Saudi Cultural Missions Theses & Dissertations
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Item Restricted The impact of lifestyle factors, dietary energy restriction and religious fasting on body composition, gastrointestinal hormones and markers of health(Saudi Digital Library, 2025) Alogaiel, Deema; Lobo, Dileep N; Simpson, Liz; Macdonald, Ian ABackground Intermittent fasting and dietary interventions to bring about weight-loss have received considerable attention for their potential metabolic health benefits. However, gaps still exist in understanding their effects on appetite regulation, body composition changes across different age groups, and the methodological challenges in assessing these outcomes. This thesis aimed to: 1. undertake a systematic review to examine the effect of Ramadan intermittent fasting on appetite-regulating hormones in healthy individuals (CHAPTER 3); 2. investigate relationships between lean body mass, physical activity, age, and body composition in overweight individuals with pre-diabetes (CHAPTER 4); 3. explore the impact of lifestyle factors and eating behaviours on body composition changes following an 8-week low-energy diet intervention (CHAPTER 5), and 4. validate commonly used assessment tools for dietary protein intake, body composition, and physical activity against their respective reference standards (CHAPTER 6). Methods 1. A systematic review and meta-analysis examined 16 studies (n=664 participants) to investigate the effects of Ramadan intermittent fasting on circulating leptin, ghrelin, insulin, gastrin, glucagon-like peptide-1, peptide YY, and cholecystokinin concentrations. 2. A secondary analysis of cross-sectional data from 220 overweight and obese individuals with pre-diabetes (aged 25-70 years) from the Prevention of diabetes through lifestyle Intervention and population studies in Europe and around the World (PREVIEW) diabetes risk study to explore relationships between body mass, regional body composition (measured by Dual Energy X-Ray Absorptiometry; DXA), age and physical activity (assessed using accelerometry). 3. A secondary analysis of anthropometric, metabolic, and behavioural outcomes (including eating behaviours measured through validated questionnaires) from 221 participants (91 males, 130 females) from the PREVIEW cohort, collected before and after an 8-week low-energy diet intervention (810 kcal/day). 4. Dietary protein intake, assessed via 24-hour urinary nitrogen excretion, was compared with self-reported dietary records (n=264); body composition via bioelectrical impedance was compared with data from DXA scans (n=37), and physical activity estimation via the Baecke questionnaire was compared with accelerometry-derived time spent in sedentary and moderate/vigorous activity (MVPA). Results 1. Ramadan intermittent fasting increased blood ghrelin concentration (3 studies; standardised mean difference (SMD) = 0.31 pg/mL, 95% CI: 0.03 to 0.60), but had no effect on leptin (12 studies; SMD = −0.11 μg/mL, 95% CI: −0.36 to 0.14), insulin (6 studies; SMD = −0.24 μU/mL, 95% CI: −0.54 to 0.02), or gastrin concentrations (3 studies; SMD = 0.23 pg/mL, 95% CI: −0.71 to 0.99), with high heterogeneity observed across leptin studies, suggesting varied individual responses. 2. In individuals with pre-diabetes, lean body mass and leg lean mass decreased with increasing age category in females, with males having greater lean leg mass compared with females across all age groups. Leg lean mass was positively associated with body weight, with physical activity only modifying this relationship in females, though in all participants, no association between leg lean mass and physical activity was observed. 3. The low-energy diet brought about substantial weight loss (median -11.3 kg) in participants, with males experiencing greater reductions in weight, lean mass (-4.5 vs -2.5 kg), and fat mass (-8.8 vs -7.3 kg) compared with females. Higher baseline dietary restraint scores were associated with greater weight loss success (R=0.276, P<0.001), while higher disinhibition predicted poorer outcomes (R=-0.173, P<0.05), with these behavioural influences differing between sexes. Baseline physical activity levels did not influence lean mass preservation or fat mass loss during the period of weight-loss. 4. The 8-week LED intervention resulted in improvements in metabolic parameters, including reduced fasting glucose, insulin, triglycerides, and C-peptide concentrations. Sex-specific responses were observed, with males showing greater reductions in fasting insulin (-25.7 pmol/L difference, P<0.001), C-peptide (-211 pmol/L difference, P<0.001), and triglycerides (-0.210 mmol/L difference, P<0.001) compared with females. Males also demonstrated larger improvements in insulin sensitivity indices (HOMA-IR and QUICKI) than females. 