Les études à long-terme confirment que la combinaison d’un déficit calorique et d’un programme d’exercice est une intervention plus profitable quant à la perte de poids qu’un régime hypocalorique ou un programme d’exercice seul. Toutefois, la perte de poids moyenne de l’approche combinée est en générale inférieure à celle estimée sur la base du déficit calorique et de la dépense énergétique du programme d’exercice. L’objectif principal de cette étude portait sur l’investigation des effets d’un déficit calorique et de l’exercice sur l’apport calorique, la dépense énergétique totale, la thermogenèse d’origine autre que l’exercice et la compensation alimentaire post-exercice chez les jeunes femmes. Huit jeunes femmes de poids normal et inactives ont participé à quatre conditions expérimentales : contrôle; exercice, où une séance d’exercice à intensité modérée a été réalisée; déficit calorique, où un déficit calorique de 25% pour une période de 3 jours consécutifs a été respecté; et exercice/déficit calorique. À la suite de chaque session, un repas ad libitum à l’heure du dîner a été offert aux participantes et des boîtes à lunch contenant des aliments à volonté choisis par l’entremise de menu ont été remises à ces dernières pour couvrir l’apport calorique pour la journée (jour 1) ainsi que la journée subséquente (jour 2). De plus, un accéléromètre a été remis à chaque participante après chaque séance expérimentale pour être en mesure d’estimer la dépense énergétique liée à l’activité physique pour le jour 1 et jour 2. Aucune différence significative n’a été observée entre les différentes conditions expérimentales pour l’apport calorique au repas ad libitum post-exercice, au jour 1 ainsi qu’au jour 2. De plus, aucune différence significative n’a été notée pour la dépense énergétique totale ainsi que la thermogenèse d’origine autre que l’exercice et aucune compensation alimentaire post-exercice n’a été observée en fonction des conditions expérimentales. Ces résultats suggèrent que la combinaison d’un déficit calorique de 3 journées consécutives avant une séance d’exercice d’intensité modérée n’influence pas l’apport calorique post-exercice, la dépense énergétique totale, la thermogenèse d’origine autre que l’exercice et n’engendre pas de compensation alimentaire post-exercice. Un déficit calorique combiné à l’exercice d’une période plus prolongée pourrait être nécessaire afin d’observer une augmentation de la compensation alimentaire post-exercice pendant une intervention qui vise à induire une perte de poids.

Emerging evidence suggests that sedentary behaviour is independently associated with cardiometabolic disease risk in school-aged children and youth. This thesis includes 4 related studies in the pursuit of 2 objectives: 1) To determine the cross-sectional association of sedentary time, interruptions in sedentary time, sedentary bout length, and total movement variability with markers of cardiometabolic disease risk among children and youth, and 2) To examine the impact of 1-day of prolonged sedentary behaviour, with and without interruptions or structured physical activity, on markers of cardiometabolic disease risk, hunger, food intake and spontaneous physical activity levels in children and youth. In Study 1, we found that interruptions in sedentary time and short bouts of sedentary time were beneficially associated with clustered cardiometabolic disease risk in boys and girls aged 8-11 years, independent of total sedentary time, moderate-and-vigorous physical activity (MVPA), and other confounders (all p<0.05), while the opposite was true for screen based sedentary behaviours. In Study 2, we found that movement variability (minute-to-minute changes in movement intensity) was negatively associated with clustered cardiometabolic disease risk and systolic blood pressure independent of MVPA, sedentary time and other covariates in a representative sample of American children and youth aged 12-17 years (all p<0.05). In Studies 3 and 4, we found that prolonged sitting, with or without interruptions and structured MVPA did not result in acute changes in markers of cardiometabolic disease risk, nor subsequent ad libitum food intake or physical activity levels in healthy children aged 10-14 years (all p ≥0.05). Taken together, the studies that make up this thesis suggest that optimal levels of cardiometabolic disease risk are most likely to be seen in children who limit their time engaging in screen-based sedentary behaviours, who frequently interrupt their sedentary time, and who have high levels of variability in their movement behaviours.

This thesis aims to determine energy compensation following exercise induced energy expenditure (ExEE). The specific objectives were: I) to determine the impact of the time spent performing physical activity (PA) of varying intensities on body weight and composition (Study 1); II) to determine the overall energy compensation and the major predictors of energy compensation through the systematic review approach (Study 2); III) to develop new methods to measure energy intake (EI) (Study 3) and time spent performing different activities (Study 4); IV) to determine the effects of a lower (LI) and higher intensity (HI) ExEE intervention on energy compensation (Study 5); and V) to investigate the inter-individual variability regarding exercise induced energy compensation (Study 6). In Study 1, women spending more time performing light-intensity PA were shown to have lower adiposity compared to women spending more time performing moderate- and high-intensity PA. Results from Study 2 (systematic review) show an overall energy compensation of 25% following exercise interventions and that fat mass (FM), exercise intensity and duration of the intervention are the main predictors of energy compensation. To better capture energy compensation (i.e., EI and EE), new methods to measure EI and time spent performing activities were developed (Studies 3 and 4) and used in the following studies. In Study 5, overweight/obese women training at HI displayed higher energy compensation when compared to women training at LI, which was accompanied by a reduction of NSPA (non-structured physical activity) and a greater amount of time spent lying down. Results from Study 6 showed that complete compensators (CC) had higher EI, fat and carbohydrate intake at the onset of the ExEE intervention when compared to incomplete compensators (IC). However, the results also showed that dietary disinhibition was increased, whereas NSPA was decreased at the end of the intervention in IC. Taken together, these studies emphasize that weight loss following exercise is impeded by energy compensation. In addition to the impact of FM, exercise intensity and duration of the intervention on energy compensation, NSPA and cognitive factors also seem to modify energy compensation that occurs as a result of exercise.

