Given the global food price spike experienced in 2007/8, the core question of this research is, ‘what was the impact of the rising food prices on household welfare in Zambia'? Taking an empirical approach and using micro-economic methods, four welfare outcomes are assessed: consumption, equality of income distribution, poverty and nutrition. The 2006 and 2010 cross-section household surveys - Living Conditions Monitoring Surveys (LCMS) - are primarily used to answer the question. The thesis first assesses the changes in consumption patterns across time, geographical locations and quintiles. The short-term distribution of income from the rise in prices is then analysed using non-parametric methods to show the likely winners and losers from the price spike and the subsequent impact on poverty. These results are supplemented by a supply response as an attempt to understand longer-term poverty effects. The final empirical exercise focuses on nutrition outcomes. The thesis confirms the hypothesis that on average, urban households may suffer a welfare loss but rural households may gain. In the case of maize grain, the results suggest that the highest gain may accrue to rural households clustered around the poverty line. Furthermore, the findings suggest that, while overall poverty may increase in the short-run, the long-run impacts of rising food prices (once supply response are accounted for) may lead to a marginal decline in poverty. Finally, we observe that the slight increase in income, from selling maize, among some rural households may not necessarily lead to an improvement in nutrition outcomes. In particular, while rural households exhibit a small net rise in income from an increase in maize prices, the impact on stunting levels among children below five years appears to be regressive in both urban and rural areas. The overall results of this research strengthen the case for contextual impact analysis of covariate shocks and also highlight the policy challenges arising from such conflicting results.

The amount of food thrown away by UK households is substantial and, to a large extent, avoidable. Despite the obvious imperative for research to identify key factors that motivate, enable or prevent household food waste reduction, little research to date has directly addressed this objective. The research presented in this thesis had two clear aims: (1) to investigate antecedents of household food waste reduction and barriers to change, and (2) to explore whether self-affirmation techniques can increase motivation to reduce household food waste. Four empirical studies were conducted. The first study qualitatively explored thoughts, feelings and experiences of 15 UK household food purchasers. Analysis revealed seven core categories representing both motivations and barriers to household food waste reduction. The second study (N = 279) applied an extended theory of planned behaviour (TPB) model to predict household food waste reduction intention and behaviour. Results revealed that the extended TPB variables predicted 64.55% of intention to reduce household food waste and 5.03% of the variance in household food waste behaviour. Studies 3 and 4 explored whether self-affirmation techniques would promote openness to information detailing the negative consequences of household food waste. Study 3 (N = 224) found that self-affirmed participants reported more positive cognitions towards household food waste reduction on a number of outcomes compared to their nonaffirmed counterparts. However, there was no impact of the self-affirmation manipulation on behaviour at follow-up. Study 4 (N = 362) failed to replicate the impact of selfaffirmation on cognitions. However, self-affirmed participants reported that they threw away less household food waste at follow-up. Further research in the context of selfaffirmation on food waste reduction behaviour is required.

There is a strong body of psychological research implicating the mass media in the aetiology of adolescent girls' negative body image and eating behaviours. The present thesis aims to extend this research by examining potential factors – namely, media type, body perfect internalisation and materialism – that make girls more vulnerable to the negative impact of the mass media. An initial meta-analysis (Chapter 3) collated the findings of existing research examining the impact of ‘body perfect' media on adolescents' body image; examining gender, age and media type as moderators of this effect. Chapter 4 examined the relative roles of both media type and media model identification (a key dimension of body perfect internalisation), within the mass media and body image relationship. Using both survey and experimental methods (N = 199), it was found that adolescent girls' habitual tendency to identify with media models, was a more potent vulnerability factor within the mass media and body image relationship, than media type. Due to the limitations associated with existing measures of body perfect internalisation, a new measure of body perfect internalisation was developed in Chapter 5 (N =373), which was subsequently utilised in the final experiments of the thesis. Chapter 6 demonstrated that acute music video exposure had a more potent negative impact on girls' body image than still media images (N = 142); an effect that was fully mediated by wishful character identification and also moderated by body perfect internalisation. Chapter 7 consists of two studies that demonstrate the important role which materialism plays within the mass media, body image and eating behaviour relationship. In Study 1, structural equation modelling identified a direct pathway between materialism and restrained eating that was independent of body image (N = 199). This finding was further replicated in an exposure experiment, which demonstrated that brief exposure to materialistic media causes acute diet-like behaviours in adolescent girls (N = 180).

