The primary objective of this series of experiments was to explore some of the reasons which lead to equivocal outcomes in the literature on dietary recommendations and to demonstrate the need for evidence-based data on well-trained and elite athletes. Therefore, the previous mentioned groups of athletes were recruited to participate in four research studies, each entailing a series of experimental trials. The data obtained were compared to previous research and/or to the established dietary recommendations. The aim of the first research study presented in this thesis (Chapter 2) was to examine the effects of Glycine-arginine-α-ketoisocaproic acid (GAKIC) supplementation on fatigue during high intensity, repeated cycle sprints in trained cyclists. It should be noted that despite the fact that studies on GAKIC supplementation involving well-trained subjects are lacking, athletes regularly use this commercially available supplement. This is is also the case for a vast range of other supplements whose suitability has been assessed in normal healthy subjects or recreationally active individuals. In the study presented in Chapter 2, 10 well-trained male cyclists completed two supra-maximal sprint tests each involving 10 sprints of 10 s separated by 50 s rest intervals on an electrically braked cycle ergometer. Participants ingested 11.2 g of GAKIC (according to protocols previously established in the literature) or Placebo (Pl) during a period of 45 min prior to the experimental trials. Peak power, mean power, fatigue index as well as heart rate (HR) and ratings of perceived exertion did not differ between conditions (GAKIC vs. Pl). Peak power declined from the 1st sprint (mean  SD) (Pl: 1332  307 W, GAKIC: 1367  342 W) to the 10th sprint (Pl: 1091  229 W, GAKIC: 1061  272 W) and did not differ between conditions (P = 0.88). Mean power declined from the 1st sprint (Pl: 892  151 W, GAKIC: 892  153 W) to the 10th sprint (Pl: 766  120 W, GAKIC: 752  138 W) and did not differ between conditions (P = 0.96). Fatigue index remained at ~38% throughout the series of sprints and did not differ between conditions (P = 0.99). HR and ratings of perceived exertion increased from the 1st sprint to the 10th sprint and did not differ between conditions (P = 0.11 and P = 0.83, respectively). The data reported, suggest that GAKIC has no ergogenic effect on repeated bouts of high intensity exercise in trained individuals. The reported data further contradicts previous performance studies where GAKIC was found to attenuate the decline in power output, improve muscle performance and delay muscle fatigue resulting in the improvement of total work during high intensity exercise. Notably, none of the previous studies involving GAKIC supplementation seem to control for a number of possible confounding factors that could have adversely affected the results. For instance, utilization of untrained individuals and failure to include baseline trials to establish the repeatability of performance trials leaves the reliability of the data open to question. Furthermore, the results in Chapter 2 highlight the importance of extrapolating decisions concerning the effectiveness of a marketed nutritional supplement from the best available research conducted on well-trained subjects. The aim of Chapter 3 was to assess the food and macronutrient intake of elite Ethiopian distance runners; a group of athletes that dominates endurance running. The results of the research allowed further examination and direct comparison of the nutrient intake to the established guidelines and previous studies conducted on African runners. The dietary intake of 10 highly-trained Ethiopian long distance runners, living and training at high altitude was assessed during a 7-day period of intense training prior to competition using the standard weighed intake method. Training was also assessed using an activity/training diary. Body mass (BM) was stable (i.e., was well maintained) over the assessment period (pre: 56.7 ± 4.3 kg vs. post: 56.6 ± 4.2 kg, P = 0.54). The diet comprised of 13375 ± 1378 kJ and was high in carbohydrate (64.3 ± 2.6% of total energy intake (TEI), 545 ± 49 g, 9.7 ± 0.9 g.kg-1). Fat and protein intake was 23.3 ± 2.1% TEI (83 ± 14 g) and 12.4 ± 0.6% TEI (99 ± 13 g, 1.8 ± 0.2 g.kg-1), respectively. Fluid intake comprised mainly of water (1751 ± 583 mL.day-1), while no fluids were consumed before or during training with only modest amounts being consumed following training. It was concluded that, as found in previous studies on elite Kenyan distance runners, the diet of these elite Ethiopian distance runners met most recommendations for endurance