In the modern day lifestyle, two factors have been primarily associated with the rising prevalence of obesity, the increasing consumption of energy dense food and the decline in physical activity (Varo et al. 2003). With an estimated 500 million adults thought to be obese worldwide (WHO 2013), it is clear we need to stem this epidemic. Much emphasis on research has already been placed on developing strategies to manipulate these two factors and reduce the incidence of obesity but at present an effective and sustainable solution seems elusive. One thing that is clear, with the increase in the cases of obesity, there has also been a concomitant rise in our intake of high refined carbohydrates and sugars. Moreover, the consumption of sugar-sweetened beverages (SSB) has increased over the past four decades (ERS 2004) and consequently, their association with obesity has been well documented (Nissinen et al. 2009, Olsen, Heitmann 2009, Hu, Malik 2010). To undo the damage of diets high in refined carbohydrates and sugars, exercise has been thought to be the answer by many but as yet this has not yielded convincing success in promoting weight loss and repairing the alterations to metabolism associated with chronic hyperglycaemia and obesity. In the first experimental chapter, an in vivo and in vitro approach was used to investigate the effects of high glucose availability on skeletal muscle metabolism. In our in vivo study the effects of 4 weeks sugar-sweetened beverage (SSB) supplementation was investigated on lean, healthy, lightly active individuals with very little or no previous consumption of SSB. Muscle biopsies were taken from each participant pre and post 4 week intervention and through western blotting and real time reverse-transcriptase polymerase chain reaction (RT-PCR), protein and gene expression of several metabolic markers and glucose regulating factors was measured. In the in vitro study, primary human muscle cell cultures were exposed to chronic hyperglycaemia and compared to cultures with normal glucose concentrations for 7 days. Analyses revealed both the in vivo and in vitro studies demonstrated a shift towards increased glycolytic activity and reduced oxidative activity, similar to that found in type 2 diabetes mellitus patients. Furthermore, in both studies an increase in MondoA expression was observed and in the in vitro cell cultures TXNIP expression was also increased. The fact that the findings from in vivo study are comparable to those in the in vitro study, demonstrates the potency of high glucose availability on skeletal muscle. The results are even more alarming as the participants were young healthy individuals, not overweight or obese and with very little previous history of SSB consumption, highlighting just how damaging the effects of SSBs can be and the significant role they play in the development of obesity. In chapter 3 and 4, long term exercise interventions were used to investigate the effects of chronic exercise on metabolism, body composition and energy balance of lean and overweight or obese (Ov/Ob) sedentary women. The aim of these studies was to investigate the compensatory mechanisms in Ov/Ob individuals preventing adaptations to exercise. A novel approach to long term exercise with ad libitum energy intake was used in both of these studies, where participants were not recruited with a desire to lose weight and they were also naïve to the true aims of the study. In chapter 3 a 4 week exercise training intervention was used and in chapter 4 an 8 week training intervention was used. Both studies utilized a group based circuit training format 3 days per week, the 4 week intervention was at a moderate intensity and the 8 week intervention had both a high and low intensity exercise group. Dual-energy xray absorptiometry (DXA) and indirect calorimetry, at rest and during exercise, were used to give and overview of participants’ anthropometric and metabolic profiles, before and after inventions. Blood samples were collected for analysis of several key hormones regulating metabolic adaptations and energy homeostasis in response to exercise. Diet records were also collected from participants to measure any alterations in energy and macronutrient intake. Neither the 4 week nor the 8 week exercise intervention demonstrated significant weight loss of either the lean or Ov/Ob individuals. However, in both the interventions lean participants displayed losses in percentage body fat, even though no weight loss was seen overall. These findings reaffirm those reported in previous literature that during an increase in exercise induced energy expenditure, Ov/Ob individuals with respond with a concomitant increase in energy intake, negating any possible weight or fat loss and possibly even promote weight gain. On the contrary lean individuals do not display the same over-compensation to the increased energy expenditure and there energy intake is unchanged. It is hypothesized that the lean participants were able to display a reduction in body fat through the ability to exercise at a higher absolute intensity. Based on analysis of blood samples, it was possible to further investigate possible regulators that may control a homeostatic mechanism, preventing weight/fat loss in obese individuals. In the 8 week study a significant drop in amylin concentrations was observed in the Ov/Ob participants, compared to no change in the lean