Saudi Cultural Missions Theses & Dissertations
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Item Restricted Associations Between Living Arrangements, Changes in Lifestyle and Anthropometric Traits During the First Year of University(Saudi Digital Library, 2026) Alharbi, Ferdous; Speakman, John; Hambly, CatherineIntroduction: The transition into university is often accompanied by lifestyle changes that can influence weight and health behaviours, with evidence highlighting increased risk of weight gain during the first academic year. While the “Freshman 15” theory, coined in the United States of America (USA), has been widely discussed, referring to an average weight gain of around 6.8 kg (15 lb) during the first year of university, findings remain inconsistent, and less is known about how different living arrangements may shape these changes. This thesis examines the associations between living arrangements, lifestyle behaviours, and anthropometric changes among first-year university students, and compares these with patterns observed in non-university peers. Methods: Two longitudinal observational studies were conducted. Study 1 followed 78 participants at baseline, three, and eight months after entering University (across one academic year), including those living at home, in private accommodation, in halls of residence (University accommodation), and non-university peers. Study 2 tracked 40 of these participants in halls, private accommodation, and at home as they transitioned to the second year. Anthropometric traits (body weight (BW), body mass index (BMI), body fat percentage (BF%), waist-to-hip ratio (WHR), and weight-for-age percentile (W/A)) were recorded. In addition, lifestyle behaviours (diet, physical activity, sleep, and stress) were assessed using questionnaires, complemented by objective assessments from the ActiGraph GT9X Link accelerometer (physical activity and sleep). Dietary intake was assessed via Intake24’s online 24-hour dietary recall tool and reassessed after excluding misreported records. Results: Most changes in weight, body composition and lifestyle behaviours occurred within groups across the academic year, with students living away from home showing the largest increases in weight, BMI and WHR. Although between-group differences were generally limited, living arrangements influenced the timing and magnitude of changes in diet, physical activity, sleep and stress, and WHR remained consistently higher among students in halls compared with those living at home or in private accommodation. Non-university participants also experienced behavioural and BF% changes, indicating that many challenges were not exclusive to university students. In the follow-up study after one year at university, similar within-group patterns persisted, suggesting that early behavioural and anthropometric changes tended to continue over time. Students who started university in halls and in private accommodation showed further increases in weight and BMI across the 12-month follow-up, while those living at home remained comparatively stable. Conclusions: These findings demonstrate that early lifestyle and body composition changes among young adults are shaped more by within-group patterns than by large differences between accommodation types. By integrating self-reported and objective measures across two longitudinal studies, this thesis provides clearer evidence on how diet, physical activity, sleep and stress evolve from university entry through the first full academic year and after one year at university. The thesis directly addressed its research objectives and answered all research questions by identifying when behavioural and anthropometric changes occur, which groups are most affected, and how living arrangements influence these trajectories over time. The results highlight areas that may benefit from future preventive efforts to support students’ health during the transition into university, such as improving food environments in halls, supporting affordable healthy eating for students living away from home, expanding access to physical activity opportunities, strengthening stress-management and sleep-support resources during this life stage.25 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 Benefits of Supplementation with LCn-3 PUFA during Diet-Induced Body Mass Loss and Maintenance Phases on Body Composition, Muscle Function, and Appetite(University Of Glasgow, 2025) Alblaji, Mansour Ghazi; Malkova, Dalia; Gray, StuartObesity is a complex medical condition that is associated with a range of comorbidities, including hypertension, type 2 diabetes, dyslipidaemia, gastrointestinal disorders, joint pain, and musculoskeletal complications. Current treatment approaches for obesity primarily involve lifestyle modifications, including diet-induced weight loss and physical exercise. However, evidence