athletes in regard to macronutrient intake but not in regard to fluid intake. Nevertheless, it remains unclear in what way these differences in fluid consumption, before major competitions, have an impact on their performance. Therefore, Chapter 3 highlights the fact that more studies involving truly world-class athletes are required in order to assess and possibly improve the applicability of current recommendations to elite athletes. Chapter 3 also highlights the potential role of the commercial industry in the application of the science of exercise nutrition. Chapter 4 aimed to describe the drinking behaviours of elite male marathon runners during major city marathons. Retrospective video analysis of 10 male marathon runners during 13 major city marathons was undertaken. Total drinking durations during the marathons were determined by estimating the time spent ingesting fluid at each drinking station from video images. The ambient conditions during the 13 studied marathon races were 15.3 ± 8.6 oC (ambient temperature) and 59 ± 17% relative humidity; average marathon competition time was 02:06:31 ± 00:01:08 (h:min:s). Total drinking duration during these races was 25.5 ± 15.0 s (range: 1.6 - 50.7 s) equating to an extrapolated fluid intake rate of 0.55 ± 0.34 L.h-1 (range: 0.03 - 1.09 L.h-1). No significant correlations were found between total drink duration, fluid intake (rate and total), running speed and ambient temperature. Estimated BM loss based on calculated sweat rates and rates of fluid ingestion was 8.8 ± 2.1% (range: 6.6 - 11.7%). Measurements of the winner in the 2009 Dubai marathon revealed a BM loss of -9.8%. It was concluded that the most successful runners during major city marathons, drink fluids ad libitum (i.e., at one's pleasure) for less than ~60 s at an extrapolated fluid ingestion rate and is in accordance with the current recommendations by the American College of Sports Medicine of 0.4 - 0.8 L.h-1. Nevertheless, these elite runners do not seem to maintain their BM within the current recommended ranges of 2 – 3%. On the other hand, this apparently widely adopted ad libitum strategy during marathon racing seems to produce optimal/winning performances. This evidence and the finding that the runner, who set the previous world record (2008), finished a competitive race (Dubai, 2009) with a BM loss of 9.8%, suggest that a tolerable range for dehydration may exist. It is possible, that this tolerable limit of dehydration may not have a negative impact on running performance in elite runners and may even confer an advantage by preventing a significant increase in BM due to “over - consumption” of large volumes of fluid. Given the data extrapolated from “real world” studies (Chapters 3 and 4) and the established guidelines for fluid ingestion, the investigation in Chapter 5 aimed to examine a possible method that could bring together the established guidelines and the data extracted from “real world” studies. Therefore, the effects of a hyper-hydration method combining creatine (Cr) and glycerol (Gly) supplementation on thermoregulatory responses and running economy (RE) in hot and cool conditions were investigated. Cr•H2O (11.4 g), Gly (1 g•kg-1 BM) and glucose polymer (75 g) were administered twice daily to 15 male endurance runners during a 7-day period. Exercise trials were conducted pre- and post-supplementation at 10 and 35 °C and 70% relative humidity. Combined Cr and Gly supplementation increased BM and total body water by 0.90 kg and 0.71 L, respectively following supplementation. Despite the significant increase in BM, supplementation had no effect on oxygen uptake (V̇O2) and thus RE. Both HR and core temperature were attenuated significantly after supplementation. Combining Cr and Gly is effective in reducing thermal and cardiovascular strain during exercise in the heat without negatively impacting RE. The potential influence of the commercial industry on scientific objectivity, as well as the lack of properly evaluated, controlled and randomized studies are the two main weaknesses that prevent the establishment of well accepted guidelines for food and fluid intake of well-trained and elite athletes. The development of novel guidelines needs to be solely evidence-based. Therefore, in order to reach conclusions regarding specific categories of athletes, research should be conducted on homogeneous groups (i.e., either well-trained, or elite, or world-class). Furthermore, research must be conducted under environmental and other conditions that are equivalent to those met during ‘‘outdoor’’ exercise, in order to evaluate and even improve the prevailing recommendations.

