Introduction: Childhood obesity is associated with increased physical and psychosocial co-morbidities, and with lower cognitive function and educational attainment. Clinical guidelines recommend lifestyle interventions (healthy diet, increased physical activity and decreased sedentary behaviour) for the treatment of childhood obesity. Lifestyle interventions are known to benefit cognitive function and educational attainment in normal weight children. However, it is not known whether the same benefits occur when lifestyle interventions are used to treat overweight and obese children. Aim & Objectives: The aim of this thesis was to assess the effect of lifestyle interventions on educational attainment in overweight and obese children in three studies: Objective 1: Assess the efficacy of lifestyle interventions for improving educational attainment. Objective 2: Establish the feasibility of assessing the effectiveness of a childhood primary care weight management programme on educational attainment. Objective 3: Investigate the potential mechanisms for how lifestyle interventions for weight management might benefit educational attainment of overweight children. Methods: Study 1: Systematic (Cochrane) review and meta-analysis of randomised controlled trials of single or multicomponent lifestyle interventions in children aged 3-18 years. Study 2: Quasi-experimental study linking childhood weight management data of children 5-15 years with education data from local education authorities in Scotland. Study 3: Qualitative study designed to gain insight into overweight and obese children’s and their parents’ perceptions and experiences in school and weight management programme obtained from focus groups and interviews. Results: Study 1: The systematic review included six studies of 674 overweight and obese children and adolescents. Findings indicated that school-based healthy lifestyle education combined with nutrition interventions can produce small improvements in overall school attainment. Single component physical activity interventions produced small improvements in mathematics attainment and associated cognitive skills (executive function, and working memory). There was no evidence of an effect of any lifestyle intervention on reading, vocabulary and language attainment, attention, inhibitory control, and simultaneous processing. Study 2: Cross-sectorial administrative data-linkage was shown to be feasible. This pilot study showed no evidence of a beneficial effect of a primary care child weight management programme on reading, writing and mathematics attainment in overweight and obese children. However, a definitive study to properly assess the effectiveness of lifestyle interventions outside the research environment is clearly feasible in Scotland. Study 3: The themes emerging from focus groups and interviews were body weight related school experiences, attitudes towards school, obesity and school performance, and influence of weight management. Participants perceived that being overweight can benefit educational attainment because a lack of friends means they are less distracted from learning. Low psychosocial well-being experienced by the participants was improved after taking part in a weight management programme. Parents understood this benefit could potentially impact positively on school experiences and attainment in the long-term. Conclusion: Given the high prevalence of childhood obesity, educational and cognitive outcomes could be improved, to some extent, in a very large number of school-aged children through increased physical activity and nutrition education intended for weight management. Health policy makers should be aware of these potential additional benefits when promoting physical activity and healthy eating in schools. Childhood weight management programmes exist widely and thus provide an opportunity to evaluate their impact on educational outcomes in the community. Implemented child weight management programmes may benefit from improved recording of routine data and from obtaining participants’ administrative education data to ensure adequate support and supervision of this vulnerable population. In addition, weight management programmes could consider promoting psychosocial well-being of participants to potentially benefit both health and educational outcome. Lifestyle interventions for obese children and adolescents are under-investigated particularly with regard to a) efficacy in clinical and community settings, b) short and long-term effectiveness for improving educational attainment and c) mechanisms of benefit on educational attainment and cognitive function.