5. Validation studies revealed systematic differences between assessment methods: self-reported dietary protein intake differed from biomarker-derived estimates, with proportional bias between measures emerging during a weight maintenance intervention phase (overall R=0.394, P<0.001). Body composition assessed by BIA and DXA showed strong agreement between measurements (percentage body fat R=0.853, fat mass R=0.896, and fat-free mass R=0.841) supporting BIA as a practical alternative to DXA. Physical activity assessments demonstrated modest correlations between subjective and objective measures (R=0.320 for MVPA) reflecting the different aspects of physical activity being assessed by each tool. Conclusion Increased circulating ghrelin, reported during Ramadan fasting, may drive a stimulation of appetite. Cross-sectional analysis revealed age-related differences in lean mass, with lower lean mass observed among older participants, particularly females. This pattern underscores the importance of women maintaining physical activity as they age to preserve muscle mass. The low-energy diet intervention demonstrated efficacy in reducing body weight and improving metabolic health, with notable sex-specific responses in insulin sensitivity and lipid metabolism, alongside baseline eating behaviours serving as important predictors of weight loss success. The method validation studies provided methodological insights for future research in nutritional epidemiology and clinical practice.26 0Item Restricted Effects of Ketogenic Diets on Body Composition in Adults with Obesity and Overweight – Systematic Review of Randomized Controlled Trials(Saudi Digital Library, 2025) Alotaibi, Sultana; Brown, Adrian; Kalea, AnastasiaEffects of Ketogenic Diets on Body Composition in Adults with Obesity and Overweight – Systematic Review of Randomized Controlled Trials Abstract (250 words): Background/Objectives: Even though ketogenic diets (KD) are gaining more attention in weight management, their effects on body composition as a standalone treatment remain uncertain. The aim of this review was to evaluate the effects of KD (<50g/day of carbohydrate) as the sole intervention for over 12 weeks on body composition outcomes in adults living with overweight/obesity. Methods: Three different databases (Cochrane library, Embase, and Ovid Medline) were searched following PRISMA guidelines for randomized controlled trials (RCT’s) published in the last twenty years. Studies were included if they reported at least one of the following outcomes [fat mass (kg or %), lean mass (kg or %), fat-free mass “FFM” (kg), bone mass content (kg) or /density (g/cm2)]. Screening was performed using Rayyan website. Data were extracted and synthesized narratively exploring dietary composition heterogeneity, confirmation of ketosis, and data analyses. Risk of bias (RoB) was assessed using Cochrane RoB2 tool. Results: Eight studies met our criteria, all of them had concerns on risk of bias. Studies showed that KD had greater effects in decreasing body fat and lean mass compared to other interventions; however, these effects tend not to be significant. There were no effects on FFM and bone mass, but long-term studies were limited. Conclusions: KD appear to effectively decrease fat mass but may negatively affect lean mass especially in the short term. Future studies should aim for controlling carbohydrate and protein intake to confirm the impacts of KD on body composition in the long term.8 0Item Restricted The Effect of Green Tea Supplementation on Overweight and Obese Women of Reproductive Age (18–50 Years): A Systematic Review(Saudi Digital Library, 2025) Almutairi, Omar; Sue, Azam-AliBackground: Overweight and obesity among women of reproductive age pose substantial health risks. Green tea (GT), rich in catechins such as epigallocatechin-3- gallate, has been proposed as an adjunct to lifestyle interventions for weight management. However, evidence across studies, mainly due to variability in dose, formulation and co-interventions, remains inconclusive. Objective: This systematic review aimed to evaluate the impact of GT supplementation on anthropometric and metabolic outcomes in women of reproductive age 18–50 years who suffer from overweight/obesity. Methodology: A systematic search (2010 onwards) of PubMed and MEDLINE (Ovid) identified 663 records; after removing 286 duplicates, 377 titles/abstracts were screened and 50 full texts assessed. Seven randomised controlled trials (RCTs) met the inclusion criteria (women 18–50 years, BMI ≥ 25 kg/m²; GT tablets/capsules/powder; 4–12 weeks). The primary outcomes were changes in body weight, body mass index (BMI) and waist circumference (WC); secondary outcomes included lipid profile, blood pressure and fasting blood glucose. Risk of bias (RoB) was assessed using the Cochrane RoB 2 tool. Results: Across the seven RCTs (n = 255), GT supplementation was associated with modest reductions in body weight (−1.8 to −5.7 kg) and BMI (−0.7 to −1.8 kg/m²), with some evidence