Saudi Cultural Missions Theses & Dissertations
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Item Restricted Activating the Transportation Potential of Greenways in Saudi Arabia: A Case Study of Jeddah City(University of Nottingham, 2024-04-08) Zawawi, Abdulrahman A.; Porter, Nicole; Ives, Chrisopher D.; Beccarelli, PaoloSince the early 1970s, auto-centric planning in Saudi Arabia (SA) has led to car-dependent lifestyles, resulting in health and environmental problems. In the past decade, ambitious policies (e.g., The Saudi Vision 2030), urban design manuals, awareness campaigns, city plans and projects have sought to address this problem by transitioning to sustainable urban mobility. Active transportation (AT) via networks of greenways is a dimension of such a transition and is currently being planned and advocated in Saudi cities. However, current walking and bicycling rates for transportation in SA are extremely low. Simultaneously, there is limited research on greenways in SA, and none has explored the influences on their usage as AT corridors (ATCs). An enhanced understanding of such factors is vital because academic journals found minimal effect on AT over the last thirty years from many greenway investments in various regions worldwide. Therefore, this PhD research aimed to explore the activation barriers and strategies of greenways’ function as facilitators for AT in SA, using Jeddah city as a case study. The review and synthesis of existing literature built an understanding of the state of knowledge concerning the planning and usage of AT and greenways in SA. It also explained the events that evolved greenways’ forms and functions internationally while chronologically relating to urban and open space planning in Saudi cities. Lastly, it examined where and when greenways would be considered routes for daily commutes using a systematic review of published peer-reviewed journal articles from 1991 until 2021. Due to the multidimensionality of such influences, the case study of Jeddah used mixed research methods (web-based questionnaire, environmental audits, field observations, and interviews with experts and leaders of local walking and bicycling groups). Interpretations and inferences of such an empirical study combined the results of these methods thematically and linked them to existing literature. Through (I) assessments of the physical environment at the city, neighbourhood, and site levels, (II) examining the preferences, behaviours, and opinions of users and non-users of greenways in Jeddah city, and (III) understanding the underlying causes to existing conditions, this thesis underscored key impediments that must be overcome. These include automobile-centric lifestyles, planning systems, outdoor temperature, social norms, long commuting distances, lack of AT infrastructure, bicycling skills and knowledge, proximity to greenways, and park facilities and amenities. Results also explained that religious and gender norms on women’s participation in bicycling can affect social support for policies advocating bicycle usage in Saudi cities and the effectiveness of any proposed greenway network in the future. Informed by the interviewed experts, existing literature, and global best practices, the proposed strategies to address the identified barriers stressed the importance of actions across social, environmental, technological, economic and legal domains. These strategies (e.g., improving stakeholders’ participation, integrating with public transit, increasing visibility and awareness, and implementing policies that enable AT) can accelerate the transition towards sustainable transportation in SA.24 0Item Restricted The Association between Healthy Lifestyle Behaviors and Polypharmacy in Older Adults: The Loma Linda Longevity Study(Loma Linda University, 2024) Bardesi, Abrar; Dos Santos, HildemarIntroduction: Polypharmacy—defined as taking numerous medications that may not be clinically necessary—is becoming a significant concern among the older adult population. This study examined the associations between lifestyle behaviors and the number of prescribed medications in older adults (75 years and older) living in the counties of San Bernardino and Riverside. Methods: This study employed a cross-sectional survey to assess lifestyle behaviors and medication use in 611 older adults aged 75 or over. Bivariate correlation and linear regression analyses were used to assess potential relationships between lifestyle behaviors and the number of prescribed medications. Results: Fruit consumption (p=0.005), mild physical activity per week (p<.001), and lifestyle index (p=0.003) had a highly significant inverse association with the number of prescribed medications. Fat consumption had a direct positive relationship with the number of prescribed medications (p=0.02). Conclusion: Higher fat intake was directly linked to an increased need for medications, while regular physical activity, a higher fruit intake, and a healthy overall lifestyle were all associated with a lower likelihood of polypharmacy. Future research can explore the mechanisms linking these behaviors with medication usage.37 0Item Restricted Assessing appetite responses to physical activity using functional magnetic resonance imaging(Loughborough University, 2024-03-13) Dera, Abdulrahman; Stensel, David; King, James; Thackray, AliceThe