Saudi Cultural Missions Theses & Dissertations
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Item Restricted Age-Varying Associations Between Childhood Abuse and The Risk of Obesity Across Adulthood: Examining Data from The National Longitudinal Study of Adolescents to Adult Health(Claremont Graduate University, 2025) Abudawood, Mohammed; Xie, BinChildhood abuse is a significant early-life stressor linked to adverse health outcomes such as obesity across adulthood. This study examines how the association between childhood abuse (physical, emotional, and sexual) and obesity risk varies with age, using data from Waves I–V of the National Longitudinal Study of Adolescents to Adult Health (Add Health). Utilizing Time-Varying Effect Modeling (TVEM), the study identifies specific developmental periods during which the relationship between childhood abuse and obesity risk is strongest and investigates the moderating role of gender. The study found that all forms of childhood abuse are associated with elevated obesity risk across the life course, with distinct patterns over time. Physical abuse showed a stronger impact on obesity risk during late adolescence and early adulthood, with a resurgence of influence in later adulthood. Emotional abuse had a positive and long-lasting association with obesity risk from young adulthood into established adulthood. Sexual abuse was linked to increased obesity risk emerging in late adolescence, early adulthood, and established adulthood, with females experiencing particularly pronounced effects in early adulthood. These results highlight the temporal dynamics of childhood abuse on obesity risk across adulthood, offering critical insights for the timing and tailoring of prevention and intervention strategies. The study underscores the need for trauma-informed public health policies that address childhood abuse as a risk factor for obesity across adulthood, particularly at high-risk age windows. By identifying when and for whom the abuse-obesity link is strongest, this study informs more effective prevention strategies and health policies to mitigate long-term obesity risk among survivors of childhood abuse.9 0Item Restricted UNDERSTANDING THE RELATIONSHIP BETWEEN WEIGHT MANAGEMENT SUCCESS AND FOOD CRAVINGS: INVESTIGATING STRATEGIES(University of Illinois Urbana-Champaign, 2027-12-20) Alfouzan, Nouf; Nakamura, ManabuIntroduction: Obesity and its related comorbidities have become one of the significant threats to public health. While sustained weight loss can mitigate these comorbidities, achieving and maintaining weight loss remains challenging. One of the significant challenges in sustaining weight loss is managing food cravings, as uncontrolled cravings are associated with increased intake of calorie-dense foods and subsequent weight regain. The goals were to determine the impact of weight loss and maintenance on food cravings and identify effective strategies for managing food cravings that could prevent weight regain. The objective of study 1 was to determine the associations of factors such as food cravings and eating habits with large variations in weight loss and maintenance outcomes. The objective of study 2 was to evaluate the long-term change in food cravings, whether food cravings changes persist during weight maintenance, and explore the relationship between food cravings changes and weight loss outcomes. The objective of the final study was to determine whether an avoidance strategy or an inclusion strategy is more effective in reducing food cravings and achieving a greater magnitude of weight loss. Methods: Study 1 was a one-year follow-up study conducted after completing a one-year dietary weight loss program. Twenty-two participants entered the follow-up phase and weighed themselves daily using Wi-Fi scales. Self-reported questionnaires assessing food cravings and eating habits were collected at 12 and 24 months. In study 2, thirty participants with a BMI of 25 kg/m² enrolled in a one-year weight loss dietary program, EMPOWER, followed by one year of weight maintenance. Self-reported food craving questionnaires were completed at baseline, 6, 12, 18, and 24 months. At 12 months, participants reported their experience using the "inclusion strategy" for managing food cravings and rated its frequency and effectiveness in supporting weight loss goals and controlling food cravings. Daily self-weighing was recorded using Wi-Fi scales. In the final study, sixty-three adults with a BMI of 28 kg/m², who reported moderate food cravings and the consumption of craved foods a few times a week, participated in a 3-month EMPOWER program. Participants were randomized into one of two food craving management strategies: avoidance or inclusion. The avoidance strategy involves completely avoiding craved foods by reducing their availability and accessibility, while the inclusion strategy incorporates small portions of craved foods within well-balanced meals and avoids their consumption between meals. Self-reported food craving questionnaires were completed at baseline and 3 months, along with bi-weekly self-reported treatment adherence. Daily self-weighing was reported using Wi-Fi scales. Body composition and anthropometric measurements were taken at baseline and 3 months. Monthly self-reported dietary intake was assessed, and weekly feedback messages from nutrition coaches were provided to monitor progress in weight loss and food craving management. Results: In study 1, 19 out of 22 (86.3%) completed the questionnaires at 12 and 24 months. Control food cravings at 12 and 24 months was significantly associated with weight loss outcomes; those in the >5% weight loss group had higher food craving control compared to the <5% group (3.23 vs. 2.72, p = 0.03; 3.48 vs. 2.72, p = 0.01, respectively). Self-perceived implementation of maintaining consistent portion