Watching television or listening to music during exercise has been shown to increase the enjoyment of the activity and decrease fatigue for some people. However, it is currently unknown how these stimuli during an exercise session play a role in postexercise energy intake and/or physical activity energy expenditure (PAEE). The purpose of this thesis was to examine the effects of watching television or listening to music while exercising on post-exercise energy intake and expenditure in male adolescents. The study consisted of a randomized crossover design involving 24 male adolescents aged 12 to 17 years. The participants completed three experimental sessions that included walking/jogging on a treadmill at 60% of their heart rate reserve for 30 minutes while watching television, listening to music, or exercising with no other stimulus (control). Following the exercise sessions participants were given an ad libitum lunch and were asked to record their food intake for the remainder of the day. An Actical accelerometer was used to assess PAEE until bedtime. The primary outcome measure was post-exercise energy intake and energy expenditure. Results showed that exercising while watching television or listening to music did not significantly affect postexercise energy intake or energy expenditure. Walking/jogging on a treadmill was found to be more enjoyable while watching television than with no stimulus present (p=0.03). Ratings of perceived exertion were not significantly different between conditions. Overall, our results suggest that watching television or listening to music while exercising does not impact post-exercise energy intake or expenditure in male adolescents, which may have positive implications for adolescents who may need additional motivation to exercise.

The overarching objective of this study is to assess the effectiveness and performance of ATIs. In doing so, this research provides a fundamental understanding of the flow and sediment propagation through a different combination of porous media (pea gravel and woodchips). The research hypothesizes that the theory of advection and diffusion describes the migration of flow and identifies a myriad of depositional networks of sediment. A key hypothesis of the study is that global and local pressure differentiation affects the flow pathways and distribution with intimate effects of sediment trapping efficiency and distribution within the permeameter. A significant goal of this study is to decompose the key mechanisms that affect this migration of sediment under a fixed value for the head and incoming concentration. The nature of the study is experimental and is supported by limited numerical and field analysis. Although the experimental setup is site specific to the conditions encountered in the study location, it offers a generic way of examining flow and sediment intrusion within a permeable bed. The study in that sense hypothesizes that the intrusion by Einstein is valid and it shows the change in the hydraulic gradient that occurs during an event and during a sequence of events. A secondary goal of this research is to understand the cyclicity in the migration of sediment in a sequence of different events, where the initial conditions of each run constitutes the outcome of the final result of the previous runs. The nature of those experiments is to mimic the occurrence of sequential events in nature, although the continuous examined in the laboratory as reflective of conditions representing extreme runs. This research also treats the hydraulic conductivity as a dynamic entity to reflect the effect of localized clogging on the propagation of flow. The experimental design of this research considers a series of experimental runs to address the aforementioned objectives of this research and test the posed hypothesis.

The ability to economically desalinate seawater in arid regions of the world has become a vital advancement to overcome the problem on freshwater availability, quality, and reliability. In contrast with the major capital and operational costs for desalination plants represented by conventional open ocean intakes, subsurface intakes allow the extraction of high quality feed water at minimum costs and reduced environmental impact. A seabed filter is a subsurface intake that consists of a submerged slow sand filter, with benefits of organic matter removal and pathogens, and low operational cost. A site investigation was carried out through the southern coast of the Red Sea in Saudi Arabia, from King Abdullah University of Science and Technology down to 370 kilometers south of Jeddah. A site adjacent to the Shoaiba desalination plant was selected to assess the viability of constructing a seabed filter. Grain sieve size analysis, porosity and hydraulic conductivity permeameter measurements were performed on the collected sediment samples. Based on these results, it was concluded that the characteristics at the Shoaiba site allow for the construction of a seabed filtration system. A seabed filter design is proposed for the 150,000 m3/d Shoaiba III expansion project, a large-scale Reverse Osmosis desalination plant. A filter design with a filtration rate of 7 m/d through an area of 6,000 m2 is proposed to meet the demand of one of the ten desalination trains operating at the plant. The filter would be located 90 meters offshore where hydraulic conductivity of the sediment is high, and mud percentage is minimal. The thin native marine sediment layer is insufficient to provide enough water filtration, and consequently the proposed solution involves excavating the limestone rock and filling it with different layers of non-native sand and gravel of increasing grain size. An initial assessment of the area around Shoaiba showed similar sedimentological conditions that could lead into the application of comparable seabed filter design concepts to supply the entire feed water requirement of the plant. Considerations for the construction of a seabed filter should include technical feasibility and life cycle assessment, i.e. capital costs, operating costs and environmental impacts.