relationship between physical activity, sedentary time, and appetite control has potential implications for weight management. Limited evidence suggests that regular physical activity may influence responsiveness to visual food cues in reward-related brain regions. In the past few years, studies have increasingly focused on neural regulation of appetite and feeding. Despite this, there is scarce research examining how physical activity is associated with brain responses to food cues and the circulating peptides that are implicated in the regulation of appetite within the brain. The first study in this thesis (Chapter 4) is a systematic review of functional magnetic resonance imaging (fMRI) studies examining the effect of physical activity on neural responses to visual food cues in humans. Exercise, both acute and chronic, appears to lower food-cue reactivity in several brain regions, including the insula, hippocampus, orbitofrontal cortex (OFC), postcentral gyrus, and putamen, especially when participants view images of high-energy-density foods. Research suggests that acute exercise may enhance the appeal of low-energy-density food choices. Several cross-sectional studies have demonstrated that individuals with high levels of self-reported physical activity show less reactivity to food cues, particularly cues depicting high-energy-density foods, in the insula, OFC, postcentral gyrus, and precuneus. The results of this review suggest that physical activity may affect food-cue reactivity in motivational, emotional, and reward-related brain regions, possibly indicating a hedonic appetite suppression effect. However, considering methodological variability across a limited number of studies, conclusions should be drawn with caution. The second study reported in this thesis (Chapter 5) used a randomised crossover design to investigate the acute effect of vigorous-intensity exercise (treadmill running) on cerebral blood flow (CBF). This study explored the time course of CBF changes after acute exercise in healthy men using fMRI and its implications for food-cue reactivity paradigms. Overall, differences between trials were evident in grey matter and regional CBF, but the CBF time course was not influenced by exercise, suggesting that food-related blood-oxygen-level-dependent (BOLD) acquisitions after exercise may not be time-sensitive. In future studies, it may be necessary to acquire BOLD and CBF data simultaneously so that differences in CBF between trials that may affect the interpretation of brain food cue reactivity can be considered. ii The third study reported in this thesis (Chapter 6) is a cross-sectional study examining the association of physical activity and sedentary behaviour with neural responses to visual food cues in adults. A negative relationship was found between moderate to vigorous physical activity (MVPA) and food-cue reactivity in the hippocampus, insula, amygdala, middle frontal gyrus, and precentral gyrus. A positive association was identified between MVPA and food-cue reactivity in the striatum, whereas sedentary time was positively associated with food reactivity in the posterior cingulate gyrus and paracingulate gyrus, independently of BMI. Moreover, fasting glucagon-like peptide-1 (GLP-1) concentrations correlated negatively with brain reactivity in areas associated with cognition, emotion, and reward. This suggests that low GLP-1 concentrations may increase hunger and motivation to seek food. Fasting glucose concentrations were negatively associated with brain reactivity in response to food cues in the postcentral gyrus, potentially indicating heightened sensitivity to food cues when glucose concentrations are low. Fasting peptide tyrosine-tyrosine (PYY), a hormone associated with feeling full, was negatively associated with food cue reactivity in the middle frontal gyrus. No relationship was observed between fasting acylated ghrelin concentrations, overall appetite perceptions, and brain responses to food cues. This thesis highlights that physical activity and sedentary behaviour influence brain responses to visual food cues. The three studies emphasise the importance of continued research examining links between physical activity and appetite control. The findings provide a broad understanding of how physical activity and exercise (acute and chronic) affect food-cue and appetite perception, including both the neural and hormonal components involved in appetite perception. Understanding of appetite regulation in the brain has been further enhanced by considering CBF, neural pathways, and appetite related hormones. Using this foundation, further research can be conducted exploring ways to improve lifestyles and eating habits.25 0Item Restricted Exercise and quality of life in patients with alpha-1 antitrypsin deficiency(Saudi Digital Library, 2023-12-04) Alshahrani, Mohammed; Pye, Anita; Turner, AliceIntroduction Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder that affects the production of a protein called alpha-1 antitrypsin. This protein helps to protect the lungs from damage. People with AATD are at increased risk of developing lung and liver diseases. This dissertation explores the effectiveness of exercise on the quality of life in AATD patients. Physical activity is known to have many health