The studies in this thesis aimed to develop and characterise a rodent model of meal feeding that would mimic aspects of human eating behaviour, leading to the overconsumption of calories and ultimately to obesity. In seeking to identify potential mechanisms that might be involved in the initiation of meals, a palatable scheduled feeding regime was utilised to induce a substantial food intake over short periods of time in rodents. This was done by providing scheduled access to a palatable diet for a 2h-period each day without imposed caloric restriction during the remainder of the day. Initially, the effects of different palatable diets were examined. Three of the four palatable diets resulted in a rapid adaptation of feeding behaviour and induced the consumption of large, binge-type meals in both Sprague Dawley rats and C57BL/6 mice. Candidate gene expression analysis by in-situ hybridisation during the two hour period leading up to scheduled feeding suggested that homeostatic neuropeptide systems in the hypothalamus did not have a major role in driving the consumption of these meals. Further characterisation of the scheduled feeding model revealed that palatable scheduled feeding does not lead to a relative hypophagic phase or an increase in pre-meal secreted gut hormones in anticipation of the scheduled meals. Interestingly, schedule-fed animals exhibited food anticipatory activity during the same period. In addition, scheduled-fed animals displayed only a mild obese phenotype but their metabolic health was adversely affected. Again using in-situ hybridisation, candidate gene expression was assessed during the scheduled feeding period itself, revealing a relationship with adiposity level but not with immediate feeding behaviour. Finally, in a ‘hypothesis-free' approach, gene expression was analysed by microarray at the point of initiation of scheduled feeding, with no apparent changes in gene expression levels. In conclusion, palatable scheduled feeding in mice and rats induces large, binge-type meals that appear not to be directly regulated by homeostatic neuropeptides in the hypothalamus. Investigations into forebrain candidate gene expression by in-situ hybridisation suggested that measuring mRNA levels might not be the optimal analytical approach to demonstrate an involvement of the reward-related signalling system. Alternative strategies for identifying meal feeding mechanisms in the palatable scheduled feeding model could focus on approaches such as neurotransmitter release.

This thesis describes the impact of high energy density nutritional supplement drinks (HENSDs) on appetite regulation, energy intake and cardiovascular risk factors in lean healthy females. It also explores the impact of Solid Ready-To-Use Foods (RTUF) and a milk based Liquid Ready-To-Use proprietary Supplement (LRUS) on weight gain and appetite in mild to moderate underweight children from Pakistan. The thesis consists of a literature review (Chapter 1), general methods (Chapter 2), three experimental chapters (Chapter 3- Chapter 5), each describing an independent research study, and a general discussion and conclusion chapter (Chapter 6). Accumulating evidence suggests that oral HENSDs increases energy intake and are beneficial for the treatment of malnutrition. Their effectiveness however, may be diminished by acute suppression of appetite. Therefore, the first experimental study aimed to investigate the extent to which the consumption of the HENSD in the fasted state reduces energy intake during a consecutive breakfast and lunch and whether this reduction relates to changes in appetite and metabolic appetite regulators. Twenty three young females with BMI of 18.2 ± 0.8 kg/m2 consumed either a HENSD or a low energy drink (PLACEBO) after fasting, in a single blind randomized cross-over study. Appetite was tracked, and blood taken, prior to the intake of the supplement and 240 minutes afterwards. Energy intake was recorded during an ad libitum buffet breakfast served 60 minutes and an ad libitum buffet lunch served 240 minutes post supplementation. Energy intake during the breakfast was significantly higher in the PLACEBO than in the HENSD trial. No significant difference was found in energy intake during the lunch between the two trials. When energy provided by supplements was added to energy intake during breakfast and lunch, the energy intake in the HENSD trial was significantly higher. The net effect was that total energy intake was increased by 1.07 ± 0.34 MJ in the HENSD trial. During the pre-breakfast, feelings of hunger and a desire to eat were significantly lower; satiety and fullness were significantly higher in the HENSD trial. After breakfast, none of the appetite measures differed between the trials regardless of plasma PYY, CCK, and insulin concentrations being significantly higher in the HENSD trial. The second experimental study investigated the time scale of compensation after HENSD supplementation. Over a five day period, energy intake was measured after the supplementation during the evening meal, and during the ad libitum breakfast, lunch and dinner consumed on the consecutive day. Since, consumption of HENSD due to the promotion of energy was expected to promote positive energy balance, this study also aimed to investigate the impact of HENSD supplementation on cardio-metabolic risk factors. Twenty-three young healthy females with a BMI of 18.7 ± 1.2 kg/m2 participated in a single blind randomised, controlled, crossover study. Participants consumed either HENSD or a PLACEBO for five days in the evening. Participants were asked to record their dietary intake during the days of supplementation. On the sixth day plasma lipids, insulin and glucose concentrations were measured in the fasted state and at 30, 60, 90 and 120 minutes after the ad libitum buffet breakfast and lunch. The findings showed that the average daily energy intake was significantly higher in HENSD trial and that consumption of HENSDs in the evening induced immediate and short-lasting reduction in energy intake. Fasting plasma concentrations of insulin and HOMA (IR) were significantly