Rugby is a complex, high-intensity, intermittent, collision sport with emphasis placed on players possessing high lean body-mass and low body-fat. After an 8-12 week pre-season focused on physiological adaptations, emphasis shifts towards optimizing competitive performance and recovery through periodising player’s diets and training. In Chapter 4 the physiological demands and nutritional intakes of 45 elite rugby players were assessed during a pre-season through a battery of strength and conditioning tests, quantification of training demands using global positioning system (GPS), and two 24-hour diet recalls. Mean weekly distance covered during training was 9774 ± 1404 and 11585 ± 1810 m with a total mean weekly session RPE (sRPE) of 3398 ± 335 and 2944 ± 410 arbitrary units (AU) for forwards and backs respectively. Mean daily energy intake was 14.8 ± 1.9 and 13.3 ± 1.9 MJ, carbohydrate (CHO) intake was 3.3 ± 0.7 and 4.14 ± 0.4 g·kg-1 body mass, protein intake was 2.52 ± 0.3 and 2.59 ± 0.6 g·kg-1 body mass, and fat intake was 1.0 ± 0.3 and 0.95 ± 0.3 g·kg-1 body mass for forwards and backs respectively. Markers of physical performance (1-RM strength, speed, and repeated sprint tests) and anthropometry (body fat, and estimated lean mass) significantly improved in all players, despite players’ self-selecting a ‘low’ CHO ‘high’ protein diet. It may be speculated therefore that ‘low’ CHO ‘high’ protein intakes are appropriate to fuel the pre-season, although whether these intakes are sufficient to fuel the in-season is unknown. Once the demands of the pre-season were established, the next aim of the thesis was to examine if requirements changed during the playing season, as well as quantifying energy expenditure. In Chapter 5 in-season training load using GPS and sRPE, alongside six-day assessments of energy intake (EI) and energy expenditure (EE) was measured in 44 elite Rugby Union players. Mean weekly distance covered was 7827 ± 954 m and 9572 ± 1233 m with a total mean weekly sRPE of 1776 ± 355 and 1523 ± 434 AU for forwards and backs, respectively. Mean daily EI was 16.6 ± 1.5 and 14.2 ± 1.2 MJ, and EE was 15.9 ± 0.5 and 14 ± 0.5 MJ for forwards and backs respectively. Mean CHO intake was 3.5 ± 0.8 and 3.4 ± 0.7 g·kg-1 body mass, protein intake was 2.7 ± 0.3 and 2.7 ± 0.5 g·kg-1 body mass, and fat intake was 1.4 ± 0.2 and 1.4 ± 0.3 g·kg-1 body mass for forwards and backs respectively. All players who completed the food diary self-selected a ‘low’ CHO ‘high’ protein diet during the early part of the week which increased in the days leading up to a match. EI and EE followed an inverse trend, with expenditure exceeding intake during the first four-days of the training week and then reversed in the day leading up to competition with intake exceeding expenditure. Despite this, mean EI exceeded EE which alongside no micronutrient deficiencies, suggest that the current dietary practices of these elite rugby players seem sufficient to fuel training during the in-season, providing energy intake and CHO are increased leading up to a match. Given that intakes reported in this study are still below recommended CHO intake for elite athletes (Burke et al 2011), however, it is still possible that such intakes are not optimal for match day performance. Given that in Chapters 4 and 5 it was found that elite Rugby players appear to deliberately select a low carbohydrate intake, it was deemed important to assess match-play glycogen demands following a low (the amount self selected in chapter 4) and higher (the amount self selected leading in to competition in chapter 5) carbohydrate diet. Therefore, in Chapter 6 the metabolic and physiological demands of rugby competition was assessed in 16 professional Rugby League players following either a 6g·kg (HCHO) or 3g·kg (LCHO) CHO diet for 36-hours. Muscle biopsy and blood was collected, alongside monitoring internal and external load through GPS and heart rate. Mean distance covered was 93.7 ± 12.4 and 89.4 ± 9.8 m·min-1 in the first, and 85.3 ± 13.1 and 86.9 ± 9.7 m·min-1 in the second half for HCHO and LCHO conditions respectively. Mean %HRpeak was 82.9 ± 6.1 and 81.9 ± 7.2 % in the first and 82.5 ± 7.5 and 78.4 ± 10.5 % in the second half for HCHO and LCHO conditions respectively. Mean muscle glycogen was 448.6 ± 50.8 and 444.2 ± 81.1 mmol·kg d·w-1 pre-game, and 243.4 ± 42.5 and 297.7 ± 130.5 mmol·kg d·w-1 post-game for HCHO and LCHO conditions respectively. Results demonstrate that a competitive RL match can result in ~40% muscle glycogen depletion and that match-day performance variables did not differ between conditions. It was postulated that an absolute amount of ~600 g CHO consumed 36-hours pre-match is a recommended strategy for rugby league players, although optimal dietary strategies to refuel after rugby competition are unknown. The final aim of the thesis was to examine if the current post exercise CHO guidelines are appropriate for rugby players. In Chapter 7 the magnitude of muscle glycogen repletion after consuming an immediate, or delayed re-feed post Rugby League Match Simulation Protocol (RLMSP) was assessed in 16 university rugby league players using muscle biopsy and blood letting techniques. Muscle glycogen very likely increased 48-h post-simulation (272 ± 97 cf. 416 ± 162 mmol·kg-1d.w.) after an immediate re-feed, but changes were unclear (283 ± 68 cf. 361 ± 144 mmol·kg-1d.w.) after a delayed re-feed. Creatine Kinase (CK) almost certainly increased by 77.9 ± 25.4 % (0.75 ± 0.19) post-simulation for all players. Player Load (8 ± 0.7 AU) and %HRpeak (83 ± 4.9 %) were consistent with professional RL match-play. Time to exhaustion performance test revealed no difference between conditions. This study found that simulated RL match-play elicits lower muscle glycogen utilisation (21 cf. 40 %) despite similar player load and metabolic demands to a professional RL match. This may be attributed to the difficulties of replicating extensive structural damage and physical exertion from collisions during a simulation. It was also found that substantial muscle glycogen resynthesis was possible in the immediate dietary re-feed group despite evidence of muscle damage via increased blood proteins, indicating that with appropriate feeding strategies it is possible to replenish a damaged muscle. Taken together, this thesis has characterized the training demands and energy balance of elite rugby players during the pre-season and in-season, alongside quantifying the metabolic demands of elite rugby match-play, and the most appropriate strategies to load and replenish muscle glycogen around such exercise. Future studies must now further titrate these studies and assess muscle glycogen utilisation over a number of games whilst assessing the glycogen content of individual muscle fibre types.