benefits, including improving lung function, and reducing the risk of chronic diseases. However, it is not clear whether physical activity is beneficial for people with AATD. The main aim of this study is to examine the relationship between exercise and quality of life in AATD patients who lead physically active or sedentary lifestyles. Methods This cross-sectional study examined the associations between physical activity, quality of life, and well-being in 64 participants with AATD. Utilising a customised questionnaire, activity levels and perspectives were evaluated. More clinical information was extracted from the AATD registry. Results There were 64 participants whose ages and lung function varied considerably. Perspectives on physical activity varied; some were physically active while others were sedentary. The impact of AATD on activity capacity varied among participants. The majority of respondents reported that physical activity improves Quality of life (QOL) and emotional health, but some described barriers. Diverse forms of exercise were preferable. Patients who engaged in more physical activity reported improved quality of life, including less shortness of breath, fatigue, and anxiety, according to the results. In addition, they reported having higher levels of energy and generally feeling better. Positive correlations were observed between physical activity, QOL, and emotional well-being. Conclusion These findings suggest that physical activity would be a beneficial intervention for AATD patients. in addition, this dissertation highlights the importance of incorporating exercise as an integral component of holistic health management for individuals with AATD, showcasing its potential to improve various dimensions of quality of life, both physically and emotionally. However, more research is needed to confirm these findings and to determine the optimal amount and type of physical activity for AATD patients with larger sample size.14 0Item Restricted A Narrative Review: Reducing Obesity among Adolescent Girls through Physical Activity(Saudi Digital Library, 2023-11-03) Altuwayrib, Khawlah Abdullah; Carlton, JillBackground The prevalence of obesity among adolescent girls is increasing at an alarming rate, raising major health and social concerns. Physical activity is an important factor in the fight against obesity, but its effectiveness is sometimes still ambiguous. Aim The aim of this narrative review is to bring together and critically evaluate the available research on the role of physical activity in reducing obesity rates among adolescent girls. This review focuses on investigating the effectiveness of different types of interventions and highlights the methodological rigor of the included research. Design A narrative review design was used for the purpose of providing a comprehensive overview and critical appraisal of available research in the field. Search Strategy A search was performed using reputed databases such as PubMed and Cochrane. Keywords such as “adolescent girls,” “obesity,” “physical activity,” and “body weight” were used to extrapolate scientific references. Studies published from 2013 to 2023 were analysed. Review Method Twelve studies were selected based on several criteria, including relevance to the research question, methodological rigor, and scientific contribution to the field of study. These studies were carefully evaluated by analysing the strengths and weaknesses of each study, as well as estimating the implications. Results The review found that there is positive appreciation for the effectiveness of high-intensity interval training (HIIT), educational interventions and school-based programs in reducing obesity rates among adolescent girls. However, studies have also shown that there are factors that need to be considered when designing these interventions, such as unhealthy behaviours including increased screen time. Among noted limitations were small sample sizes in some studies, lack of control groups in some cases, and reliance on self-reported data without independent verification. Conclusion The findings affirm the role of physical activity in managing obesity among adolescent girls but also highlight the complexity of the issue. Future research should focus on long-term interventions, multidisciplinary approaches, and gender-specific factors. The review serves as a critical guide for clinicians, educators, policymakers, and researchers aiming to develop more effective, evidence-based strategies for obesity management in adolescent girls.13 0Item Restricted The Association Between Lifestyle Behaviour, including Physical Activity and Dietary Habits, and their relationship with Hypertension in a UK Population Sample(Saudi Digital Library, 2023-08-14) Fakeeh, Mohammed; Nicholl, BarbaraBackground: high blood pressure is a crucial contributor to the development of cardiovascular disease and a significant public health concern that affects millions of people globally. There has been growing discussion about hypertension among adults and the role that lifestyle factors play in this condition. There is a high level of physical inactivity and poor dietary choices in the United Kingdom (UK), both of which might contribute to hypertension. Objective: This study aimed to investigate the association between lifestyle factors – including physical activity and dietary habits – and sociodemographic factors and their associations with high blood pressure using a UK Biobank sample. Methods: Participants from the UK Biobank were included (N = 230,087) who had self- reported hypertension. The chi-squared test was utilised for categorical variables and the Mann–Whitney U test was utilised for continuous variables to compare dietary, sociodemographic and physical activity-related variables between groups with and without hypertension. Multivariable logistic regression analysis was used to establish whether there was an association between hypertension (the dependent variable) and physical activity and dietary habits, including the consumption of tea, coffee, beef, salt added to food, raw salad and vegetables (the independent variables). We then adjusted for a wide range of potential covariates (age, sex, Townsend scale score, body mass index (BMI), smoking status and alcohol consumption). The analysis was carried out using R software (v. 4.2.1). Results: The findings indicate an association between hypertension and physically active individuals compared to those reporting low physical activity levels (odds ratio (OR): 1.13, 95% confidence interval (CI) (1.10–1.16), p < 0.001). In contrast, dietary habits varied. Tea and beef consumption were found to have significant associations with hypertension ((OR tea – light to moderate: 1.05, 95% CI (1.02–1.09), p = 0.002); OR beef – once a week: 1.10, 95% CI (1.06– 1.14), p < 0.001), while consumption of coffee and salt added to food had negative associations with hypertension ((OR coffee – light to moderate: 0.90, 95% CI (0.88–0.93), p < 0.001); OR salt –usually: 0.82, 95% CI (0.80–0.84), p < 0.001). The analysis of sociodemographic factors revealed that older people and males were likelier to experience hypertension than younger people and females, respectively ((OR age – 60–71 years: 4.09, 95% CI (3.96–4.22) p < 0.001); (OR sex – male: 1.34, 95% CI (1.32–1.37), p < 0.001). On the Townsend scale, those in quintiles Q3–Q5 had greater exposure to hypertension than those in quintile Q1-Q2 (OR: 1.09, 95% CI (1.04–1.14), p = 0.001). Overweight and obese people and smokers were significantly likelier to experience hypertension than those with a healthy weight ((OR BMI – overweight: 1.91, 95% CI (1.86–1.97), p < 0.001); OR BMI – obese: 4.14, 95% CI (4.02–4.26), p < 0.001) and those who never smoked (OR smoking – previous: 1.11, 95% CI (1.09–1.14), p < 0.001). Finally, the consumption of raw salad, vegetables and alcohol demonstrated no significant associations with hypertension. Conclusion: This study highlights the associations between lifestyle behaviours, including physical activity and dietary habits, and their relationships with hypertension in a sample from the UK Biobank. Evidently, lifestyle behaviours are crucial to hypertension. However, some associations emerged in unexpected directions, suggesting that further research in this area should be conducted using longitudinal data.15 0Item Restricted Effects of Physical Activity, Exercise and Breakfast Timing Manipulations on Glucose Metabolism in Healthy Adolescents(Saudi Digital Library, 2025-10-27) Afeef, Sahar; Tolfrey, Keith; Barrett, Laura A; Zakrzewski-Fruer, Julia KPostprandial hyperglycaemia is associated with an increased risk of type 2 diabetes (T2D) and cardiovascular disease (CVD). Even in healthy individuals, hyperglycaemia can adversely impact cardiometabolic health. Multiple rises and falls in glucose concentrations (i.e., glycaemic variability) may harm vascular health. Since most of the day is often spent in a postprandial state, measuring glucose concentrations over this critical period is vital to assess glycaemic profile. The novelty of continuous glucose monitoring (CGM) systems enables the assessment of glycaemic variability and postprandial glycaemia with reduced invasiveness and under free-living conditions. Since cardiometabolic risk factors were found to begin early in life, interventions focusing on moderating postprandial glycaemia and glycaemic variability through physical activity (PA) and diet manipulations should start early in life. Therefore, this thesis aimed to investigate postprandial glycaemic responses and glycaemic variability in relation to PA, exercise and breakfast timing manipulations in healthy adolescents aged 11 to 14 years. The first experimental study, Chapter 4, compared interstitial fluid glucose concentration ([ISFG]) obtained by CGM (i.e., FreeStyle Libre) against capillary plasma glucose concentration ([CPG], reference method) in response to an oral glucose tolerance test (OGTT, 5 time points including fasting) and treadmill exercise at different intensities (5 time points) in 17 healthy adolescents (9 girls, mean ± SD age 12.8 ± 0.9 y, BMI 18.4 ± 2.1 kg∙m−2). The overall mean absolute relative difference was 13.1 ± 8.5%. The [ISFG] was significantly lower than [CPG] 15 (−1.16 mmol·L−1, −9.7%) and 30 min (−0.74 mmol·L−1, −4.6%) after OGTT. Yet, post-OGTT glycaemic responses assessed by total (tAUC) and incremental (iAUC) area under the curves were not significantly different with trivial to small effect sizes (P ≥ 0.084, d = 0.14 – 0.45). These results indicate that CGM is an acceptable device reflecting postprandial glycaemic responses (i.e., AUC) that