sizes significantly correlates with weight loss outcomes at 24 months (r=0.76, p=0.0001). In study 2, out of 30 participants, 24 (80%) remained in the program at 12 months with an average (SD) weight loss of -7.9 (7.2 %) and 20 (66.7%) completed the program at 24 months with a mean weight loss of -6.7 (7.5 %). The frequency of general food cravings and cravings for specific foods and craving traits decreased significantly at 12 and 24 months from baseline and remained stable from 12 to 24 months. Changes in food cravings at 6 months predict concurrent and subsequent weight changes at 12, 18, and 24 months. Participants who implemented the inclusion strategy (n = 16) experienced significantly greater weight loss (-9.9% vs. -3.7%, p = 0.04), reduced cravings for high-fat foods (-0.50 vs. -0.09, p = 0.02), and sweet foods (-1.02 vs. -0.38, p = 0.028) compared to non-strategy users (n = 8) at 12 months. In the final study, 56 of 63 participants (88.9 %) completed the 3-month EMPOWER program, with a mean weight loss of -3.55(3.21 %). There was no significant difference in weight loss between the groups (p=0.67), with the avoidance group's average weight loss of -3.73 (3.34 %) (n=28) and the inclusion group's average weight loss of -3.36(3.34 %) (n=28). Compared to the avoidance group, the inclusion group showed greater reductions in cravings for carbohydrates (p = 0.01), high-fat foods (p = 0.03), and general food cravings (p = 0.05). The inclusion group also had significant improvements in global trait scores (p = 0.04) and specific traits such as "anticipation of relief from the negative state" (p = 0.03), "craving as a physiological state" (p = 0.04), and "guilt from cravings" (p = 0.04). In the inclusion group, craving frequency and strength steadily decreased from Week 2 to Week 12, whereas in the avoidance group, cravings initially decreased from Week 2 to Week 4 but then increased. Conclusion: In study 1, reduced food cravings were correlated with successful weight maintenance. In study 2, food cravings and cravings for specific foods decreased during weight loss, and remained stable during weight maintenance, with craving reduction demonstrating a strong correlation to successful weight loss and maintenance. In the final study, the inclusion strategies resulted in a greater reduction in food cravings and cravings for specific foods compared to the avoidance strategy.15 0Item Restricted UNDERSTANDING THE RELATIONSHIP BETWEEN WEIGHT MANAGEMENT SUCCESS AND FOOD CRAVINGS: INVESTIGATING STRATEGIES(UNIVERSITY OF ILLINOIS URBANA CHAMPAIGN, 2024) ALFOUZAN, NOUF; NAKAMURA, MANABUIntroduction: Obesity and its related comorbidities have become one of the significant threats to public health. While sustained weight loss can mitigate these comorbidities, achieving and maintaining weight loss remains challenging. One of the significant challenges in sustaining weight loss is managing food cravings, as uncontrolled cravings are associated with increased intake of calorie-dense foods and subsequent weight regain. The goals were to determine the impact of weight loss and maintenance on food cravings and identify effective strategies for managing food cravings that could prevent weight regain. The objective of study 1 was to determine the associations of factors such as food cravings and eating habits with large variations in weight loss and maintenance outcomes. The objective of study 2 was to evaluate the long-term change in food cravings, whether food cravings changes persist during weight maintenance, and explore the relationship between food cravings changes and weight loss outcomes. The objective of the final study was to determine whether an avoidance strategy or an inclusion strategy is more effective in reducing food cravings and achieving a greater magnitude of weight loss. Methods: Study 1 was a one-year follow-up study conducted after completing a one-year dietary weight loss program. Twenty-two participants entered the follow-up phase and weighed themselves daily using Wi-Fi scales. Self-reported questionnaires assessing food cravings and eating habits were collected at 12 and 24 months. In study 2, thirty participants with a BMI of 25 kg/m² enrolled in a one-year weight loss dietary program, EMPOWER, followed by one year of weight maintenance. Self-reported food craving questionnaires were completed at baseline, 6, 12, 18, and 24 months. At 12 months, participants reported their experience using the "inclusion strategy" for managing food cravings and rated its frequency and effectiveness in supporting weight loss goals and controlling food cravings. Daily self-weighing was recorded using Wi-Fi scales. In the final study, sixty-three adults with a BMI of 28 kg/m², who reported moderate food cravings and the consumption of craved foods a few times a week, participated in a 3-month EMPOWER program. Participants were randomized into one of two food craving management strategies: avoidance or inclusion. The avoidance strategy involves completely avoiding craved foods by reducing their availability and accessibility, while the inclusion strategy incorporates small portions of craved foods within well-balanced meals and avoids their consumption between meals. Self-reported food craving questionnaires were completed at baseline and 3 months, along with bi-weekly self-reported treatment adherence. Daily self-weighing was reported using Wi-Fi scales. Body composition and anthropometric measurements were taken at baseline and 3 months. Monthly self-reported dietary intake was assessed, and weekly feedback messages from nutrition coaches were provided to monitor progress in weight loss and food craving management. Results: In study 1, 19 out of 22 (86.3%) completed the questionnaires at 12 and 24 months. Control food cravings at 12 and 24 months was significantly associated with weight loss