of decreases in WC. Effects were most pronounced when supplementation was combined with structured exercise. Trials prescribing isocaloric, energy-restricted diets to both groups often showed minimal between-group differences, underscoring the primacy of energy deficit. Effects on triglycerides and low-density lipoprotein were heterogeneous and often aligned with training rather than GT itself; fasting glucose generally showed no meaningful between-group differences. Conclusion: GT supplementation appears to provide small but potentially meaningful benefits for weight management in overweight and obese women of reproductive age, particularly when combined with exercise. However, heterogeneity in dose, intervention design and study quality limits definitive conclusions. Larger, longer-term RCTs are required to determine whether these short-term benefits translate into sustained improvements in anthropometric and cardiometabolic health.10 0Item Restricted The effect of obesity surgery on taste, brain function and structure(Saudi Digital Library, 2025) Alalsheikh, Alhanouf; Goldstone, Tony; anderMiras, Alex.88 0Item Restricted The Role of Nerve Growth Factor in Diabetic Cardiomyopathy(Auburn University, 2025) Jafari, Hassan Ali; Jeganathan, RameshObesity and type 2 diabetes mellitus (T2DM) are characterized by increased levels of circulating fatty acids, resulting in metabolic abnormalities in the heart. Emerging data has demonstrated that cardiac dysfunction, including diabetic cardiomyopathy (DCM), is linked to obesity and T2DM. Nerve growth factor (NGF), a neurotrophic factor, plays pro-survival and anti-apoptotic roles in cardiomyocytes. Therefore, the first study aimed to investigate the effects of NGF on myocardial insulin resistance, oxidative stress, apoptosis, and inflammation. In vitro study using H9c2 cell lines showed that high-glucose treatment induced myocardial insulin resistance. Combining palmitic acid and high-glucose treatment increased oxidative stress and activated apoptotic and inflammatory markers in cardiomyocytes. We also found that NGF administration prevented diabetic cardiomyopathy by inhibiting myocardial insulin resistance, oxidative stress, cardiac apoptosis, and inflammation via activation of the PI3K/Akt. The second part of the dissertation work aimed to clarify the role of mitochondrial dysfunction in the development of DCM and to examine the effects of NGF on mitochondrial dynamics, biogenesis, and mitophagy in obese and T2DM mouse models. Our western blot results showed no significant differences in mitochondrial dynamics and biogenesis proteins in all groups. However, cardiac mitophagy was suppressed in diabetic mice. Notably, intranasal NGF administration showed no effects on mitochondrial function. In summary, NGF administration prevented obesity- and T2DM-induced diabetic cardiomyopathy in vitro but not in vivo. These results suggest that the cardioprotective effects of NGF may depend on the delivery route of NGF. Further research is needed to clarify its effectiveness in diabetic heart using different NGF delivery routes.32 0Item Restricted The Effectiveness of School-Based Nurse Intervention in Managing Obesity among Students Aged 6-18 years old(University of Glasgow, 2024-07-29) Almuqeet, Balssam; Rosemary, MullenAbstract Background: Schools play a crucial role in shaping healthy lifestyles; however, school nurses are often excluded from obesity intervention programs. In 2022, 390 million children aged 5-19 were overweight and 160 million were obese, therefore effective methods of intervention are more important than ever. Aims: This review aims to explore the effectiveness of school-based nurse interventions in managing obesity among school-aged students from 6-18 years old. Methods: A comprehensive literature search of Medline Ovid, CINAHL, Cochrane library, and PubMed databases identified randomised controlled trials and quasi experimental studies from the last ten years. The inclusion criteria included school students aged from 6-18 years, interventions delivered by nurses in school, and reported outcome measures on weight or BMI. Studies that were not experimental designs were excluded. Joanna Briggs critical appraisal tools were used to appraise methodological quality. Results: Seven studies met the eligibility criteria. Interventions delivered by school nurses included educational sessions, physical activity programs, and dietary guidance. The measurable outcomes included improvements in dietary behaviour, decreases in BMI, and increases in physical activity levels among students. None of the studies used blinding, some studies did not clearly report the attrition rate. Despite these limitations, all studies used appropriate study designs and applied rigorous statistical analyses. Six out of seven studies reported significant improvement in dietary habits, five studies found an increase in physical activity