have high relevance to CVD risk. Non-significant site by timepoint interactions were observed during the treadmill exercise tests (P ≥ 0.614), indicating that the pattern of [ISFG] assessed by CGM was similar to [CPG] across the time points. Consequently, CGM were used in the two subsequent studies (Chapters 5 & 6). Using objective monitoring devices (i.e., Actigraph and CGM), Chapter 5 examined the associations of daily glycaemic variability with sedentary time and PA levels measured under free-living conditions in 37 healthy adolescents (24 girls, 12.7 ± 1.0 y, 20.1 ± 3.7 kg∙m−2). Glycaemic variability measures were not significantly associated with time spent sedentary and PA levels after accounting for age, sex, maturity status, accelerometer wear time and % body fat (P ≥ 0.071). However, there are some potential associations between glycaemic variability measures and sedentary time and MVPA. The findings suggest that accumulating 60 min MVPA daily tended to associate with 0.04 mmol∙L−1 reduction in StDevG (β = –0.00068, P = 0.087) and 0.7% reduction in glucose CV (β = –0.012038, P = 0.086). The magnitude of changes is small, and the metabolic health implications of such reductions are not known. Furthermore, the results suggest that accumulating 60 min of sedentary time seems to be associated with 0.3% higher glucose CV (β = 0.005692, P = 0.071), yet the same duration spent in MVPA tends to be associated with 0.7% lower glucose CV (β = –0.012038, P = 0.086), suggesting a greater impact of MVPA on glycaemic variability. Thus, encouraging reduced sedentary time combined with participation in MVPA may reduce glycaemic variability in healthy adolescents with small variations in blood glucose concentrations. Using CGM, Chapter 6 investigated the acute effect of school-based exercise bouts on postprandial glycaemia and 24 h glycaemic variability in 14 healthy adolescents (6 girls, 12.8 ± 1.0 y, 18.0 ± 1.6 kg∙m−2). The participants performed three experimental conditions in a fixed pre-determined order on three consecutive days: day 1) moderate intensity exercise condition (MIE, 30-min continuous brisk walking); day 2) no-exercise control condition (CON); day 3) high intensity intermittent exercise condition (HIIE, 30-min of 10 × 30-s sprints interspersed with 2.5-min brisk walking bouts). They performed the exercise conditions or no-exercise then consumed three standardised meals (breakfast and lunch at school and dinner at home) at fixed times. Thirty-minute bouts of MIE and HIIE did not change postprandial glycaemia (P ≥ 0.203) or 24-h glycaemic variability (P ≥ 0.281) significantly in this small sample of healthy adolescents. Although non-significant, the reduction in post-breakfast glucose iAUC was moderate for MIE (−0.24 mmol·L−1; P = 0.589; d = 0.77) and large for HIIE (−0.26 mmol·L−1; P = 0.444; d = 0.86) compared with CON. Non-significant, moderate (0.37 mmol·L−1; P = 0.219; d = 0.70) and large (0.42 mmol·L−1; P = 0.203; d = 0.81) increases in post-lunch glucose iAUC were observed for MIE and HIIE compared with CON. Furthermore, the effect size in post-dinner glucose iAUC were trivial to small between conditions, suggesting a short residual effect of exercise lasting for two meals. The mismatch between the probability values and effect sizes was a consequence of the COVID-reduced sample. The ramifications of these exercise effects are unclear and need to be confirmed in a larger sample of adolescents. The last experimental study, Chapter 7, examined the effect of early morning (EM-BC, 08:30) and mid-morning (MM-BC, 10:30) breakfast consumption compared with breakfast omission (BO) on the glycaemic and insulinaemic responses to the second meal (i.e., lunch) in 15 healthy adolescent girls (13.1 ± 0.8 y, 19.8 ± 3.1 kg∙m−2) who skipped breakfast habitually. The main finding from this study was that MM-BC significantly reduced post-lunch glucose tAUC (–10%; P = 0.002, d = 0.68) and iAUC (–36%; P < 0.001, d = 1.44) compared with BO, with moderate to large effects. However, the EM-BC resulted in non-significant reductions in post-lunch glucose tAUC (–5%; P = 0.195, d = 0.36) and iAUC (–15%; P = 0.077, d = 0.52) compared with BO, with small to moderate effects. Furthermore, MM-BC resulted in moderate reductions in post-lunch peak glucose compared with both BO (–1.03 mmol·L−1; P = 0.001, d = 0.74) and EM-BC (–1.03 mmol·L−1; P = 0.001, d = 0.74), with no significant difference between EM-BC and BO (P = 1.00, d = 0.001). Lastly, MM-BC resulted in a moderate, significant reduction in glycaemic variability across the 6 h experimental period compared with BO (–4.4%; P = 0.008, d = 0.56) yet the difference was trivial between EM-BC and BO (–1.1%; P = 1.00, d = 0.14). Although a second-meal effect was not found after EM-BC, the results of this study are important because they demonstrate that the timing of breakfast or the interval between the 1st and 2nd meals may be important for breakfast skipping girls. In summary, the information presented in this thesis extends the knowledge on glycaemic variability in relation to daily PA, exercise bouts and breakfast timing interventions in healthy adolescents. This thesis demonstrates an acceptable performance of FreeStyle Libre and the practicality of using this tool under free-living conditions with adolescents. This thesis provides