Three studies were designed to investigate the effects of exercise-based lifestyle interventions including diet change and exercise training on cardiovascular and autonomic responses to various physical and mental challenges in untrained premenopausal women. In Study 1, the effects of different tasks designed to activate the sympathetic nervous system on autonomic control of cardiovascular functioning such as the Stroop colour-word task (Stroop) and lower body negative pressure (LBNP) in 20 untrained premenopausal women (22.6??0.7 years) were determined. In Study 2, a longitudinal exercise intervention strategy was used with 18 untrained premenopausal women (22.5??0.7 years) in order to investigate the effect of 15 weeks of high intensity intermittent exercise (HIIE) training on cardiac autonomic responses to mental challenge (Stroop) and LBNP. In Study 3, the effects of HIIE training combined with a Mediterranean-style eating plan and fish oil supplement (Fish oil, Exercise, Mediterranean diet; FEM) on cardiovascular function during mental challenge (Stroop) and physical tasks (handgrip and reactive hyperaemia) were examined in 32 overweight untrained premenopausal women (22.0??0.6 years). In these studies, forearm blood flow (FBF) was assessed using Hokanson Plethysmography with the venous occlusion technique. The surface electrocardiogram and continuous beat-to-beat arterial blood pressure were also monitored. Peak oxygen uptake was assessed using open-circuit spirometry (True Max 2400, ParvoMedics). In addition, body composition was measured using DEXA (dual energy X-ray absorptiometry; DPX-IQ, Lunar Radiation). Results from Study 1 indicate that FBF response to mental challenge in young females was smaller compared to previously obtained data from age-matched males. Furthermore, this FBF response to mental challenge was negatively correlated to insulin resistance estimated by the homeostasis model assessment (HOMA-IR) (r = - .52, p < .05). In addition, when cardiopulmonary baroreceptors were unloaded by a mild level of LBNP (-20 mmHg) during Stoop, FBF response to mental challenge (vasodilation) was abolished suggesting a large dependency of vasodilation response during mental challenge on cardiopulmonary baroreflex. After 15 weeks of supervised HIIE training, aerobic fitness improved (p < .05) whereas percent of body fat was significantly decreased (p < .05). In addition, recovery BP following Stroop was significantly reduced. Insulin resistance (HOMA-IR) was marginally decreased (p = .056). Women who had higher insulin resistance (HOMA-IR) lost less fat than women with lower HOMA-IR (r = .60, p = .088). In addition, change in FBF during Stroop after training was directly related to pretest insulin resistance levels (r = .68, p < .05). Therefore, HIIE training had a normalising effect on FBF response to mental challenge. PEP/LVET ratio at rest and during LBNP was also significantly increased in women with higher HOMA-IR suggesting a reduction in cardiac contractility via a decrease in sympathetic stimulation (r = .62, p = .076, r = .62, p = .75 respectively). In Study 3 results indicated that 12 weeks of the FEM trial significantly reduced percent of body fat (p < .001), fasting insulin (p < .05), interleukin-6 (p < .05) and cortisol (p < .05), and significantly improved aerobic fitness ( ; p < .001). With respect to cardiovascular and cardiac autonomic measures, rate pressure product (RPP) was significantly reduced at rest (p < .05) and during recovery after Stoop (p < .05), suggesting decreased myocardial oxygen consumption. In addition, baseline heart rate determined in the sitting position was significantly reduced (p < .05), while both baseline high frequency power (HF) determined in supine (p < .01) and cardiac baroreflex sensitivity (BRS) determined in the sitting position (p < .05) were increased after the FEM trial. In addition, BRS determined during mental challenge also marginally increased (p = .051). In summary, lifestyle intervention including HIIE training, Mediterranean-style eating plan, and a fish oil supplement significantly enhanced parasympathetic influence of the heart and improved fitness, blood profiles, and body composition.