outcomes; those in the >5% weight loss group had higher food craving control compared to the <5% group (3.23 vs. 2.72, p = 0.03; 3.48 vs. 2.72, p = 0.01, respectively). Self-perceived implementation of maintaining consistent portion sizes significantly correlates with weight loss outcomes at 24 months (r=0.76, p=0.0001). In study 2, out of 30 participants, 24 (80%) remained in the program at 12 months with an average (SD) weight loss of -7.9 (7.2 %) and 20 (66.7%) completed the program at 24 months with a mean weight loss of -6.7 (7.5 %). The frequency of general food cravings and cravings for specific foods and craving traits decreased significantly at 12 and 24 months from baseline and remained stable from 12 to 24 months. Changes in food cravings at 6 months predict concurrent and subsequent weight changes at 12, 18, and 24 months. Participants who implemented the inclusion strategy (n = 16) experienced significantly greater weight loss (-9.9% vs. -3.7%, p = 0.04), reduced cravings for high-fat foods (-0.50 vs. -0.09, p = 0.02), and sweet foods (-1.02 vs. -0.38, p = 0.028) compared to non-strategy users (n = 8) at 12 months. In the final study, 56 of 63 participants (88.9 %) completed the 3-month EMPOWER program, with a mean weight loss of -3.55(3.21 %). There was no significant difference in weight loss between the groups (p=0.67), with the avoidance group's average weight loss of -3.73 (3.34 %) (n=28) and the inclusion group's average weight loss of -3.36(3.34 %) (n=28). Compared to the avoidance group, the inclusion group showed greater reductions in cravings for carbohydrates (p = 0.01), high-fat foods (p = 0.03), and general food cravings (p = 0.05). The inclusion group also had significant improvements in global trait scores (p = 0.04) and specific traits such as "anticipation of relief from the negative state" (p = 0.03), "craving as a physiological state" (p = 0.04), and "guilt from cravings" (p = 0.04). In the inclusion group, craving frequency and strength steadily decreased from Week 2 to Week 12, whereas in the avoidance group, cravings initially decreased from Week 2 to Week 4 but then increased. Conclusion: In study 1, reduced food cravings were correlated with successful weight maintenance. In study 2, food cravings and cravings for specific foods decreased during weight loss, and remained stable during weight maintenance, with craving reduction demonstrating a strong correlation to successful weight loss and maintenance. In the final study, the inclusion strategies resulted in a greater reduction in food cravings and cravings for specific foods compared to the avoidance strategy.9 0Item Restricted Bariatric Surgery and Its Impact on Taste Perception and Preference: A Systematic Review(University of Nottingham, 2024-09-02) Alsaud, Alhanoof; Eldeghaidy, SallyBackground: Changes in taste perception and food preferences could play a significant role in driving dietary modifications and facilitating weight loss following bariatric surgery. These sensory alterations may influence the types of food patients are inclined to consume post-surgery, potentially leading to healthier eating patterns that support sustained weight reduction. Objective: to assess variations in taste thresholds, in the intensity and quality of taste sensations and in changes to food preferences following bariatric surgery. Methodology: A systematic review was conducted using databases such as PubMed, Scopus, and Web of Science to identify studies examining changes in taste perception and preferences following bariatric surgery. Inclusion criteria were set to include studies with pre- and post-surgery taste perception and preference measurements. Data were extracted and synthesised to highlight changes assess variations in taste perception and food preferences. Result: The review included 12 studies, found that bariatric surgery lead to significant taste changes in taste thresholds, intensity and quality. Alterations in taste thresholds, including increased or decreased sensitivity for sweetness, bitterness, and saltiness, and the hedonic value of food that reduce enjoyment of high-calorie and high-fat food were commonly reported. Changes in food preference often shifted toward healthier choices, with reduced cravings for sweet and fat and increased intake of fruits and vegetables. However, these changes were not always sustained over time. Potential mechanisms also mentioned which involve hormonal changes, neurobiological adaptations in brain reward system, and inflammatory responses. Conclusion: Current evidence indicates that bariatric procedures lead to significant changes in taste perception and food preference, which may play a critical role in supporting the long-term maintenance of weight loss after bariatric surgery. Future research should include extended follow-up and investigate the mechanism behind this change to better understand the long-term effect of taste alteration and dietary changes.14 0Item Restricted An evaluation of the Rashaka Initiative: a school-based obesity intervention in Makkah City, Saudi Arabia(University of Technology Sydney, 2024-03) Banany, Mohammed; Sibbritt, David; Gebel, KlausBackground: Childhood overweight and obesity are public health issues worldwide. In Saudi Arabia, in 2016/2017 the Rashaka Initiative, a national school-based, multicomponent, weight-related intervention, was launched to decrease the prevalence of obesity among students by 5% within five years. Neither the development stage of the initiative nor its implementation has been evaluated to explore its processes and outcomes. Aim: This study was aimed at evaluating the implementation of the Rashaka Initiative in intermediate and secondary schools in Makkah City, Saudi Arabia, covering both process and outcome. To this end, the following objectives were pursued: (1) to develop an evaluation