subjects. It was proposed that Ov/Ob individuals, who also displayed heightened insulin resistance and hyperleptinemia, have developed an overreliance on amylin for satiety signalling. Moreover, in conjunction with the inability to achieve an absolute intensity high enough to induce adaptive responses to exercise, Ov/Ob individuals with reduced amylin secretion, increase energy intake after exercise and prevent any possible weight or fat loss. Additionally, adaptive responses to exercise were seen in both the 4 week and 8 week exercise studies, Ov/Ob participants displayed a positive movement away from a preference to rely on anaerobic metabolism at a low exercise intensity preintervention, towards more anaerobic metabolism post-intervention. In addition, following the 8 week exercise intervention, the inter-individual variability in response to exercise was investigated. Participants were separated based on their heart rate response, into responders and non-responders and it was revealed that those who clearly demonstrated adaptations, also tended to lose more weight, maintain a negative energy balance, and avoid the maladaptive decrease in amylin concentrations. Suggesting these individuals do not develop the hypothesized leptin resistance, and overreliance on amylin signal, meaning they do not overcompensate for increased exercise induced energy expenditure and can lose weight. In conclusion, it is clear that an exercise only or a one size fits all approach is not the answer in the treatment of obesity. A more multi-dimensional approach is necessary and in order to reduce many of the associated lifestyle disease markers, both diet and levels of physical activity must be addressed in the obese. Recommendations for future intervention studies must address this and combine a diet low in refined carbohydrates and sugars, with high intensity interval training and resistance exercise.

Cardiovascular diseases (CVD) remain one of the leading causes of death in the world. Despite the decreasing incidence of CVD in Western countries, due to the aging population, the prevalence is still increasing. High blood pressure (BP) is the most important modifiable risk factor for CVD, due to its high mortality rate. The impact of diet on CVD and its risk factors is well described. Epidemiological studies have demonstrated an inverse association between high milk consumption and lower BP. Milk is a complex, nutrient-dense food containing an array of essential nutrients. It is, however, of great scientific interest to determine which constituent is responsible for this beneficial effect. Milk proteins have been shown to exert angiotensin-converting enzyme inhibitory (ACEi) effect, which is a key enzyme in BP regulation. After an extensive literature search, a meta-analysis was performed to examine the impact of the casein-derived lactotripeptides on BP. This study demonstrated hypotensive effects in humans, specifically in Japanese individuals. A clear gap in the current scientific knowledge was well-designed randomised controlled trials to examine the effects of intact milk proteins on BP and other novel and classic risk markers for CVD. The findings from my randomised, controlled, double-blind, chronic intervention study showed that whey protein consumption (2 x 28 gld) for 8 weeks reduced 24-h ambulatory BP, peripheral and central BP assessed by applanation tonometry as well as improved endothelial function (flow-mediated dilation› FMD) compared to control (2 x 27 gld maltodextrin) in 38 hypertensive participants. Whey protein also reduced fasted total cholesterol (TC) and triacylglycerol (TAG) compared with control, while Ca-caseinate (2 x 28 glday) improved endothelial function (FMD) and lowered fasted TC compared with control. Both whey protein and Ca-caseinate decreased adhesion molecules compared to control (sICAM-l was decreased by whey protein and VCAM-l by Ca-caseinate). These changes were achieved without significant changes in body weight or habitual diet of the participants. The acute study also demonstrated beneficial effects of dairy proteins after two high-fat meal challenges in 27 mildly hypertensive adults: whey protein (28 glmeal) decreased BP between the two test meals compared with Ca-caseinate (28 glmeal) and control (27 glmeal), and also improved arterial stiffness (augmentation index) and maintained endothelial function (FMD) over the 8-h postprandial period. Furthermore, although whey protein increased insulin response to a similar magnitude to the carbohydrate-based control, lower postprandial glycaemia was maintained by whey protein. Furthermore, Ca-caseinate lowered postprandial TAG response compared with whey protein. The purported molecular mechanisms underlying the impacts of dairy proteins on the cardiovascular system still remain unclear. The in vitro ACEi experiment presented in this thesis confirmed the hypotensive effects of whey protein over Ca-caseinate and control, however serum samples failed to confirm this ACEi activity. In summary, milk proteins, particularly whey protein, had important fasted and postprandial benefits to the cardiovascular system compared with control, however concomitant consumption of dairy proteins may be of further benefit due to their different kinetics in the gastrointestinal system. Future research should address the impacts of milk proteins in type 2 diabetic patients with impaired glucose metabolism .