Three studies were designed to investigate the effects of exercise-based lifestyle interventions including diet change and exercise training on cardiovascular and autonomic responses to various physical and mental challenges in untrained premenopausal women. In Study 1, the effects of different tasks designed to activate the sympathetic nervous system on autonomic control of cardiovascular functioning such as the Stroop colour-word task (Stroop) and lower body negative pressure (LBNP) in 20 untrained premenopausal women (22.6??0.7 years) were determined. In Study 2, a longitudinal exercise intervention strategy was used with 18 untrained premenopausal women (22.5??0.7 years) in order to investigate the effect of 15 weeks of high intensity intermittent exercise (HIIE) training on cardiac autonomic responses to mental challenge (Stroop) and LBNP. In Study 3, the effects of HIIE training combined with a Mediterranean-style eating plan and fish oil supplement (Fish oil, Exercise, Mediterranean diet; FEM) on cardiovascular function during mental challenge (Stroop) and physical tasks (handgrip and reactive hyperaemia) were examined in 32 overweight untrained premenopausal women (22.0??0.6 years). In these studies, forearm blood flow (FBF) was assessed using Hokanson Plethysmography with the venous occlusion technique. The surface electrocardiogram and continuous beat-to-beat arterial blood pressure were also monitored. Peak oxygen uptake was assessed using open-circuit spirometry (True Max 2400, ParvoMedics). In addition, body composition was measured using DEXA (dual energy X-ray absorptiometry; DPX-IQ, Lunar Radiation). Results from Study 1 indicate that FBF response to mental challenge in young females was smaller compared to previously obtained data from age-matched males. Furthermore, this FBF response to mental challenge was negatively correlated to insulin resistance estimated by the homeostasis model assessment (HOMA-IR) (r = - .52, p < .05). In addition, when cardiopulmonary baroreceptors were unloaded by a mild level of LBNP (-20 mmHg) during Stoop, FBF response to mental challenge (vasodilation) was abolished suggesting a large dependency of vasodilation response during mental challenge on cardiopulmonary baroreflex. After 15 weeks of supervised HIIE training, aerobic fitness improved (p < .05) whereas percent of body fat was significantly decreased (p < .05). In addition, recovery BP following Stroop was significantly reduced. Insulin resistance (HOMA-IR) was marginally decreased (p = .056). Women who had higher insulin resistance (HOMA-IR) lost less fat than women with lower HOMA-IR (r = .60, p = .088). In addition, change in FBF during Stroop after training was directly related to pretest insulin resistance levels (r = .68, p < .05). Therefore, HIIE training had a normalising effect on FBF response to mental challenge. PEP/LVET ratio at rest and during LBNP was also significantly increased in women with higher HOMA-IR suggesting a reduction in cardiac contractility via a decrease in sympathetic stimulation (r = .62, p = .076, r = .62, p = .75 respectively). In Study 3 results indicated that 12 weeks of the FEM trial significantly reduced percent of body fat (p < .001), fasting insulin (p < .05), interleukin-6 (p < .05) and cortisol (p < .05), and significantly improved aerobic fitness ( ; p < .001). With respect to cardiovascular and cardiac autonomic measures, rate pressure product (RPP) was significantly reduced at rest (p < .05) and during recovery after Stoop (p < .05), suggesting decreased myocardial oxygen consumption. In addition, baseline heart rate determined in the sitting position was significantly reduced (p < .05), while both baseline high frequency power (HF) determined in supine (p < .01) and cardiac baroreflex sensitivity (BRS) determined in the sitting position (p < .05) were increased after the FEM trial. In addition, BRS determined during mental challenge also marginally increased (p = .051). In summary, lifestyle intervention including HIIE training, Mediterranean-style eating plan, and a fish oil supplement significantly enhanced parasympathetic influence of the heart and improved fitness, blood profiles, and body composition.