framework that can be used to assess the processes and outcomes of the initiative, (2) to determine whether there was a change in students’ body mass indices (BMIs) during the implementation period, and (3) to explore the knowledge and attitudes of the Rashaka stakeholders regarding the perceived barriers and facilitators of implementation in their schools. Methods: This retrospective study, conducted after the implementation of the Rashaka Initiative, was completed in three phases. In phase I, a conceptual framework called the school-based weight-related intervention evaluation framework (SWIEF) was developed by integrating some elements of the program evaluation framework used by the US Centers for Disease Control and Prevention (CDC) with the components of a logic model. In phase II, secondary data from the Rashaka Initiative were analysed. Phase III was a cross-sectional exploration of the Rashaka stakeholders’ knowledge and attitudes as well as what they perceive as facilitators and barriers to implementing the intervention at their schools. Results: The comprehensive literature review yielded a published systematic review (Banany et al. 2024, Systematic Reviews). This systematic review found 11 school-based weight-related intervention studies in the six Gulf Cooperation Council countries (GCC). Despite the methodological limitations of some of these studies, there is preliminary evidence of the possible benefits of school-based interventions on students' weight and associated lifestyle factors in these countries. A review of the literature also facilitated the development of the SWIEF. The analysis of the secondary data revealed a significant reduction in BMI (p<0.001) across schools that participated in the Rashaka Initiative over two school years (2016/17 and 2018/19). However, this reduction was not associated with the school environmental factors attributed to the initiative. The study findings found that students’ BMIs decreased more considerably in girls’ and intermediate schools than in boys’ and secondary schools (p<0.001 and p=0.031, respectively). The cross-sectional study indicated that significantly better knowledge of risk factors and interventions for childhood obesity was exhibited by female Rashaka stakeholders (vs their male counterparts), stakeholders who completed tertiary education (vs those with lower education levels) and stakeholders engaged in the initiative for more than two years (vs participants who joined more recently) (p<0.001, p<0.007 and p<0.033, respectively). School health counsellors had more positive attitudes towards children’s health and weight than principals (p<0.008). Significantly more favourable attitudes towards the Rashaka intervention were also found among female stakeholders (p<0.011) and those with better knowledge of the initiative’s objectives, components, activities, and outcomes (p<0.049). Among the stakeholders, 73% perceived collaboration with different government and private sector institutions as the most common facilitator of the Rashaka implementation at their schools, while 69% perceived a lack of time as the main barrier. Conclusions: Addressing childhood obesity is a public health priority that requires substantial efforts from all relevant key stakeholders in Saudi Arabia. The evidence derived in this thesis revealed that the Rashaka Initiative has yet to satisfy its objectives. Future studies should be more rigorous, theory-based, and holistic to tackle obesity among school students. Evaluations of school-based obesity interventions should use control groups, validated and reliable measures and rigorous data analysis. Long-term monitoring of the implemented interventions is highly recommended for their improvement and sustainability.51 0Item Restricted The Impact of Zinc Levels on Taste Change and Hair Loss Following Bariatric Surgery and Reporting of Dietary Compliance to Weight Loss Interventions(The University of Nottingham, 2024-06-17) Mozaffar, Boshra; Idris, IskandarCurrently, there is significant interest in the effective treatment of obesity, particularly the implementation of a very low-calorie diet (VLCD) and the use of bariatric surgery (BS) which is a well-established long-term treatment. However, much of the contemporary research has noted that patients who have undergone bariatric surgery have reported unexplained side effects, such as a change in their sense of taste which may impact dietary compliance post- surgery. Additionally, there is limited research concerning long-term compliance with a very low-calorie diet which is a crucial aspect of pre-and post-bariatric surgery eating requirement. This thesis is divided into two sections: the first section investigates the links between taste change and zinc following BS, and the second section examines patients’ compliance with a VLCD. The over-arching theme of the thesis focuses on the speculative association of taste and hair loss following bariatric surgery with decreased circulating zinc levels, which might affect compliance to post-surgery eating requirements and the reporting of compliance to significant calorie restriction. In the initial part of the first section, a systematic review was conducted to collect evidence regarding the role of zinc in the development of taste disorders among patients who had undergone bariatric surgery and those who had not. This study used PRISMA guidelines to conduct systematic reviews of several electronic bibliographical databases, including EMBASE, PubMed, AMED, and MEDLINE, for studies concerning the effects of BS on taste, the effects of BS on zinc levels, and the effect of zinc replacement on taste. The results from this systematic review demonstrated that, according to the findings of qualitative research (conducted via questionnaires), taste change was observed in the majority of patients within a year