The gradually increasing numbers of international students known as “sojourners” who stayed for a short period in the host country have received growing interest from academics, practitioners, and policymaker around the world. This was majorly due to the contribution from international students’ fees and spending, and from the unique and subsequent changes in the culture and practice of this student group. However, for the international students, migration became a turning point for their independent life in the new country. The experience was more challenging because it required a personal commitment especially on food provisioning responsibilities and the development of a new food choice system alongside the stressful academic roles and responsibilities. Therefore, the context of international students’ food adjustment experience or food acculturation received dedicated attention through this study. Furthermore, this study aimed to explore the food acculturation process of new international students during the early phase of transition in the UK based on the life course perspective. The life course perspective takes into consideration the transition phase which is a very important turning point that influenced the food acculturation of the international students. Three objectives has been established for this study to explore the exposure, experience, and perception of new food choice in the UK; to identify the influences of life course perspective over food choice decision; and to examine the food acculturation process when adjusting and managing food provisioning practice at the early stage of transition. Based on an interpretivist view, a series of qualitative approach was employed during the preliminary study and main data collection. The purpose was to allow access to the lived experiences of the students’ new food choice process. The preliminary study adopted was focus group discussions using a sample of ten existing international students and the study was conducted from December 2012 until January 2013. The themes developed from the preliminary findings and the key issues generated from relevant literature were applied to develop the observation and interview protocol for the main study. Next, two qualitative inquiries of observed accompanied shop and in-depth interviews were applied for the main study using a sample of twenty new international students who just recently arrived at the UK. The main data collection began in October 2013 when the students first arrived and ended early of March 2014. The timeline allowed the occurrence of more food exposure and experience of new food choice, allowing patterns and changes of food acculturation to emerge over time. The major themes identified from the preliminary study were the influence of life course perspective influences of new food choice, the food adjustment experiences, challenges and strategy, and food acculturation process during transition. The main findings concluded three main themes from the observed accompanied shop and in-depth interviews in accordance to this study’s objectives: (1) the exposure, experience and perception on the new food choice in the UK, (2) the Life Course influences on food choice decisions, and (3) the food acculturation process of international students. The main findings showed that (1) migration was a turning point, which contributed towards the diverse representations of the international students’ exposure, experience, and perception of new food choice; (2) the reliance and support system of the new food choice decision from co-national friends and online friendship network; (3) the diverse challenges in managing new roles and responsibilities of food provisioning practice, including grocery shopping, food preparation and cooking, and consumption practices, (4) the importance of self-efficacy and acquiring of food provisioning skills and competencies for a positive food adjustment experience, (5) the influence of Life Course elements of personal and social factors, cultural ideals, resources, and current context and trends in the in the food choice decision process, (6) the transformation of food choice process, which implicated a food acculturation process that includes integration, assimilation, separation, marginalisation, and a repertoire of strategies based on situational factors. The key findings indicated that the adjustment experience in the early phase of transition greatly influenced the food choice decisions of the new international students. The main contribution of this study relies on the application of the life course Perspective in the study of food acculturation because of the consideration of migration as a turning point in the transition of food choices. In contrast to other studies on international students’ food choice and dietary acculturation, this study provides a valuable lens that includes the food choice process at the point of grocery shopping, preparation and consumption, which gave a wider context on the stages in food decision-making process. This study contributes towards the body of knowledge on international students’ adjustment studies, the Life Course experience influence on food choice, and the food acculturation field. The results from this study can provide a better understanding on new food choice decision among the international students during their transition in the new country. Universities and other stakeholders such as local authorities and the public health provider may use these findings to support and develop strategies to improve the adjustment experience, which in turn, may attract more international students. Food providers such as restaurants, food manufacturers, food suppliers, retailers and specialty (ethnic) supermarkets can also benefit by understanding the challenges in food choice, accessibility to available food towards improving, strategising and incorporating plans that are personalised to the international students’ needs.