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Cluster randomized controlled trials are increasingly used to assess the effectiveness of life-style interventions in improvement of health services or prevention of disease. However, statistical methods in the analysis of cluster randomized controlled trials are not well established especially for analyzing binary outcomes. This project is motivated by the Community Hypertension Assessment Trial (CHAT) to assess the effectiveness of a 12-month community-based blood pressure management program in improving the management and monitoring of high blood pressure (BP) among older people. The study is a paired cluster randomized controlled trial, where the family physicians' practices are the clusters randomly allocated to CHAT intervention or usual practice, and a random sample of 55 patients 65 years and older were selected from the 14 practices in each study arm for health record review. The primary outcome was controlled BP over 12 months defined as systolic BP c:; 140 and diastolic BP c:; 90 for patients without diabetes or target organ damage or systolic BP c:; 130 and diastolic BP c:; 80 for patients with diabetes or target organ damage. Secondary outcomes include frequency of BP monitoring and average BP over a 12 month period. The clinical objective of this project is to evaluate the effectiveness of the CHAT intervention. The statistical objective is to compare Bayesian and classical methods of analyzing cluster-randomized trials using CHAT study as an example. We compared the results of different cluster-level analysis methods: i) un-weighted regression, ii) weighted regression, iii) random-effects meta-analytic approach, and different individual-level analyses: i) standard logistic regression, ii) robust standard errors approach, iii) generalized estimating equations, iv) random-effect logistic regression, v) Bayesian random-effect regression. We find that there is no sufficient evidence in support of the effectiveness of the CHAT intervention on all outcomes. For BP control, odds ratio (95% confidence interval) is 1.14 (0.72, 1.80) from generalized estimating equations. This result remains robust under different methods. We also find that the results from different statistical methods are different. The results from cluster-level analysis methods are quite different, while the results from the individual-level analysis methods are similar. We conclude that using various methods to analyze the trial provide good sensitivity analyses to help in interpreting the results of cluster randomized trials. Extensive simulation studies comparing the statistical powers of the different methods in different situations are required. / Thesis / Master of Science (MS)

Yes / The mental health benefits of physical activity and exercise are well-documented and asylum seekers who may have poor mental health could benefit from undertaking recommended levels of physical activity or exercise. Digital mobile applications are increasingly seen as feasible to precipitate behaviour change and could be a means to encourage asylum seekers to increase their levels of physical activity and exercise. This paper reports on a study that aimed to assess the feasibility of asylum seekers using the digital animation as a tool to change behaviour and increase their physical activity and exercise levels. A feasibility study underpinned by the principles of the COM-B behaviour change model was undertaken in West Yorkshire, UK, in 2019. Thirty participants were purposively recruited and interviewed. Peer interpreters were used as necessary. Deductive thematic analysis was undertaken to analyse the data. Overall, participants were positive about the feasibility of asylum seekers using the application as a behaviour change intervention. All expressed the view that it was easy to follow and would motivate them to increase their physical activity levels. Participants identified facilitators to this as the simplicity of the key messages, the cultural neutrality of the graphics and the availability of the mobile application in different languages. Identified barriers related to the dialect and accents in the translations and the over-simplicity of the application. This study has identified that a targeted digital animation intervention could help asylum seekers change their behaviour and hence improve their health and well-being. In designing such interventions, however, researchers must strongly consider co-design from an early stage as this is an important way to ensure that the development of an intervention is fit for purpose for different groups. / University of Bradford Research Development Fund

The prevalence of obesity continues to increase despite considerable research and innovation regarding treatment and management strategies. When completed as prescribed, exercise training is associated with numerous health benefits and predictable levels of weight loss. However, under free-living conditions the benefits of exercise are less consistent, suggesting that non-adherence and/or a compensatory response in non-exercise activity thermogenesis (NEAT) may be occurring. The accurate quantification of all components of total energy expenditure (TEE), including TEE itself, was imperative to elucidate the primary research question relating to the impact of exercise on TEE. In addition, the measurement of changes in body composition and the response to prescribed exercise were assessed in methodological and pilot investigations. Following