further evidence of the potential benefit of engaging in daily MVPA and reducing sedentary time to lower glycaemic variability. In addition, thirty-minute bouts of MIE and HIIE reduced postprandial glycaemic response to a breakfast meal consumed in close proximity to exercise, but not to lunch or dinner, suggesting a short-term effect of exercise on glycaemia. Finally, consuming breakfast in the mid-morning (e.g., during the school break) may promote the metabolic health of girls who habitually skip breakfast by moderating the post-lunch glycaemic response.8 0Item Restricted Health Behaviours and Educational Outcomes among Australian University Students(Saudi Digital Library, 2023-10-20) Babaeer, Lena; Gomersall, Sjaan; Stylianou, MichalisYoung people may encounter several challenges when transitioning to higher education. Failure to navigate this transition successfully may contribute to the development of poor health behaviours, which in turn can impact university students’ current, and future, health and educational success. There is a growing body of literature examining relationships between selected health behaviours and educational outcomes (EO) in university students. However, understanding of these relationships is in its infancy, and there are gaps in the existing literature that limit this understanding. These gaps include a lack of knowledge about how health behaviours change over time and during and over academic years, a lack of consideration of confounding factors in analyses, and little attention devoted to qualitative investigations in this area. Other shortcomings of relevant work include lack of consideration of EO other than grade point average (GPA; e.g., graduation rate) and several major methodological issues (e.g., using self-reports measures). To date, no study has examined the relationships between health behaviours and EO qualitatively and few studies have been conducted within the Australian higher education context. This thesis has been informed by a conceptual framework developed by the World Health Organisation (WHO) that describes the potential causal relationships between health behaviours and EO. Guided by this framework, the overarching aim of this thesis was to explore (a) the relationships between health behaviours and EO, and (b) perceptions of health behaviours and EO, among Australian undergraduate university students. Study 1 (Chapter 3) involved a systematic review that aimed to synthesise the existing evidence from studies examining quantitative associations between physical activity (PA), sedentary behaviour (SB), and EO. The quality of included studies was assessed and data were synthesised using an approach considering the consistency and strength of reported associations. Among 35 included studies, most were rated as poor quality (63%) and used self-report measures of PA and SB (97%) and EO (68%). Findings indicated mixed results for the associations between PA, SB, and EO, with grades/GPA being the only EO examined. Studies 2 and 3 (Chapters 4 and 5) aimed to explore cross-sectional and longitudinal associations between PA, SB and EO (Study 2), and dietary intake, alcohol consumption and EO (Study 3), respectively, in first-year Australian university students. Participants (n=80) took part in three data collection points (semesters 1- 3) that included self-reported and device-based PA and SB, and self-reported dietary patterns and intake. Objective EO variables (corresponding semester GPA, overall GPA, graduation status) were extracted from academic records. Multivariate analyses of Study 2 demonstrated that self-reported SB was negatively associated with semester GPA at time point three (β = -0.224, 95%CI: -0.446 ‒ -0.001). Study 3 findings showed a positive association between serves of vegetables and semester GPA at time point two (β = 0.26, 95% CI: 0.034 ‒ 0.481) and over time (β = 0.116, 95% CI: 1.001 ‒ 1.260). Study 4 (Chapter 6) used a qualitative approach incorporating semi-structured focus groups to explore university students’ perceptions about (1) factors that influence their health behaviours and (2) the relationships between health behaviours and EO. Twelve focus groups were conducted with 37 students, and data were initially analysed using an inductive thematic approach, followed by a deductive approach that involved mapping themes on the abovementioned WHO framework. Research question one findings identified several themes that influence students’ health behaviours at the micro (knowledge and skills; personal attributes; socio-demographic characteristics; time), meso (geographic location; university; social influences), and macro (COVID-19 related policies and restrictions) levels. Research question two findings identified two themes. The first theme related to relationships between health behaviours and short-term EO, where students described links between health behaviours and overall grades and other indicators of academic performance. The second theme related to factors perceived to mediate the relationships between health behaviours and EO, with students describing both positive and negative influences of health behaviours on attendance and concentration, motivation to study, and quality of study. Overall, informed by a framework situated within an educational context, this thesis contributes towards