following bariatric surgery. However, experimental investigations did not yield statistically significant evidence of taste alteration. A total of twelve investigations were conducted to examine the occurrence of zinc deficiency following bariatric surgery (BS), VI which revealed a notable reduction in zinc levels that persisted for six months post-surgery. The administration of zinc sulphate was found to be efficacious in enhancing taste perception in patients, apart from those with a cancer diagnosis who did not exhibit any improvement in taste following the dispensation of zinc supplements. Given that zinc deficiency and taste disorders occur in repeated cases at approximately the same time, this study hypothesises the existence of a potential relationship between these two factors. Therefore, the subsequent section of this work examines the connection between zinc and taste change following sleeve gastrectomy (SG) and gastric bypass (GB) via a single- centre, prospective cohort study conducted at King Abdullah Medical City (KAMC) in Saudi Arabia (Makkah). Forty-three patients were selected, consisting of eighteen gastric bypass patients and twenty-five patients who had undergone sleeve gastrectomy (SG). The duration of the follow-up period spanned a length of six months. The assessment of taste alteration was conducted via the utilisation of a validated questionnaire and implementation of the taste strips technique. Additionally, the study involved the measurement of serum zinc levels and salivary flow rate for all of the participants. Following the administration of the questionnaire, the results of this study demonstrate that patients who had undergone gastric bypass (GB) surgery exhibited a higher prevalence of hypogeusia (at the three-month mark) when compared with those who underwent sleeve gastrectomy (SG), with percentages of 72.0% and 36.0% respectively (p=0.03). However, no significant difference in hypogeusia prevalence was discovered between the two groups at the six-month mark, with percentages of 56.0% for GB and 45.0% for SG patients (p=0.74). However, when taste strips were utilised, there was no notable disparity in the occurrence of hypogeusia between patients with GB and SG at the three-month point (44.4% versus 36.0%,p=0.75). Nevertheless, at six months, a higher proportion of patients with GB reported experiencing hypogeusia compared to SG patients (44.0% vs. 11.0%, p=0.052). The study observed a significant decrease in zinc levels among GB patients, from the initial measurement of 85.6±16.9μgm /dl to the six-month measurement of 67.5±9.2μgm/dl. Conversely, SG patients reported an increase in zinc levels from the baseline measurement of 76.9±11.4 to the six-month measurement of 84.9±21.7μgm/dl. A decrease in the salivary flow rate was noted in 66.0% and 72.0% of individuals with GB and SG, respectively, after 3 months, and in 47.0% and 70.0%, respectively, after 6 months. Hair loss was noted as an additional side-effect following BS; however, the underlying causes and factors of this condition remain unidentified. Therefore, a subsequent section investigates the potential association between hair loss and decreased circulating zinc levels following BS and the differences between SG and GB patients. The findings of the study revealed that the prevalence of hair loss among patients who underwent GB was double that of SG. Specifically, at three months post-surgery, the percentage of hair loss was 66.6% in the GB group and 32% in the SG group, indicating a significant difference between the two groups (P = 0.025). Furthermore, at six months post-surgery, the percentage of hair loss increased to 75% among GB patients, while it decreased to 20% among SG patients. The findings also indicated a statistically significant difference between the groups, with a p-value of 0.001. This research established that individuals who had undergone bariatric surgery and experienced subsequent hair loss displayed reduced zinc levels compared to the established reference value and that, in this patient population, females were more susceptible to hair loss than males. These findings suggest that hair loss is a frequently observed adverse outcome that can occur following both types of surgeries; however, it has been shown that GB patients are inclined to VIII experience a higher degree of hair loss, which has been linked to lower levels of zinc in their blood. In the final part of this section, a study assessed the effective zinc doses for taste disorder treatment to inform future clinical guidelines and studies regarding the use of zinc as a remedy for taste disorders following BS. A systematic review and meta-analysis were conducted regarding the effectiveness of zinc supplementation in taste disorder treatment following the guidelines outlined in the PRISMA Statement. A comprehensive search of four electronic bibliographic databases (Ovid MEDLINE, Ovid Embase, Ovid AMAD, and PubMed) was conducted. This review has been duly recorded with PROSPERO and assigned the unique identification number CRD42021228461. The results demonstrate that zinc supplementation, when administered at high dosages ranging from 68 to 86.7 mg/d for a duration of up to six months, is an efficacious intervention for taste abnormalities in individuals with zinc deficiency, idiopathic taste disorders, and those with taste disorders resulting from chronic renal failure. The second section of this thesis concerns a clinical study involving thirty-five, healthy, middle-aged male volunteers and is designed to investigate and document the consumption of an extra calorie allowance derived from conventional foods or only from vegetables and nuts (up to 200kcal/day). Additionally, this study employed two distinct evaluation methodologies to analyse the macronutrient composition of these dietary additions to evaluate VLCD