MPH / Department of Public Health / South African HIV epidemic remains the largest in the world with an estimated 7.7 million people living with HIV in 2018. It accounts for a third of all new HIV infections in southern Africa. In 2018, there were 240,000 new HIV infections and about 71,000 South Africans died from AIDS-related illnesses. To meet the 90 90 90 targets by the end of 2020, patients are subject to uncompromising and long-term commitments of taking at least 95% of their treatment as prescribed. Evidence shows that patients are not adhering to treatment regardless of the systems that the government has initiated. The purpose of this study was to identify factors contributing to non-adherence levels to antiretroviral therapy amongst adults living with HIV and AIDS in Makhado Municipality. A quantitative, descriptive approach was adopted. Data was collected using a questionnaire with closed ended questions. The targeted population was made up of males and females between the ages of 18 to 59. Validity and reliability were ensured in the study. Pretesting was done in Kulani Gateway clinic and 10 respondents were selected. A sample of 225 respondents was selected from the targeted population using convenience sampling. Data analysis was done using statistical package for social sciences (SPSS) version 25.0.The analysed data were presented in tables/percentages and charts. The findings revealed that most respondents(80%) who have been on treatment for less than six months adhere more to treatment than respondents who have been on treatment for more than 24 months (57%). The studies also revealed that about 57.9% of respondents forget to take treatment when they have taken alcohol and 42.1% took their treatment even when they have taken alcohol. Side effects were identified as barriers to adherence. The study indicated most respondents (73.3%) experienced side effects especially in the first few months of commencing treatment. and about 26.7% did not report any side effects. In conclusion, Non-adherence to ART poses a major challenge in most regions of the world and in all stages of HIV infection. When patients adhere to treatment the virus will suppress, quality of life will improve and patients will also prevent cross infections. The study revealed factors contributing to nonadherence to ART that includes alcohol intake and side effects. The study also indicates a strong association between waiting times as a factor to improve on adherence. Therefore the study recommends that an intervention to address alcohol intake and side effects should be carried in Makhado Local Municipality. / NRF

abstract: The assessment and evaluation of dietary intake and nutrition knowledge in female athletes is especially important due to the high prevalence of inadequate intake in this population (Black et al., 2019). This study evaluated 1) the relationship of nutrition knowledge and dietary intake among collegiate female athletes at the National Collegiate Athletic Association (NCAA) Division I, National Junior College Athletic Association (NJCAA), and Club sport levels and 2) the impact of competition level on this relationship as well. Participants (NCAA DI, n=51; NJCAA, n = 36; Club, n = 37) in this study answered two questionnaires, the Nutrition Sport Knowledge Questionnaire (NSKQ) and the Rapid Eating Assessment for Participants (REAP) questionnaire to assess knowledge and dietary intake. Participants also provided anthropometric and demographic information. The NSKQ was scored as a whole and for each of the four subcategories. REAP was scored both by tallying the number of “usually/often” frequency responses and given a numeral score to estimate diet quality. Statistical analysis was conducted using Kruskal-Wallis, Chi-square and Spearman’s correlation tests to compare differences within subgroups of participants and evaluate any relationships that may exist between nutrition knowledge and dietary intake with significance set at p≤0.05. Differences in nutrition knowledge between competition groups were significant, H(2)= 16.94, p< 0.001. NCAA DI (p<0.001) and Club (p<0.001) athletes had higher nutrition knowledge than athletes at the NJCAA level. This was true for overall knowledge as well as knowledge subcategories. However, minimal relationships between nutrition knowledge and dietary intake were found. The overall correlation value was rs(118)= -0.10 (95%CI: -0.28 to 0.08), p>0.05. This suggests those with higher nutrition knowledge did not necessarily have better dietary intake. Improvements in the assessment of nutrition knowledge and quick assessment of dietary quality and the relation between both is needed. / Dissertation/Thesis / Masters Thesis Nutrition 2020

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21603号 / 理博第4510号 / 新制||理||1647(附属図書館) / 京都大学大学院理学研究科生物科学専攻 / (主査)准教授 森 哲, 教授 沼田 英治, 教授 中務 真人 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

The biological process of estrus in cattle is known to initiate behavioral responses as a result of fluctuations in hormones, which may alter time budgeted for feeding. The current study aimed to quantify these variations that may exist in feed intake and behaviors in the days pre and post estrus. For this study, 517 estrous cycles in crossbred beef heifers of divergent sizes were used to analyze the impact of estrus behavior on feeding behavior with or without the presence of a bull. There were few differences in estrus behavior among heifers of divergent sizes, however the presence of a bull influenced all estrus activity parameters. Our findings indicate that feed intake and behaviors were sharply decreased on the day of estrus, but returned to baseline levels the following day. Thus, decreases in feed intake and behavior may serve as an additional tool indicating the onset of estrus.