a better understanding of the relationships between university students’ health behaviours and EO. The unique contributions of this thesis to the existing body of knowledge include examining longitudinal associations, considering a wide range of potential confounding factors and EO indicators, and incorporating qualitative student perspectives of the relationships of interest. The thesis’ findings highlight that some health behaviours (i.e., sleep, SB and healthy eating) may be more important than others when examining associations with EO, and that addressing potential confounding factors is important for accurately understanding relevant associations. Further, findings point to the importance of timely interventions to support students' health behaviours to optimise both health outcomes and EO, which may benefit from tailored multi-level strategies, targeting multiple health behaviours (as health behaviours are interrelated), and addressing modifiable barriers common across health behaviours (e.g., improving time management skills).16 0Item Restricted EVALUATION OF THE THEORY OF PLANNED BEHAVIOR TO DETERMINE PHYSICAL ACTIVITY IN SAUDI FEMALE ADOLESCENTS(ProQuest, 2023-07-27) Alali, Muna Ali H; Robbins, LorraineBackground and Significance: The significant increase in obesity rates among Saudi female adolescents is a major public health concern. The main factor linked to the high prevalence of obesity among Saudi female adolescents is that only 12.9% attain the World Health Organization (WHO) recommendation calling for 60 minutes/day of moderate to vigorous physical activity (MVPA). The low level of physical activity (PA) among Saudi female adolescents could be attributed to several psychosocial factors that stem from the culture and environment of Saudi Arabia. Understanding these factors is essential to effectively address the low PA problem and plan an intervention. Framework: The conceptual framework for this study was the Theory of Planned Behavior (TPB). Purpose: The primary purpose of the cross-sectional study was to examine the relationship between self-reported PA and TPB psychosocial factors, including attitude toward PA, subjective norms, perceived behavioral control (PBC), and PA intention among Saudi female adolescents in the Eastern Region, Saudi Arabia. Sample: A convenience sample of 329 Saudi female adolescents’ (aged 13–18 years) was recruited from intermediate and high schools in the Eastern Region, Saudi Arabia. Methods: Adolescents from all-female public schools in the Eastern Region of Saudi Arabia were recruited. Administrators in each school sent a link to parents of the students to request parents’ consent for their daughters to participate. Eligible adolescents were asked to complete an online TPB questionnaire and Physical Activity Questionnaire for Adolescents (PAQ-A) via Qualtrics. SPSS was used to calculate descriptive statistics. Mplus was used to conduct Structural Equation Modeling (SEM). Results: The mean age of participants in the study was 15.7 years. Among participants, 14.2% were overweight and 7.3% were obese. Mean PA score was 1.8 (SD = 0.74), indicating low PA level. The structural model exhibited an acceptable fit to the data [x2(217) = 412.28, p < 0.001, RMSEA = .05 with 90% CI [.04-.06], CFI = .93, TLI = 0.92 SRMR= .0.05]. The model explained (53%) and (21%) of the variance in PA intention and PA, respectively. The strongest predictor of adolescents’ intention was attitude (B=0.43, p<.001) followed by PBC (B=0.36, p<.001). Moreover, the female adolescents’ attitude (B=0.17, p<0.01), and PBC (B=0.14, p<0.01) had significant indirect effects on self-reported PA through intention. Additionally, intention (B=0.40, p<0.001) had a direct effect on PA. The model did not support the indirect relationship of SN. However, the study found that SN moderated the intention-PA. The interaction effect was statistically significant (B=0.47, p<.01, 95% CI=0.15-0.78). Moreover, only father education had a significant negative relationship with PBC (B=-0.13, p<.05). Conclusions: The results suggest that attitude, PBC and PA intention are psychosocial factors that collectively tie with PA among Saudi female adolescents. The nuanced understanding derived from TPB-based modeling here can help in developing effective interventions to promote PA in these at-risk female adolescents. Implications: The findings demonstrate the significant contributions of TPB’s psychosocial factors in predicting PA intention and PA among Saudi female adolescents. These results provide needed information for nurses, health professionals, and researchers to develop and test a theory-based intervention to promote PA and reduce obesity-related diseases for Saudi female adolescents. Moreover, nurses can advocate for school policies targeted toward improving PA in order to prevent and decrease childhood obesity.20 0Item Restricted 24-Hour Movement Guidelines and Cardiorespiratory Fitness in Relation to Cardiovascular Disease Risk Factors in Adolescents from Saudi Arabia(University of Exeter, 2022) Alkhraiji, Mohummed Hamad; Williams, Craig A; Barker, Alan RPhysical activity in the form of moderate-to-vigorous physical activity (MVPA), sedentary behaviour in the form of recreational screen time (ST), and sleep, are individually associated with cardiovascular disease (CVD) risk factors in adolescents. Commonly, researchers investigate these three movement behaviours in relation to CVD risk factors in isolation. However, after the launch of the Canadian 24-Hour Movement Guidelines for children and youth, there have been calls to integrate all three 24-hour behaviours (PA, ST, & sleep). Furthermore, a scientific statement from the American Heart Association highlights the importance of cardiorespiratory fitness (CRF) as a measurement for health screening in children and adolescents as CRF is a strong predictor of CVD risk. Previous studies have individually explored how the 24-hour movement guidelines or CRF are associated with CVD risk factors in adolescents; however, which of the two (24-hour movement guidelines or CRF) is more strongly associated with CVD risk factors in adolescents is unknown. Currently, most studies have been conducted in North America and Europe, with the Middle East neglected, including Saudi Arabia, which has a very different lifestyle, environment, climate, school system, and culture compared to North America and Europe. Therefore, to address this gap in the literature in the context of Saudi Arabia, the studies included in this thesis aimed to investigate the prevalence of 24-hour movement guidelines and CRF and their relationship with CVD risk factors in adolescents from Saudi Arabia aged 12–15 years old. Chapter 4 narratively reviewed movement guidelines and CRF in relation to CVD risk factors in children and adolescents from the Gulf Cooperation Council Countries, which indicated gaps in the literature investigating the 24-hour movement guidelines. In addition, Chapter 4 highlighted that there is poor evidence for an association between single movement guidelines and CRF with multiple CVD risk factors; most studies have only examined associations with weight status. Chapter 5 examined the reliability and validity of using the Global School-Based Student Health Survey (GSHS) to assess the 24-hour movement guidelines in (n = 120; 50% females) adolescents aged 12–15 years old, from Saudi Arabia and found acceptable reliability and validity. In Chapter 6, the GSHS was used to examine the prevalence of the 24-hour movement guidelines and their associations with overweight/obesity in a sample of (n = 4224; 52% females) participants aged 12–15 years old. The results indicated that only 2.7% achieved the recommended 24-hour movement guidelines and highlighted weak, non-significant associations with the risk of overweight/obesity. In Chapter 7 a subsample of (n = 120; 50% females) participants aged 12–15 years old from the study in Chapter 6 underwent a 24-hour movement guidelines assessment using GENEActiv accelerometers (for MVPA and sleep) and the GSHS (for ST). In addition, CRF was assessed using the Progressive Aerobic Cardiovascular Endurance Run test, and fasting blood samples, blood pressure, and anthropometrics were collected. None of the adolescents in this subsample met all three of the 24-hour movement guidelines, and there were no favourable significant associations with individual or clustered CVD risk factors. In addition, few males (16%) and almost half of the female (46.3%) participants had a healthy CRF. However, in males only, having a CRF was significantly and negatively associated with waist circumference (WC) and clustered CVD risk. Collectively, the results presented in this PhD thesis contribute to enhancing the literature in four ways. Firstly, it demonstrates that there is a lack of studies on the 24-hour movement guidelines and CRF in relation to CVD risk factors for adolescents from the Gulf Cooperation Council countries. Secondly, it is the first study to examine a questionnaire for its reliability and validity to measure the 24-hour movement guidelines, which found an acceptable reliability and validity. Thirdly, it shows that via a questionnaire few adolescents (2.7%) from Saudi Arabia are meeting the 24-hour movement guidelines, which is not significantly associated with being at risk of overweight/obesity. Lastly, it shows that when using device-based accelerometry, none of the adolescents from Saudi Arabia are meeting the 24-hour movement guidelines, which is not significantly associated with individual or clustered CVD risk factors profiles in both sexes. Moreover, healthy CRF was not significantly associated with individual or clustered CVD risk factors in females, while in males, healthy CRF was only significantly and inversely associated with WC and clustered CVD risk factors. Based on the above findings, it is suggested that 24-hour movement guidelines are not favourable strongly associated with individual or clustered CVD risk factors in adolescents of both sexes from Saudi Arabia. In addition, in females it appears that there are no significant associations between CRF and individual or clustered CVD risk factors. Initiatives should be developed to encourage male adolescents from Saudi Arabia aged 12–15 years old to achieve a healthy CRF to reduce the risk of WC and clustered CVD risk factors. However, future longitudinal studies with larger sample sizes would enable further insight into the associations between 24-hour movement guidelines and CRF in relation to CVD risk factors in adolescents from Saudi Arabia and should provide specific recommendations for both sexes.26 0