The prevalence of maternal obesity is on the increase, compromising both maternal and foetal health. Previous intervention studies have been designed to limit the amount of gestational weight gain but in the absence of UK guidelines relating to optimum weight change in obese pregnancies and the negative experiences of obese women with regard to previous weight loss attempts it is reasonable to ask whether this is the most effective approach. It has been demonstrated that maternal dietary intake can impact on gestational weight gain and birth weight but there is little in the way of research into the impact that quality of diet has on outcomes. Aims: To measure the quality of maternal dietary intake and weight change against pregnancy and birth outcomes and to explore and gain insight into the lived experience of obese pregnant women with a view to informing guidelines. Methods: Pregnant women with a BMI≥35kg/m2 were recruited from antenatal clinic and asked to complete 3 day food diaries at 16,28 and 36 weeks gestation, The diaries were verified using a food atlas and analysed using Microdiet. A subset of women were then followed up and interviewed regarding their lived experience of obesity. Results: The women’s dietary intake deteriorated over the duration of pregnancy and there were significant associations between some micronutrients and pregnancy and birth outcomes. Women with a BMI 35-39.9kg/m2 were most likely to gain weight. Conclusion: The dietary intake of obese pregnant women is an important predictor of pregnancy and birth outcomes and it was demonstrated that the quality of diet significant deteriorated over the duration of pregnancy. Interventions designed to increase the quality of diet are urgently required.