from previous research highlights a concern regarding diet-induced body mass loss: approximately 25–30% of the total body mass lost is derived from fat-free mass (FFM). This decline in FFM is associated with diminished muscle mass and function, reduced metabolic rate, and an elevated risk of body mass regain. Attenuating FFM loss during body mass loss is therefore critical for healthy body mass loss. Long-chain n-3 polyunsaturated fatty acids (LCn-3 PUFA) have been proposed as a potential strategy to mitigate these effects by influencing body composition, muscle mass and function, and inflammation during energy balance. Evidence suggests that LCn-3 PUFA can reduce fat mass while enhancing FFM, improving muscle mass, strength, and function, and mitigating inflammation. However, despite these potential benefits, the evidence supporting the efficacy of LCn-3 PUFA supplementation during diet-induced body mass loss on body composition, muscle function, and inflammatory markers remains limited and requires further exploration. The first aim of this thesis was to systematically investigate the effects of supplementation with LCn-3 PUFA during caloric restriction (CR) on body mass, fat mass and FFM loss (Chapter 2). Eleven studies were included in this systematic review and meta-analysis as they met the inclusion criteria of the systematic review, with a total of 637 participants. The participants’ age ranged between 18 and 61 years, with a mean BMI ranging between 27 and 36 kg/m2 . Pooled analyses showed that LCn-3 PUFA supplementation during CR had no additional effect on changes in body mass (SMD = -0.05: 95% CI -0.22 to 0.13; p = 0.62; I2 : 10%), BMI (SMD = -0.06, 95% CI -0.25 to 0.13; p = 0.55; I2 : 18%), fat mass (SMD = - 0.01; 95% CI -0.25 to 0.24; p = 0.96; I2 : 46%), or FFM (SMD = 0.12, 95%CI -0.14 to 0.37, p = 0.36; I2 :35%). The lack of impact of LCn-3 PUFA on body mass and composition observed in this systematic review (Chapter 2) may be attributed to some limitations in the iii included studies. Most of the studies assessed body composition using bioelectrical impedance analysis (BIA), applied low doses of LCn-3 PUFA, and also did not evaluate muscle strength during diet-induced body mass loss. To address the gaps identified in our systematic review, a double-blind, randomised, placebo-controlled trial (RCT) was conducted, including a 4-week preparation phase, an 8-week alternate-day fasting (ADF) phase, and an 8-week body mass maintenance phase, with participants taking 4 capsules/day of krill oil as a source of LCn-3 PUFA throughout (Chapter 4). Body composition was evaluated via the deuterium water (D2O) dilution method, and parameters of muscle function, and fasting blood samples were measured at the pre- and post body mass loss phase. Forty-one healthy adults completed this RCT. The two-way ANOVA revealed significant time and time*group interaction effects on FFM, handgrip strength, chair rising test, TNF-α, CRP, and systolic blood pressure (all p < 0.05). Post-intervention, there was a small, non-significant reduction in FFM (- 0.2 ± 0.9 kg, p > 0.05) and handgrip strength (-0.2 ± 0.5 kg, p > 0.05) in the krill oil group, whereas the placebo group experienced significant reductions in FFM (- 1.2 ± 2.0 kg, p < 0.05) and handgrip strength (-0.9 ± 0.7 kg, p < 0.05). The time to conduct the chair rising test decreased significantly in the krill oil group (-1.8 ± 0.9 s, p < 0.05), whereas the reduction in the placebo group was not significant (- 0.3 ± 1.2 s, p > 0.05). TNF-α levels decreased significantly in both groups (all p < 0.05), with a greater reduction in the krill oil group (-1.4 ± 0.2 pg/ml) compared to the placebo group (-0.9 ± 0.5 pg/ml). Similarly, CRP levels were significantly reduced in both groups (all p < 0.05), with a greater reduction in the krill oil group (-51.4 ± 25 ng/ml) than in the placebo group (-33.5 ± 12.6 ng/ml). Systolic blood pressure decreased significantly in both groups (all p < 0.05), with a greater reduction observed in the krill oil group (-9 ± 6 mmHg) compared to the placebo group (-4 ± 4 mmHg). No significant difference was observed in changes between groups in body mass, body fat, insulin, glucose HOMA-IR, TAG, or diastolic blood pressure (all p > 0.05). Therefore, from this RCT, it was concluded that supplementation with krill oil during diet-induced body mass loss via ADF helps to attenuate the associated decline of FFM and muscle function, improve functional capacity, and reduce TNF-α and CRP levels. Supplementation with LCn-3 PUFA, in the absence of CR, has been associated with appetite reduction and enhanced sensations of fullness and satiety in individuals iv living with overweight or obesity. However, the effects of LCn-3 PUFA supplementation during diet-induced body mass loss on appetite and gastrointestinal appetite hormones remain underexplored. In