augmentation de l’activité physique est une des stratégies recommandées pour obtenir un bilan énergétique positif dans les interventions de perte de poids. Deux accéléromètres, le Sensewear Armband (SWA) et l’Actical (ACT), sont des outils simples à utiliser en recherche clinique, mais à notre connaissance, aucune étude n’a évalué leur capacité à détecter des hausses de la dépense énergétique. De plus, très peu d’études, avec des résultats par ailleurs contradictoires, ont été effectuées afin de déterminer la fiabilité de ces accéléromètres pour la mesure de la dépense énergétique au repos et au cours d’une activité physique au vélo stationnaire. Ainsi, les objectifs de cette étude étaient: 1) évaluer, pendant 3 journées consécutives, la reproductibilité des valeurs de la dépense énergétique obtenues avec le SWA et l’ACT, au repos et au cours d’une activité physique de 45 minutes sur un vélo stationnaire, 2) déterminer la capacité de ces accéléromètres à détecter des hausses de 5% et 10 % de la dépense énergétique totale (DET) au moyen de la modification d’une activité physique au tapis roulant pendant 45 minutes. Cette étude transversale effectuée auprès de 20 sujets en santé, âgés de 20 à 32 ans et avec un IMC moyen de 23 kg/m2, consistait en 5 visites à la clinique. Les 3 dernières visites, sous supervision directe pendant 10 heures, comportaient des activités programmées sur le vélo stationnaire et la marche sur tapis roulant pendant 45 minutes. Les résultats montrent que le SWA et l’ACT donnent des valeurs reproductibles pour estimer la dépense énergétique au repos et la dépense énergétique au vélo (corrélations intra classe, p<0,001). Par contre, pour des hausses préétablies de la DET de 5% et 10%, les estimations respectives obtenues étaient de 1,4% et 7,8% avec le SWA et de 3,4% et 13,1% avec l’ACT. Le SWA sous-estime les hausses de 5% et de 10% et l’ACT sous-estime la hausse de 5% et surestime la hausse de 10% de la DET. Plus de recherches sont nécessaires avant de confirmer l’usage du SWA et de l’ACT dans l’estimation des hausses de la dépense énergétique totale. / Obesity and physical inactivity are considered significant public health problems. Increasing physical activity is one strategy recommended to induce a positive energy balance in weight loss interventions. Two accelerometers, the Sensewear Armband (SWA) and Actical (ACT), are simple tools to use in research, but to our knowledge, no studies have assessed their capacity to detect increases in energy expenditure. Moreover, very few studies, and with conflicting results, have been conducted to determine the reliability of these accelerometers for the measurement of resting energy expenditure and physical activity energy expenditure on a stationary bicycle. Thus the objectives of this study were as follows : 1) evaluate, during 3 consecutive days, the reproducibility of values of energy expenditure obtained with the SWA and the ACT, at rest and during physical activity for 45 minutes on a stationary bicycle, 2) determine the capacity of these accelerometers to detect increases of 5% and 10% in total energy expenditure (TEE) obtained by modifying an activity on a treadmill for 45 minutes. This cross-sectional study conducted with 20 healthy subjects, aged 20-32 years with an average BMI of 23 kg/m2, consisted of 5 visits to the clinic. The last 3 visits, under direct supervision for 10 hours, included programmed physical activities on a stationary bicycle and on a treadmill for 45 minutes. The results show that the SWA and the ACT provide values which are reproducible for estimating resting energy expenditure and physical activity energy expenditure on the stationary bicycle (intra-class correlations, p<0,001). However, for pre-established increases in TEE of 5% and 10%, corresponding estimations obtained were 1.4% and 7.8% with the SWA and 3.4% and 13.1% with the ACT. The SWA underestimates increases of 5% and 10% and the ACT underestimates increases of 5% and overestimates increases of 10% of TEE. More research is needed before confirming the use of the SWA and the ACT in the estimation of increases in total energy expenditure.

The large capacity of brown adipose tissue (BAT) to expend energy as heat makes it an interesting potential player in weight regulation and other metabolic conditions. This is of particular interest as it has been recognized that adult humans possess BAT. The protein responsible for the heat production is uncoupling protein 1 (UCP1), which, as the name implies, uncouples the respiratory chain from ATP production; instead heat is produced. Cold is the strongest recruiter and activator of BAT. However, also obesogenic food has a low but nonetheless significant effect on the recruitment and activation of UCP1, although the significance of this has been discussed. In the present thesis, I have studied the effect of diet on BAT and the possibilities for it to be obesity-protective. This can be done by comparing responses in wild-type mice and in UCP1-ablated mice. Since the effect of diet on BAT is low, it is of importance to control the temperature and maintain thermoneutrality. Other confounding factors to keep in mind are differences in actual energy and composition of food and also cohort differences. When controlling all the parameters mentioned and giving the mice the same obesogenic diet, the mice possessing UCP1 compared to UCP1-ablated mice had higher energy expenditure, and lower weight gain, despite eating more. This confirms the presence of a UCP1-dependent diet-induced thermogenesis. Thus, the conclusion must be that possessing UCP1 does result in obesity protection at thermoneutrality. However, the relevance for human energy balance is still not established. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 3: Manuscript.</p>

Title: Nutrition monitoring in top Czech Republic women white water slalom athletes in the race period of the season. Aim of the study: Comparison of actual quantitative and qualitative composition of the diet in the Czech water slalom paddlers (women) in the racing period to daily recommended standards for the population group of athletes with a corresponding energy output. Using the results, create both general and individual recommendations and assess the need for the use of supplements in the diet of water slalom athletes. Methods: The thesis is a case study and it is a kind of qualitative research. For our study we chose two main methods. Prospective study method and the method of interview. To determine the total daily energy intake and diet quality inventorial analysis of the four- day dietary record of the respondents was used. For comparison with the standards, the data were subsequently processed by standardized software applications of database functions MS Excel (Vilikus a kol., 2002) and accompanied by a critical commentary. To survey the data concerning use of food supplements has been used a method in which athletes respond to questions asked. The data were assessed in writing and graphically. Results: Our study shows and critically comment on the differences between recommended and...