No description available.

Vitamin D deficiency is a common occurrence globally and in particular, in at risk populations such as young children, pregnant women and the elderly. This is mainly due to the lack of natural dietary sources of vitamin D and the limited cutaneous production of vitamin D3. Vitamin D has been associated with a number of non-skeletal diseases and outcomes e.g. cardiovascular disease (CVD), diabetes, pre-eclampsia and low birth weight (Muscogiuri et al. 2012; Beveridge & Witham 2013; Pérez-López et al. 2015), however, these associations remain to be proven. The aim of this thesis was, firstly, to examine the incidence of vitamin D deficiency in a number of cohorts across the lifecycle, using a validated Ultra-Performance Liquid Chromatography- Tandem Mass Spectrometry (UPLC-MS/MS) assay. A second aim was to examine the associations between 25OHD and a number of non-skeletal health outcomes across the lifecycle, and, thirdly and finally, to determine the dietary and supplement sources of vitamin D in two of these cohorts. The measurement of vitamin D metabolites was conducted using a validated UPLC-MS/MS assay. Vitamin D deficiency (<25 nmol/L) was evident in all three cohorts, 26.6%, 40.0% and 14.8%, in the Hyperglycemia and Pregnancy Outcomes study (HAPO), the MEDiterrean Diet in Northern Ireland (MEDDINI) trial and the EURopean EYE (EUREYE) study, respectively. 25-hydroxy vitamin D (25OHD) was not associated with glucose, insulin or lipid metabolism in pregnant women. A positive association was found with maternal 25OHD and birth weight SDS, in addition, a risk reduction for low birth weight as maternal 25OHD increased was observed. An association was also observed between maternal 25OHD and a marker of cord beta cell function. In the older European cohort, an association, following adjustment for a number of confounders, was detected between 25OHD and diabetes, with no association observed between 25OHD and CVD in the same cohort. It was observed that a Mediterranean diet (MD) significantly increased 25OHD levels in a Belfast CVD patient group and this was more than likely due to increased fish intake. This was further reiterated in the EUREYE cohort where oily fish was significantly associated with increased 25OHD levels. Furthermore, in the EUREYE cohort, despite the lack of a seasonal effect on 25OHD levels, Bergen, had the highest concentration of 25OHD. This finding in Bergen, may be attributed to fish oil/omega-3 supplements as it was the only dietary source associated with 25OHD levels. Vitamin D deficiency was found to be commonplace across the lifecycle, and across Europe. The current analysis suggests that further investigation may be warranted on the relationship that exists between maternal 25OHD levels and the possible health implications for the offspring, such as risk of chronic diseases later in life. The findings also suggest that the use the MD diet can increase dietary vitamin D intake. This is more than likely due to the increased consumption of oily fish, which is supported by the association found in the EUREYE cohort. Furthermore, findings from the present analysis suggest that it may be possible to increase 25OHD levels to a sufficient level from oily fish or fish oil supplements only, as demonstrated by the findings from the Bergen centre in the EUREYE study. In conclusion, vitamin D deficiency is a mutual problem shared across the lifecycle. Practical and achievable methods to eradicate vitamin D deficiency should be established by public health agencies. There is a possibility that vitamin D deficiency may be associated with chronic diseases and other health outcomes throughout the lifecycle. Minimising vitamin D deficiency may help to reduce the risk for these health outcomes, however, causality still remains to be proven.

No description available.