compliance for up to six weeks. The results revealed that patients following a very low-calorie diet (VLCD) who are provided with an additional food allowance from traditional sources or have their food intake confined to vegetables and nuts, frequently consume more calories than the prescribed daily limit. How compliance is reported exhibits substantial variation depending on the method of monitoring employed. The data presented in the conclusion of this thesis suggest that: firstly, decreased circulating zinc level following bariatric surgery is directly correlated to taste change, low salivary flow and hair loss, and that high doses of zinc supplementation are an effective remedy for taste change; and, secondly, patients fail to strictly adhere to VLCD. Additionally, the data presented by this thesis suggests that future research concerning the effectiveness of zinc supplementation in taste disorder treatment (following bariatric surgery), and additional studies concerning long-term compliance with a very low-calorie diet, are required.39 0Item Restricted Childhood Obesity and Weight Stigma: A Public Health Nutrition Approach(University of Glasgow, 2024-04-20) Abuznada, Salma; Combet, Emilie; Garcia, AdaPoor understanding of obesity, its causes and consequences contribute to weight-related stigma in the UK. Children’s understanding of obesity shapes their views and perceptions towards obesity as a disease, body image, and weight stigma behaviours. Exploring children’s and adolescents’ knowledge, perceptions and views of obesity, weight stigma, and nutrition is essential to establishing effective health promotion programmes that cater to young people’s needs, understanding and perspectives. Successful programmes also need continuous monitoring and evaluation, which are currently lacking in the UK. Perceptions and views around obesity among the public vary in different cultures and among healthcare professionals. These different perspectives lead to debates on defining, managing and treating obesity. Weight stigma research in adults tends to focus on weight stigma due to the poor understanding of obesity both among the public (especially women of white ethnicity) and healthcare professionals rather than children and adolescents. This thesis uses systematic reviews and a mixed-methods approach to explore weight stigma across the age spectrum, including children, adolescents and adults. Furthermore, the research investigates children’s and adolescents’ views on obesity and nutrition knowledge. Study 1 systematically reviewed existing observational, quantitative and qualitative studies focusing on the sources, frequency and implications of weight stigma on children’s and adolescents’ mental health, well-being and eating behaviours. The Preferred Reporting Items for Systematic Reviews and Meta- Analyses (PRISMA) were followed for study selection, screening and data extraction. Synthesis Without Meta-Analysis (SWiM) guidelines were applied to report the synthesis and results. The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies from the National Heart, Lung, and Blood Institute (NHLBI) was used to assess the quality of the included studies. Twenty observational studies were included in the final text analysis. Synthesised evidence highlighted that bullying and victimisation play a fundamental role in developing and perpetuating weight-related stigma. Weight-related bullying was correlated with participants’ low self-esteem. Most of the included studies (N=15/20) were of fair quality (average score 5 to 8), although two were of poor quality (average score 0 to 4), and most of the quality criteria were not met. One of the main gaps identified during the literature search in Study 1 was children and adolescents were poorly represented in the studies, with an overemphasis on white adult women. After identifying existing gaps in the literature (e.g., the overemphasis on recruiting white women), Studies 2, 3 and 4 were developed to explore underrepresented groups and gain a deeper understanding of their views and opinions of obesity and weight stigma. Children’s and adolescents’ views and opinions of obesity and nutrition knowledge were explored in Study 2, using a cross-sectional questionnaire and phone interviews. The questionnaire was structured in six sections, exploring sociodemographic characteristics, anthropometric measurements, views and perceptions of obesity, nutrition knowledge, general health, and eating habits and lifestyle. Online interviews followed a narrative focusing on obesity knowledge and experience, obesity perception and the relationship between nutrition and obesity. Study 2 recruited a total of n=317 participants, 54% boys, 72% White/British, with a median age of 16 years (interquartile range (IQR) 15- 18). There was an overall lack of understanding of obesity and its causes and consequences. There was also a lack of consensus and agreement about whether obesity is a sign of disease, a disease, or merely a body shape. There was agreement that obesity can be a personal responsibility (median=4: likely, IQR 3: neutral – 4: likely). Food knowledge was low, with 83% correctly answering three questions or fewer out of six. Although participants reported and believed that they knew what obesity was, most participants linked obesity to body image and placed the responsibility of having obesity on the individuals or their parents. This can lead to increased stigmatising behaviours and isolation of children and adolescents with obesity. Proper education about obesity is imperative to help support children in understanding the general concepts behind obesity’s complexity as a disease. Study 3 used a cross-sectional questionnaire and phone interviews to explore weight stigma and its implications on weight stigma attitudes and body image perceptions in children. In Study 