levels among the students, and four studies observed a decrease in BMI. Conclusions: The findings of the review suggest that school-based nurse interventions are effective in managing obesity among school students. Future research should include objective measures and use longitudinal designs to assess the sustainability and impact on BMI.47 0Item Restricted Knowledge, perception, and experience with Ketogenic Diet for the treatment of overweight and obesity among adults: a systematic review(University Of Sheffield, 2024-07-30) Alghamdi, Ghaday; Akparibo, RobertBackground: during the past decades, the prevalence of obesity has significantly increased around the globe, leading to increased demand for dietary interventions for weight reduction. Among these, ketogenic diet (KD) has gained great attention among adults and has been proposed as a promising option to achieve significant weight loss in a short period of time. Aim: to evaluate and critically appraise the current observational data exploring knowledge, perception, and experience of individuals using KD for weight loss, including their adherence to the diet. Methods: relevant studies were identified through five electronic databases: Web of Science, Medline via Ovid, CINAHL, Scopus, and PsycInfo, which sufficiently covered all key disciplines for the review. Eligible studies included observational studies published from 2020 to 2024, in English language, and exploring adults’ knowledge, perception, and experience with KD to manage their weight. Quality of the included studies was assessed using the AXIS appraisal tool for cross-sectional studies (CSSs). A narrative synthesis was carried out to summaries and interpret the results. Results: five studies were included in the review. The quality of studies varied: three studies were of high quality, one was of moderate quality, and one was of low quality. All of the five studies assessed adults’ knowledge and perception of KD for weight management, and three explored their current/ previous experience with the diet. In general, the overall knowledge level of participants was “good” except for one study that reported inadequate level of knowledge. The majority of participants agreed that KD is a popular weight loss intervention but argued about how safe and easy it is to be followed in the long term and that it should always be followed under medical supervision. Participants’ experience with KD showed effective weight loss outcomes with slight variations in adherence duration. The minimum duration for following KD was less than a month, and the maximum duration was six months, leading to weight regain among some participants. Conclusions: the findings conclude that KD has been an effective weight loss strategy if followed under medical supervision. However, adherence level to the diet was low, which increased the chance of weight regain. Future research: robust studies are required to evaluate KD’s potential long-term health implications, as well as assess KD effectiveness for the treatment of overweight and obesity including its sustainability.25 0Item Restricted Knowledge, perception, and experience with Ketogenic Diet for the treatment of overweight and obesity among adults: a systematic review(University Of Sheffield, 2024-05-08) Alghamdi, Ghaday; Akparibo, RobertBackground: during the past decades, the prevalence of obesity has significantly increased around the globe, leading to increased demand for dietary interventions for weight reduction. Among these, ketogenic diet (KD) has gained great attention among adults and has been proposed as a promising option to achieve significant weight loss in a short period of time. Aim: to evaluate and critically appraise the current observational data exploring knowledge, perception, and experience of individuals using KD for weight loss, including their adherence to the diet. Methods: relevant studies were identified through five electronic databases: Web of Science, Medline via Ovid, CINAHL, Scopus, and PsycInfo, which sufficiently covered all key disciplines for the review. Eligible studies included observational studies published from 2020 to 2024, in English language, and exploring adults’ knowledge, perception, and experience with KD to manage their weight. Quality of the included studies was assessed using the AXIS appraisal tool for cross-sectional studies (CSSs). A narrative synthesis was carried out to summaries and interpret the results. Results: five studies were included in the review. The quality of studies varied: three studies were of high quality, one was of moderate quality, and one was of low quality. All of the five studies assessed adults’ knowledge and perception of KD for weight management, and three explored their current/ previous experience with the diet. In general, the overall knowledge level of participants was “good” except for one study that reported inadequate level of knowledge. The