Nutrition-oriented value chain analysis has been proposed to support the identification of solutions to nutrition problems, such as low fruit and vegetable (FV) intake. Through a case study of Fiji‘s FV sector, this thesis explores the application of the approach and aims to identify its strengths, limitations, and potential to inform public health action to increase FV intake. Following a review of models of value chain analysis, the strategic business management model was adapted and methods were selected to collect relevant data. Focus groups with urban consumers were used to establish what they value in FV. Following this, workshops, semi-structured interviews, and observations with chain actors and stakeholders were used to map three exemplar chains (amaranthus, papaya, and tomatoes) and investigate their performance in respect to delivery of consumer-defined value. Data were analysed thematically. Urban Fijians identified both price and quality as important to food choice and considered quality in terms of taste and appearance, perceived health properties, freshness, and convenience. Consumers described inconsistent availability and high prices as barriers to consumption. The exemplar chains were relatively basic, with most activities performed by farmers. Access to agricultural inputs was a challenge, as was limited transportation and market infrastructure. Actors tended to view consumers as driven by price and therefore focused on cost-minimisation rather than value addition. Most farmers received little information on supply and demand trends; however, strong relationships appeared to enhance product and information flows. Across the chains, high vulnerability to natural disasters impaired the delivery of consumer-defined value. The findings identify opportunities to enhance FV availability, affordability, and acceptability by promoting the qualities of FV that consumers value, reducing bottlenecks in the chains, and strengthening relationships between actors. They also suggest a benefit of the strategic business management model of value chain analysis for guiding research for nutrition.

Background: University represents a key event in the transition from youth to adulthood for a substantial proportion of young adults in the UK. There is evidence that UK university students consume poor quality diets, with potential long-term health implications. However, contemporary studies are scarce and limited in scope. Aim: This research aimed to explore the food choices of university students in the UK. Objectives were to: assess dietary adequacy and patterns among UK university students and associated socio-demographic and lifestyle characteristics; explore students’ experiences and values in relation to dietary patterns; and to identify students’ eating behaviours associated with body weight gain. Methods: A multi-methods research design comprising three phases of data collection was employed. An online food frequency questionnaire was administered to undergraduate students at five UK universities to assess dietary adequacy and patterns, with subsequent principal components analysis. Semi-structured qualitative interviews were conducted with a purposive sample of 25 undergraduate students and analysed thematically. An online survey among student members of a national weight loss programme was also undertaken with subsequent analysis. Findings: Dietary analyses revealed intake of several key nutrients and food groups outside of recommendations and four major dietary patterns: ‘vegetarian’; ‘snacking’; ‘health-conscious’; and ‘convenience, red meat & alcohol’. Several socio-demographic and lifestyle characteristics were associated with these patterns. Food choice experiences were complex and involved four substantive themes. Themes encompassed students’ relationships with peers and their dietary decisions at university, the impact of the unique university experience on food choice, aspirations of – and threats to – making healthful choices at university, and students becoming autonomous consumers. Cooking ability and consumption of fruit and vegetables, convenience/fast food and alcohol were significantly associated with body weight gain at university. Conclusions: There is heterogeneity in food intake and dietary practices amongst university students, with implications for enhancements to university food and welfare policies.

Maintaining an adequate food supply remains a global challenge, with hundreds of thousands of lives lost each year because of malnutrition, especially in developing countries. Although malnutrition tends to be more common in these countries, where there are shortages of food, in industrialised countries, more and more people are being diagnosed with malnutrition caused by food allergies. The main approach to managing allergies is to avoid certain foods, which may also lead to inadequate food intake and malnutrition. The first aim of this study was to develop a nutritional, ambient-stable, confectionary product containing seeds, nuts, and treacle with raw materials that are readily available in Middle Eastern and African countries. The second aim was to determine the effect of different thermal processing methods on the product with respect to Maillard reaction products (MRP) and antioxidant properties. The third aim was to measure the effect of different thermal processing methods and additives on the composition, solubility, structure, and immune reactivity of peanut allergens extracted from the product. The fourth