this extensive background, the primary research question relating to the effect of exercise on levels of TEE and the associated implications of such a compensatory response could be more rigorously investigated. The first study investigated the variability in isotopic equilibrium time under field conditions, and the impact of this variability on estimates of total body water (TBW) and body composition when using the deuterium dilution technique. Following the collection of a fasting baseline urine sample, 10 women and 10 men were dosed with deuterium oxide (0.05g/kg body weight). Urine samples were collected every hour for 8 hours. The samples were analysed using isotope ratio mass spectrometry and time to equilibration was determined using three commonly employed data analysis approaches. Isotopic equilibrium was reached by 50, 80 and 100% of participants at 4, 6 and 8 h, respectively. The mean group equilibration times determined using the three different plateau determination methods were 4.8 ± 1.5, 3.8 ± 0.8, and 4.9 ±1.4 h, respectively. Isotopic enrichment, TBW, and percent body fat estimates differed between early sampling times (3-5 h), but not later sampling times (5-8 h). Therefore, sampling < 6 hours post dose compared to sampling ≥ 6 hours resulted in greater relative measurement error in TBW and body composition estimates. Although differences in equilibration time were apparent between the three plateau determination approaches, sampling at 6 hours or later may decrease the likelihood of error in body composition estimates resultant from incomplete isotopic equilibration in a small proportion of individuals. In the second study, the aim was to measure the self-paced walking (SPW) speed of adults ranging in body size from normal to obese. The utility of heart rate monitors to estimate the energy cost of walking was also investigated. Twenty-nine participants (12 normal-weight, 17 overweight or obese) completed two outdoor walking tests to determine their SPW speed. A walking treadmill test with stages below, at, and above the SPW speed was completed to compare the energy expenditure estimates of the Polar S610 and WM42 heart rate monitors with that from indirect calorimetry. The average SPW speed was 1.7 ± 0.1 m*sec-1, which was equivalent to an exercise intensity of 48.6 ± 9.4 %VO2max (61.0 ± 7.1 %HRmax). There was no difference in the energy expenditure estimation between indirect calorimetry (4.7 ± 0.7 kcal*kg*-1*h-1), the S610 (4.8 ± 1.3 kcal*kg*-1*h-1) and the WM42 (4.8 ± 1.6 kcal*kg*-1*h-1). It was concluded that the heart rate monitors provided reasonable energy expenditure estimates at the group level. However considerable error was evident at the individual level, explained in part by exercise heart rate and fitness level, suggesting that an individualised calibration should be performed where possible. An additional finding from this study was that 145 to 215 minutes of SPW per week, dependent upon the level of adiposity, is required to meet the current American College of Sports Medicine (ACSM) guidelines for health of 1000 kcal*wk-1. The purpose of the third study was to establish the level of adherence to a specific exercise prescription (1500 kcal*wk-1) by objectively quantifying unsupervised exercise energy expenditure (ExEE) in a group of obese women. The 16-wk lifestyle intervention consisted of weekly meetings with research staff, combined with promotion of increased ExEE (1500 kcal*wk-1) and a decreased dietary intake (-500 kcal*d-1). Twenty-nine obese females (Body Mass Index = 36.8 ± 5.0 kg*m2, Body Fat = 49.6 ± 3.7 %) from a hospital-based lifestyle intervention were included in the analysis. ExEE was estimated and monitored weekly using heart rate monitoring. Body composition was measured before and after the intervention by dual-energy x-ray absorptiometry (DXA). Results indicated free-living adherence to the exercise prescription was modest and variable, with 14% of participants achieving the 1500 kcal*wk-1. The average weekly ExEE (768 kcal*wk-1) represented 51.2% of the total amount prescribed. ExEE was correlated with changes in body weight (r = 0.65, p < 0.001) and fat mass (r = 0.65, p = 0.0002). Achievement of a 5% weight loss target was dependent on an ExEE level of 1000 kcal*wk-1 (p &lt0.001). Exercise 'adherers' (> 000 kcal*wk-1) lost more weight (-9.9 vs. -4.1 kg), more fat mass (-6.8 vs. -3.0 kg), and more waist circumference (-9.8 vs. -5.6 cm) when compared to 'non-adherers' (< 1000 kcal*wk-1). The results suggest that the extent of supervision and monitoring influenced exercise adherence rates. The variability in adherence highlights the importance of objective monitoring of ExEE. Identification of individuals not complying with program targets may enable intervention staff to provide additional support or make individualised adjustments to the exercise prescription. The fourth study investigated issues relating to the management and interpretation of accelerometry data when the device is to be used to monitor levels of daily physical activity. Given the high between-individual variability in accelerometry output for a given walking speed, the use of a more individualised approach to the data management has been suggested. In addition, accelerometry was used to compare daily physical activity patterns between a supervised and unsupervised exercise prescription of the same dose (1500 kcal*wk-1) in overweight and obese women. Total energy expenditure, activity energy expenditure, and vector magnitude