3 (n=667, 62% boys, 70% White/British, median age 16 years (IQR 15-18)), 50% of participants who experienced weight stigma had a BMI ≥30 kg/m². Almost two-thirds of participants who experienced weight stigma (n=259) said it happened at local community places (e.g., clubs, during extracurricular activities) (n=149, 58%). Over a quarter (n=67,26%) reported that it was extremely harsh. Participants who self-reported having obesity (n=214) experienced more weight stigma (n=114, 53%) than those who believed they have overweight (n=87, 41%) or underweight (n=13, 6%). More than half of the sample (n=408, 61%) were dissatisfied with their body image. Most participants who self-reported having obesity were dissatisfied with their body image, demonstrating a significant relationship between self-reported weight problems ‘underweight, overweight, obesity’ and body image satisfaction levels ‘dissatisfied, neutral and satisfied’". In summary, unsurprisingly, most participants who reported weight stigma had a BMI ≥30 kg/m2. Interestingly, more boys than girls who reported experiencing weight stigma believed there was weight stigma in society. To better understand the contribution and impact of childhood lived experiences of weight stigma on adult perceptions and beliefs around overweight and obesity, Study 4 employed similar methods to Study 3. In Study 4 (n=738, 52% men, 76% White/British, 39% BMI ≥30 kg/m2, median age=26 years (IQR=24-31)), less than a quarter of participants had experienced weight stigma as children (n=154, 21%). More women (n=108/154, 70%) experienced weight stigma during childhood than men (n=46/154, 30%, p≤0.001). Participants were mostly undecided about whether obesity is a disease (median=3: undecided, IQR=1: strongly disagree – 3: undecided). Experiencing weight stigma in childhood was positively associated with parents reporting their children’s weight stigma experiences. Parents dissatisfied with their body image (n=62) were more likely to be dissatisfied with their children’s body image (n=23/62, 37%) than satisfied (n=17/62, 24%). Understanding and awareness of obesity are essential in developing public health strategies and health education programmes that are child-oriented and specific to children and adolescents regarding location and intervention tools. The findings in this thesis highlight the negative impact of weight stigma on children and adolescents' physical and mental health. Moreover, a poor understanding of obesity was evident in this research. The work of this research is beneficial in informing programs explicitly targeting the gaps explored and found. This thesis attempts to improve the knowledge of public and academic domains in elements surrounding perceptions, views, and attitudes regarding obesity and weight stigma, the reasonings behind perceptions, and strategies to address obesity stigmatising behaviour.18 0Item Restricted Metabolic and Bariatric Surgery: Utilization, Statin Discontinuation, and Cardiovascular Risk Stratification in the Modern Era(University of Cincinnati, 2024) Alsuhibani, Abdulrahman; Hincapie, AnaBackground: Bariatric surgery, as a pivotal intervention to treat obesity, has seen dynamic utilization trends over recent years, and the subsequent pharmacological implications, particularly concerning statin discontinuation, hold significance. With the world grappling with the cardiovascular epidemic and its associated mortality, there's an imperative need to understand the cardiovascular outcomes post-bariatric surgery, especially when linked with discontinuation of critical medications like statins. Aims: This dissertation aimed to delineate the trends in bariatric surgery utilization and the corresponding shifts in surgical techniques in the U.S. Furthermore, it sought to understand the patterns and repercussions of statin discontinuation post-surgery, with an emphasis on discerning the risks associated with discontinuing statin therapy, particularly among patients with a history of Atherosclerotic Cardiovascular Disease (ASCVD). Methods: Comprehensive retrospective analyses were conducted utilizing the TriNetX electronic medical records network, spanning the years 2012 to 2021. The trends in bariatric surgeries were examined alongside their procedural variations. In parallel, patients on statin therapy undergoing bariatric surgery were identified, with their subsequent statin discontinuation patterns being analyzed. The consequences of such discontinuations, especially regarding ASCVD events, were also explored, taking into consideration both primary and secondary prevention cohorts. Results: There was a steady upswing in bariatric surgeries until 2018, which saw a decline during 2020 and 2021, coinciding with the COVID-19 pandemic. The surgical landscape depicted a decline in the Roux-en-Y (RYGB) procedure, substituted by an uptake in the sleeve gastrectomy (SG) procedure. Among statin therapy users, 48% of primary prevention and 34.5% of secondary prevention patients discontinued statin therapy within six months post-bariatric surgery. Alarmingly, within a statin therapy discontinuation post bariatric surgery, secondary prevention patients manifested significantly higher ASCVD event rates compared to their primary prevention counterparts. Distinctly, Hispanic/Latino patients exhibited heightened ASCVD risks post-statin discontinuation, as opposed to non-Hispanic/Latino individuals. Conclusion: The trends in bariatric surgery, amidst their shifting preferences, underscore the importance of understanding the aftermath of such surgeries, especially regarding medication discontinuation. The discontinuation of statins post-bariatric surgery, particularly among those with prior ASCVD, poses discernible risks, accentuating the need for individualized, equitable healthcare strategies. Addressing ethnic disparities and ensuring