This work addresses the use of microwave techniques to determine quality parameters in cured meat. The first approach is online monitoring of weight loss in the meat curing process, which is a significant measurement for the meat industry because the weight loss is used as a method of tracking the curing process. Currently, weight loss is measured by using ordinary weighing scales, which is a time-consuming and impractical technique. Thus, a novel method is required to simplify the process by implementing an online monitoring technique. In this work, a set of microwave sensors were modelled using High Frequency Structure Simulation Software and then constructed and tested. Weight loss of the sample and change in the S11-parameter illustrated a strong linear relationship (R2 > 0.98). The prediction model then was developed using the Partial Least Squares method, which exhibited a good capability of microwave sensors to predict weight loss, with R2p (prediction) = 0.99 and root mean square error of prediction (RMSEP) = 0.41. The second approach is to determine water activity (aw) in cured meat, which is the parameter that describes available water for microorganisms and influences different chemical reactions in the product. For the cured meat industry, aw is the only moisture related measurement that is an accepted Hazard Analysis and Critical Control Point plan. This is important for safety reasons, but also for energy optimisation since curing requires controlled continuous temperature and humidity. Currently, aw is being measured by the meat industry using commercially available instruments, which have limitations, namely being destructive, expensive and time-consuming. Few attempts to develop non-destructive methods to predict aw have used X-ray systems (namely Computed Tomography), Near Infrared (NIR) and Hyperspectral Imaging (HSI). Although the techniques provided promising results, they are expensive, impractical and not commercially available for the meat industry. The results from the microwave sensors demonstrated a linear relationship (R2 = 0.75, R2 = 0.86 and R2 = 0.91) between the S11 and aw at 2.4 GHz, 5 GHz and 7 GHz, respectively. The prediction model exhibited a good capability of the sensors to predict aw (R2p = 0.91 and RMSEP = 0.0173).

Low childhood physical activity levels, and high paediatric overweight and obesity levels, carry a considerable burden to health including cardiometabolic disease, low fitness, and reduced psychosocial well-being. Numerous school- based physical activity interventions have been conducted with varied success. This thesis therefore aimed to develop and investigate the effectiveness of the Children's Health, Activity and Nutrition: Get Educated! (CHANGE!) project, which was a school-based curriculum intervention to promote healthy lifestyles using an educational focus on physical activity and healthy eating. The purpose of the formative study (Study 1) was to elicit subjective views of children, their parents, and teachers about physical activity to inform the design of the CHANGE! intervention programme. Analyses revealed that families have a powerful and important role in promoting health-enhancing behaviours. Involvement of parents and the whole family is a strategy that could be significant to ~ncrease children's physical activity levels. There is large variation in the cut-points used to define moderate physical activity (MPA), vigorous physical activity (VPA) and sedentary time, which impacts on accurate estimation of physical activity levels. The purpose of Study 2 was to test a field-based protocol using intermittent activities representative of children's physical activity behaviours, to generate behaviourally valid, population-specific cut-points for sedentary behaviour, MPA and VPA. These cut-points were subsequently applied to CHANGE! to investigate changes in physical activity (Study 3). The CHANGE! intervention resulted in positive changes to body size and VPA outcomes after follow-up. The effects were strongest among those sociodemographic groups at greatest risk of poor health status. Further work is required to test the sustained effectiveness of this approach in the medium and long-term. Further, the development of an inexpensive and replicable field- based protocol to generate behaviourally valid and population-specific accelerometer cut-points may improve classification of physical activity levels in children, which could enhance subsequent intervention and observational studies.