aim was to test the effect of additives such as sodium bisulphite and ascorbic acid on the structure and allergenicity of peanut proteins. The second chapter of the thesis addresses product development based on literature-derived information of the proximate composition of various ingredients, including peanuts, sesame seeds, Nigella seeds, and treacle. The composition of the final product, called the black seed mix, was analysed by proximate analysis using approved AOAC methods. The amino acid composition was analysed by HPLC and the fatty acid composition by GC and minerals by atomic absorption spectroscopy. It was demonstrated that the product contains significant quantities of fat, carbohydrate, fibre, linoleic acid, protein and essential amino acids, magnesium, zinc and iron, to meet nutritional requirements for selected age groups. The third chapter deals with shelf stability and sensory analysis of the product. Water activity measurements of the fresh product, combined with knowledge of sugar content, led to categorisation of the product as a chewy, sweet confection. Texture analysis of the fresh product fell within an acceptable range, and the sensory evaluation proved to be acceptable. The vacuum -packed product was stable after one month’s storage under accelerated storage conditions (37°C). However, after 2 month’s storage, the product showed increased water activity, texture hardness, fracturability and cohesion strength, but this was still within an acceptable range according to published criteria. The peroxide value of fats also increased after 2 months accelerated storage, which was regarded as a limiting factor. The fourth chapter addresses the effect of different processing conditions on extracts of the black seed mix on Maillard reaction products (MRP; measured by spectroscopic absorbance and fluorescence), antioxidant activity (radical scavenging, ferric reducing and inhibition of lipid peroxidation measured by DPPH, FRAP, FTC, and TBA methods), and solubility (Bradford and Kjehldahl methods). The roasted product showed increased third stage MRP, which correlated with improved radical scavenging activity, similar ferric reducing activity but reduced inhibition of lipid peroxidation ability compared to the control and boiled sample. The boiled product resulted in higher intermediate-stage MRP, increased radical scavenging ability, reduced ferric reducing ability and increased inhibition of lipid peroxidation ability. The fifth chapter deals with the effect of processing and the addition of additives to the black seed mix on immune reactivity of peanut allergens (peanut-allergic patient sera) using the ELISA, SDS-PAGE, and Western Blot techniques. The results indicate that extract from the roasted product caused increased immune reactivity. I also report the loss of soluble peanut 7S and 11S in extracts from the boiled version, leading to reduced immune reactivity for the soluble fraction (ELISA and Western blot). I demonstrated that the addition of the approved food additive sodium bisulphite to the black seed mix lowers the immune reactivity of peanut allergens by ELISA, which was caused by reduction of disulphide bonds of the 11S peanut allergen as determined by SDS-PAGE. It is concluded that the preferred thermal processing method of the black seed mix would be boiling of the peanuts before addition to the rest of the ingredients and further processing.

Background: Unsafe drinking water and household air pollution are leading risk factors for diarrhoea and pneumonia, two major causes of death for young children. Rural areas are vulnerable due to unsafe water supplies and biomass burned indoors for cooking. Household water filters and portable fuel-efficient cookstoves could reduce these risks, but there is limited evidence of longterm uptake and impact. National Water Quality Study: To determine the extent of faecal contamination of household stored drinking water and associated risk factors in Rwanda, we conducted a nationally representative cross-sectional study. Only 24.9% (n=217) of household supplies met WHO Guidelines of no detectable faecal contamination (thermotolerant coliforms (TTC)). Risk factors for intermediate and/or high risk contamination (11-100 and 101+ TTC/100mL) included low population density, increased open waste disposal within a sector, lower elevation, water sources other than piped to household or rainwater/bottled, and occurrence of an extreme rain event the previous day. Thus, community level factors are associated with stored household water quality; observed contamination poses a health risk in Rwanda. Matched Cohort Study: We next conducted a matched-cohort study in 18 villages to assess uptake, exposure, and health impacts of a water filter and improved biomass cookstove intervention programme 13-24 months after receipt. Coverage and use of the filter and cookstove was high, but non-exclusive. The odds of detecting TTC were 78% lower in the intervention arm (OR 0.22, p < 0.001), with 50% lower odds of reported diarrhoea among intervention children < 5 (OR=0.50, p=0.03). The intervention was associated with 43.4% lower fine particulate matter in kitchens (p < 0.001), but geometric mean exposure remained above WHO targets for cooks (151 μg/m3) and children (175 μg/m3), and only marginally reduced among intervention cooks (22.2% lower, p=0.06). While the filter showed promise for health benefits, alternative household and community-level approaches for achieving clean, safe air are needed.