tailored therapeutic approaches based on comprehensive cardiovascular determinants is crucial. Future research endeavors are essential to further finetune these interventions and recommendations.9 0Item Restricted Body Weight and Mortality Risk in Community-Dwelling Older Adults(Monash University, 2024-02-21) Alharbi, Tagrid Abdullah; Owen, Alice; Freak Poli, Rosanne; Ryan, Joanne; Gasevic, DanijelaBackground: Overweight and obesity, generally defined by body mass index (BMI) ≥ 25 kg/m² or large waist circumference (abdominal obesity), is increasingly prevalent among older adults worldwide, however studies of excess weight and the link with mortality risk in older adults have reported mixed findings. Weight change may be a better indicator of mortality risk in older individuals, but large community-based longitudinal studies of older individuals are needed. Aims: To systematically review the association between weight change and all-cause mortality risk in adults aged ≥ 65 years, and to examine the association of weight status, abdominal obesity and weight change with the risk of mortality in community-dwelling older adults aged ≥ 65 years. Methods: A systematic review and meta-analysis conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines to examined the evidence that weight change (loss, gain and fluctuation, measured by weight or BMI) is associated with all-cause mortality. Secondary data analysis was performed using longitudinal data on community-dwelling individuals from the ESPIRIT (France, N=2,017) and ASPREE/ALSOP sub-studies (Australia, N=14,853). The association of self-reported weight loss, objectively measured weight change (loss and gain), weight status, and abdominal obesity with all-cause mortality over a 17-year follow-up period in the ESPIRIT study was explored using Cox proportional-hazard regression. To broaden understanding of the association between BMI in early (at age 18 years) and later (age ≥70 years) adulthood, and their impact on later-life mortality (over a median of 4.7 years in the ASPREE/ALSOP sub-study), Cox proportional-hazard regression was applied. Furthermore, the socio-demographic, lifestyle, and clinical characteristics associated with change in weight status between early (age 18 years) and late (age ≥ 70 years) adulthood were identified. Results: From the systematic review, weight change, particularly weight loss, was found to be associated with a 59% increased risk of mortality compared to stable weight. Longitudinal data analyses found that abdominal obesity was linked to a 49% increased mortality risk compared to non-abdominal obesity, but being overweight was associated with a 20% decreased risk compared to a normal BMI. Self-reported weight loss of >3 kg at baseline was associated with a 52% increase in mortality risk for men only; but both men and women with ≥ 5% objectively measured weight loss had a 24% increased risk of all-cause mortality. Obesity at 18 years, but not in older age, was associated with a 35% increased risk of mortality in later life. Compared to participants with a normal BMI, obesity at both early adulthood and later life was associated with 99% increase in the risk of all-cause mortality. Obesity in early and/or late adulthood was also associated with a higher risk of adverse clinical risk characteristics. Conclusion: Weight change and weight status are important predictors of mortality risk in older adults. These results highlight the importance of healthcare providers monitoring weight in older adults to detect weight loss at it is early stages, enabling more effective interventions aimed at maintaining stable weight and reducing risk of premature mortality.45 0Item Restricted The role of matrix metalloproteinase 28 and gut microbiome in the regulation of obesity and metabolic disorders(Saudi Digital Library, 2023-11) Alzahrani, Ahmad Mohammad; Pender, SylviaMatrix metalloproteinase 28 is a member of the matrix metalloproteinases family. In preliminary studies, the absence of it was found to relate to obesity. Obesity increases the risk of many health issues, including type 2 diabetes, both considered challenges to the global economy. In this study, we hypothesise that Mmp28 knock-out (KO) mice have altered metabolism influenced by the gut microbiome, and changing the living conditions will mitigate these effects. We aim to investigate whether the deletion of the Mmp28 gene is a crucial factor through which environmental management can affect the composition of gut microbiota, resulting in improved metabolism. Mmp28-KO and wild-type C57BL/6J mice were on a standard chow diet in specific pathogen-free (SPF) conditions and transferred to the conventional mouse room (CMR) for five weeks. Mice were fasted overnight and sacrificed at 30 weeks old. The livers were used for histology, and metabolic indicators were analysed using RT-qPCR and biochemical assays, while the faecal samples were used for microbiome analysis using 16s rRNA sequencing. When housed in SPF, Mmp28-KO mice had dyslipidaemia and fatty livers in addition to increased body weights and insulin resistance. They also had lower levels of the carbohydrate-digesting bacterium Bifidobacterium and higher levels of the Firmicutes phylum and its genus, Lachnospiraceae. The five weeks transfer to CMR caused weight loss, improved insulin resistance and reduced fatty liver in the mice. There was a rise in the abundance of Oscilibacter and a decline in the quantity of Firmicutes following decreased circulating butyrate. These results suggest Mmp28 is vital in regulating body weight and metabolism via alterations to the gut microbiome. They also show a change of sanitation conditions for five weeks can rebalance the gut microbiome and reshape body metabolism and obesity in genetically susceptible individuals. There are lessons to learn and study in humans.11 0