The work described in this thesis addresses two questions relating to benefits of dietary omega-3 fatty acids (n-3 LCPUFA). Accretion of research knowledge indicates that adequate n-3 LCPUFA intakes may be instrumental in maintaining good health throughout life, including in the optimisation of cardiovascular health. Sources of n-3 LCPUFA traditionally include fish oils but concern regarding long-term sustainability of fish stocks has led to investigation of alternative sources. Krill oil, obtained from the crustacean Euphausia superba, contains n-3 fatty acids as phospholipids and triglycerides, astaxanthin and related carotenoid pigments, and has been proposed as a more effective alternative than triglyceride oils. Some foods rich in n-3-LCPUFA, including prawns, also contain cholesterol; concern regarding possible adverse health effects of such dietary cholesterol has led to public health advice to limit intake of these potentially beneficial foodstuffs. These questions are addressed in two food intake studies in male volunteers by monitoring markers of cardiovascular health, food intake and biochemical markers of compliance. Firstly, prawns and a white fish control were compared for effects on lipoprotein profiles and other markers. Dietary supplementation with 225 g prawns daily for 4 weeks was associated with a decrease in ApoB of 7.8mg/dL compared an increase (+2.4 mg/dL) for the white fish control. Participants with BMI > 25 kg/m2 also showed a reduction in plasma TAG (0.17 mmol/L) compared with baseline following prawn intake; those receiving the control showed an increase in plasma TAG (0.30 mmol/L), a decrease in HDL-C, and increases in VLDL-C and sdLDL-C. No overall adverse effect was found for prawns compared with processed white fish. Secondly, effects were compared of fish oil and krill oil on cardiometabolic profiles of a cohort of men with metabolic syndrome, using anthropometric measurements, biochemical markers of cardiovascular health and assessments of food intake. Krill oil and fish oil at the doses used showed no overall difference in effect on MetS markers after 6 weeks; correlations between magnitude of reduction and baseline measurement were observed in both groups for TAG, fasting glucose, NEFA and sdLDL after 3 weeks on both supplements, and for glucose and cholesterol after 6 weeks of fish oil. Comparison of analytical methods was also undertaken during both studies; use of a point-of-care system using capillary blood correlated well with plasma biochemistry using venous blood, while the Hirano method for sdLDL measurement correlated favourably with more labour-intensive centrifugation techniques. Limitations of the methods used are discussed, and proposals put forward for future work, including improving compliance through the use of newly emerging technologies such as metabolomics.

Obesity is a complex condition that affects all age groups and socioeconomic strata and places significant burdens on health and social care systems in both developed and developing countries. Overeating and a lack of exercise, along with smoking and high alcohol use, are the most common causes of non-communicable diseases, which account for almost two-thirds of global deaths each year. This programme of PhD research aimed to better understand dietary and other health risk behaviours by considering the influence of evolutionary behavioural strategies, while controlling for other determinants of health risk behaviours, including childhood experience and socioeconomic variables. In the first study, young adults (n=393; aged 18-30 years) completed a bespoke self-report questionnaire and provided data on their developmental experiences and their socioeconomic environments, in addition to a range of behavioural choices and evolutionary strategies (e.g. reproductive behaviour). In the second study, a secondary analysis of the second iteration of the North West Mental Well-being Survey (NWMWBS) 2012/13 was undertaken to supplement findings from study 1. These studies were analysed using regression analysis and Latent Class Analysis. Across both studies, there was a clustering of risk behaviours. Adverse childhood experiences and lower socioeconomic status were found to be predictive of health risk behaviours, including unhealthy eating, binge drinking and smoking cigarettes. Various evolutionary behavioural strategies were found to be predictive of health risk behaviours. Reproductive strategy was found to be predictive of BMI; health offsetting was found to be predictive of risky eating behaviour and physical activity; investing behaviour was found to be predictive of BMI, general health risk taking, binge drinking, current daily smoking, and violence; altruism was found to be predictive of eating preference; trust was found to be predictive of general health risk taking, current daily smoking, and physical activity; cooperation was found to be predictive of current daily smoking; and, planning behaviour was found to be predictive of current daily smoking, and risky sexual practices. Overall, the research suggests that childhood experiences and socioeconomic inequality are key determinants of behavioural strategies, and that such strategies are likely to be adaptive.

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