Chapter 5, the impact of LCn-3 PUFA during diet-induced body mass loss on changes in appetite and gastrointestinal appetite hormones was examined in a subset of the participants of the RCT (Chapter 4). This exploratory study included 28 adults (mean age: 39.4 ± 11.7 years; BMI: 27.9 ± 3.2 kg/m²) who participated in the RCT (Chapter 4). Body mass, body fat, and FFM were measured at baseline (week 4), at the end of the body mass loss phase (week 12), and at the end of the body mass maintenance phase (week 20). Fasting and postprandial subjective appetite scores, along with plasma concentrations of acylated ghrelin, Glucagon-Like Peptide-1 (GLP-1), and Peptide YY (PYY), were assessed before and after the body mass loss phase. The ANOVA revealed a significant time (p<0.05), but not group (p>0.05) or time*group interaction (p>0.05) effects for body mass, fat mass or FFM during the body mass loss phase. During the maintenance phase, no significant (p>0.05) time, group, or time*group interaction effects were found for body mass and FFM, but for fat mass, a significant time*group interaction effect was observed (p<0.05). During the maintenance phase, in the krill oil group, fat mass remained unchanged (p>0.05) but increased significantly (p< 0.05) in the placebo group. This coincided with the body mass loss-induced significant reduction (p<0.05) in the composite appetite score (CAS) in the krill oil but not the placebo group (p> 0.05). There was no significant (p>0.05) time, group, or time*group interaction effects for acylated ghrelin, GLP-1, and PYY during the body mass loss phase. Changes in body mass during the body mass loss and body mass maintenance phases were not correlated with acylated ghrelin, PYY, or GLP-1 (all p > 0.05). Body mass changes during the body mass loss phase showed a tendency toward a significant positive correlation with changes in CAS (r=0.36, p = 0.06). Therefore, krill oil supplementation during body mass maintenance may induce favourable changes in subjective appetite and prevent short-term fat mass regain. Overall, the current thesis demonstrates that supplementing with LCn-3 PUFA during diet-induced body mass loss is a promising strategy to attenuate the loss of FFM and muscle function. Beyond these benefits, LCn-3 PUFA supplementation also reduces inflammation and lowers blood pressure, underscoring its potential to enhance body composition, preserve muscle mass, and promote overall well- v being during body mass loss. Furthermore, LCn-3 PUFA supplementation may reduce subjective appetite and might help to prevent fat mass regain during the body mass maintenance phase, further supporting its role in long-term body mass management.22 0Item Restricted Body Composition among Healthy Controls: Association with Eating Disorder Symptoms and Muscular Function(University College London, 2024-08-12) Abumunaser, Albatool; Robinson, PaulBackground and Aim: Despite its widespread use, the Body Mass Index (BMI) has significant limitations as a nutritional status indicator. This study aims to advocate for including complementary parameters like body composition (BC) and muscle strength tests for a thorough nutritional assessment. It also explores BC associations with disordered eating behaviour and muscle strength. Methods: The study included 33 participants aged 20-53 from University College London (UCL) or their acquaintances. Participants completed online demographic and Eating Disorder Examination questionnaires (EDE-Q). BC was assessed using a Bioelectrical Impedance Analysis (BIA) device, and muscle strength was measured using mid-upper arm circumference (MUAC), handgrip strength (HGS), and Sit-Up Squat-Stand (SUSS). Results: The median EDE-Q global score was 0.66 [0-4.01], with 30.30% engaging in shape or weight-influencing behaviours. Males scored significantly higher in the restraint subscale (P <0.01). Gender differences were observed in all BIA parameters except fat mass (FM).19.23% of females were classified as low HGS. Significant associations were found between EDE-Q global score and BMI (P < 0.01), FM Index (FMI) (P < 0.05), and MUAC (P < 0.05). Both BMI (β = -0.657, p = 0.001) and Fat-Free Mass Index (FFMI) (β = 0.983, p < 0.001) were significant predictors of HGS. BMI (β = 10.19, p = 0.77) became insignificant for MUAC when FMI and FFMI were included. No significant differences in FFM across BMI categories, but significance was observed in FM between normal weight and both overweight/obese categories (P <0.001). Discussion: This study emphasises the need to supplement BMI with additional measurements and the insights BIA and muscle function parameters provide. It recommends incorporating parameters reflecting nutritional and hydration status within eating disorder (ED) assessments. These measurements should be adopted to improve nutritional assessment in ED settings.1 0