majority of participants agreed that KD is a popular weight loss intervention but argued about how safe and easy it is to be followed in the long term and that it should always be followed under medical supervision. Participants’ experience with KD showed effective weight loss outcomes with slight variations in adherence duration. The minimum duration for following KD was less than a month, and the maximum duration was six months, leading to weight regain among some participants. Conclusions: the findings conclude that KD has been an effective weight loss strategy if followed under medical supervision. However, adherence level to the diet was low, which increased the chance of weight regain. Future research: robust studies are required to evaluate KD’s potential long-term health implications, as well as assess KD effectiveness for the treatment of overweight and obesity including its sustainability.4 0Item Restricted Attenuated growth during early postnatal life protects offspring from obesity and a fatty liver.(The University of Aberdeen, 2024-07-23) Hasaballah, Khulod; Kolb, AndreasEarly life nutrition significantly impacts adult metabolic health, particularly protein supply during pregnancy and lactation, affecting susceptibility to metabolic syndromes like obesity, type II diabetes, fatty liver, and cardiovascular disease. This thesis used a mouse model of delayed postnatal growth to evaluate the impact of early nutrition on adult metabolic health. Programmed mice nursed by a casein-deficient mother only grow to 50% of their body weight by the end of lactation. During adolescence, the programmed mice reach about 80% of the weight of control animals but then retain that lower weight throughout life. The reduced postnatal growth results in a partial resistance to high-fat diet-induced obesity and full protection against fatty liver. Chapter 3 found that programmed mice increased the expression of energy expenditure markers Dio2 and PGC1a in brown adipose tissue at a conventional house temperature of 20 °C. They also showed increased UCP1 expression and adiponectin expression. In a second experiment, at a thermal house temperature of 30 °C, PGC1a expression increased in brown adipose tissue, subcutaneous white adipose tissue, and epididymal white adipose tissue. Ucp1 gene expression was also increased in BAT and sWAT, with a reduction in response to a high-fat diet. Programed mice showed increased adiponectin expression and decreased leptin expression. chapter 4 found that a microarray study found that early nutrition significantly impacted the expression of FGF21, Elovl5, Insig2, and Erg1 in programmed mice, which is associated with lipid metabolism and metabolic health. This difference was observed in programmed mice compared to wild-type mice. Quantitative PCR confirmed the findings, suggesting protection against obesity and fatty liver. In chapter 5 found that in vitro experiments using HepG2 liver cells demonstrated that the casein amino acid composition enhances lipid storage in liver cells compared to other amino acid compositions such as soy, microalgae, and cell culture medium.23 0Item Restricted Anticipation of the Positive Effect of Changing Food Markting in Saudi Arabia(Bournemoith University, 2023-09-06) Harith, Wallaa; Hartwell, HeatherThe hospitality sector contributes significantly to the community health. The food environment in retailers, restaurants and coffee shops can shape individuals' eating habits. Thus, the Saudi Food and Drug Ministry considers transforming food environment in the country in order to boost health. Nevertheless, Saudi Arabia has a high number of noncommunicable diseases attributed mostly to less healthy eating habits. In actual fact, interventions in grocery retailer outlets, becomes a popular strategy to nudge healthier purchasing. Product placement, for instance, is one of the most popular forms of retail intervention used to stimulate consumers to make healthier decisions, thereby reducing the numbers of obesity and its complications as it has reached an epidemic stage in Saudi Arabia. This dissertation, therefore, analyses the association between product placement of food in retail outlets and dietary behaviour and purchasing of these products. This study applies a semi-structured interview approach in light of the lack of existing publications addressing the impact of product placement on people dietary habits and health outcomes specifically in my geographical location. The findings indicate that food environment in retail outlets significantly impacts consumers' choices. This study has found that the product placement technique positively promotes and increases healthy food consumption which subsequently boosts health; it also stimulates costumers to buy products deemed to be healthy. Several motivations, including the placing, price, appearance and promotion, may encourage consumers to buy the food product.33 0