increased significantly during the intervention. Time spent in very low intensity movement decreased from baseline to the intervention (p < 0.01) in both the supervised (-18.6 min*d-1) and unsupervised (-68.5 min*d-1) group, whereas time spent in high and vigorous intensity movement increased significantly from baseline to the intervention (p < 0.05 and p < 0.0001, respectively). The increase in vigorous movement was significantly greater in the supervised group when compared to the unsupervised group (+11.5 vs. +5.4 min*d-1, p < 0.05). Time spent above three different moderate-intensity walking thresholds increased from baseline to the intervention (p < 0.0001). The threshold determination approach significantly affected the resultant outcomes (p < 0.0001) such that the standard threshold was significantly different to both group-specific and individualised approaches. Significant differences were also noted in accelerometer output between treadmill and overground walking (p < 0.0001). A positive finding of this study was that two different interventions aimed at increasing physical activity levels in a group of sedentary and obese women were successful in gaining modest increases in overall daily movement. The change observed appears to be a replacement of sedentary movement with more vigorous physical activity. Collectively, the differences observed between threshold determination approaches, as well as between treadmill and overground walking, highlight the need for standardised approaches to accelerometry data management and analysis. In addition, the findings suggest that obese women may benefit from a certain degree of exercise supervision to ensure compliance, however, strategies to encourage these women to continue with the exercise on their own without supervision are essential to making a sustainable long-term change to their lifestyles. The final study aimed to assess whether obese women compensate for structured exercise by decreasing their NEAT and thereby impeding weight loss. Thirteen participants were prescribed 1500 kcal*wk-1 of exercise through a structured walking program (4 week supervised followed by 4 weeks unsupervised). The energy expenditure of the walks was quantified using individually-calibrated Polar F4 heart rate monitors. The DLW technique was used to measure TEE. Accelerometry measures were also collected throughout and represented an alternative method of quantifying changes in total daily movement patterns resultant from an increase in energy expenditure through exercise. Compliance with the exercise program was excellent, with the average compliance being 94% over the 8-week intervention. The adoption of moderate-intensity exercise in this group of obese women resulted in a 12% decrease in TEE (p = 0.01) and a 67% decrease in NEAT (p < 0.05). No significant change was observed in resting metabolic rate from baseline to the postintervention time-point. Compensation was significantly correlated with dietary report bias (r= -0.84, p = 0.001), body image (r = 0.75, p < 0.01), and bodily pain (r = -0.65, p < 0.05). A linear regression model including dietary reporting bias and the pain score explained 78% of the variation in ΔTEE. Compensators were therefore less likely to underreport their dietary intake, less likely to be self-aware of their obese state, and more likely to be experiencing pain in their daily life. Self-reported dietary intake decreased significantly during the intervention (p = 0.01) with specific decreases noted in fat and carbohydrate intake. The consequence of compensation was evidenced by a lack of significant change in body weight, body composition, or blood lipids (p > 0.05). However, positive outcomes of the study included improvement in the SF-36 scores of general health (p < 0.05) and maintenance of exercise program adherence into the unsupervised phase of the intervention. Qualitative data collected via interview indicated that 85% of participants experienced increased energy and positive feedback from peers during the intervention. This study confirms that exercise prescription needs to be prescribed with an individualised approach that takes into account level of adiposity. The goal of exercise prescription for the obese should therefore be to determine the intensity and modality of exercise that does not activate compensatory behaviours, as this may in turn negate the beneficial effects of the additional energy expenditure of exercise. This study confirms that during the initial phase of an exercise-based weight loss intervention, the majority of obese women compensated for some, if not all, the energy cost of the exercise sessions by reducing NEAT. Whether this compensatory behaviour continues beyond the first month of an exercise program, particularly after training adaptations in cardiorespiratory fitness are realised, cannot be discerned from the current study. However these results do provide a rationale for why the magnitude of weight loss achieved is often less than predicted during exercise interventions. Further research is required to examine the temporal pattern of compensation in NEAT, and the relationship between the time courses of NEAT compensation relative to physical fitness improvements. The results from this thesis support the use of activity monitors such as accelerometers during weight loss interventions to track NEAT and provide objective feedback regarding compensatory behaviours to clinicians and the obese individuals.

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