higher in the HENSD as compared to the PLACEBO trial. No significant differences were detected in fasting plasma concentrations of TAG, total-, HDL- and LDL-cholesterol between the HENSD and the PLACEBO trials. The third experimental study explored the efficacy of RTUFs and LRUS in promoting weight gain and their effect on appetite regulation in mild to moderate malnourished children. An open labelled randomized controlled trial was conducted in primary schools of Pakistan. Sixty eight mild to moderate underweight children aged 8.2 ± 1.2 years were randomly allocated to receive either RTUF or LRUS providing 500 kcal/ day in addition to regular diet in their school for four weeks. The children’s height, weight, and skinfolds were measured before supplementation and at the end of the supplementation. The children marked visual analogue scale questionnaires before the provision of the first and the last supplement. The findings from this study indicated that after four weeks of supplementation the average weight gain, change from the baseline in weight-for-age Z score (WAZ), height-for-age Z score (HAZ) in the RTUF and LRUS were not significantly different between the two groups. The difference in the appetite measures before the provision of the first and the last supplement between the two groups were also not significantly different. The total extra energy supplied for 4 weeks would have been expected to lead to an excess gain of 2kg. Thus, at least 2/3 of the energy ingested appeared to have been compensated by less intake at other times. Based on the data obtained the following conclusions have been drawn: • Following oral intake of HENSDs, the appetite suppressive action of the metabolic and hormonal appetite modulators is short lived. • HENSDs consumption for five consecutive days in the evening induced compensation, which happens immediately, disappears quickly and is short-lived which allows only partial compensation for the energy provided by HENSD. • Short-term supplementation with HENSD is safe in relation to the impact on cardiometabolic risk factors such as plasma concentration of fasting and postprandial lipids but can be expected to reduce insulin sensitivity. • RTUF and LRUS given to the community has similar impact on improving the nutritional status in mild of moderate underweight children but the overall rate of weight gain was lower than expected.

Background: Saudi Arabia is an affluent nation faced with steep population increase (~75% in just over 10 years) and a young population (63% aged under 30) in the context of globalized dietary habits and food supply leading to increase the trend of consumption junk food use. However, there are no national dietary surveys to give more accurate details. With existing high prevalence of obesity, it is foreseeable that Saudi Arabia (SA) will face a significant increase in the burden of non-communicable diseases (NCDs) in a short space of time. Reducing the behavioural and environmental risk factors associated with NCDs (physical activity, alcohol overuse, exposure to tobacco smoke, and low nutritionally balanced diet including high salt and energy intake and low intake of fruit and vegetables) requires cross-community sectors, including health, education, agriculture, and planning. Early detection and intervention also require reliable and cost effective tools. The relationship between chronic high salt intake and CVDs has already been established. This thesis examines the relationship between body composition and nutrition, and NCDs using techniques from the full breadth of Human Nutrition Research. Methods: The first cross-sectional study focused on developing and validating a culture-specific FFQ for salt intake against 24-h urinary outputs and repeated 24-h dietary recall, to identify relationships between salt intake, socio-economic factors and blood pressure (BP); and explore dietary sources of salt intake. In the second study, a secondary analysis of integrated data from five Saudi National Surveys assessed the performance of different anthropometric measures (body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and waist to height ratio (WHtR)) and body composition indices (estimated skeletal muscle mass (SMM), the percentage of skeletal muscle mass to body weight (%SMM) and Skeletal Muscle Mass Index (SMI)) in predicting metabolic diseases. Saudi nationals only were included in the study. ROC analysis was used to explore the best predictor of metabolic diseases and develop new thresholds. To assess the agreement and misclassification of overweight and obesity using BMI and WC measurements, BMI in combination with WC measurements were used to classify participants as [High-Risk Adiposity by BMI and WC], [High-Risk Adiposity by BMI only], and [High Risk Adiposity by WC only] based on the action levels. Each anthropometric and muscle mass indices were categorised to deciles. Additionally calculated were age-adjusted odds ratios by applying logistic regression models of the different metabolic risk factors in case of an increase of one decile of the respective anthropometric and estimated SMM parameter. In the third study, a cross-sectional survey was developed using the Theory of Planned Behaviour to provide a holistic understanding of factors that may influence food choices and behaviours, and in particular, intentions of adopting a nutritionally-balanced diet. External variables including age, gender, socio-economic status, and being aware of health and nutrition policies and others were included into the model as they were potentially related to TPB constructs. Attitude toward behaviour, subjective norms, perceived behavioural control and knowledge as actual barriers to behaviour were assessed. Results: In the first study, the newly developed Saudi FFQ was found to be of moderate validity in ranking people based on their estimated salt intake, and performed as well as other salt FFQ developed for other nations. The Riyadh population used in this survey consumed 8.7 g salt per day (estimate), higher than the recommended level of salt ( > 5 g/d for salt). A minority (18%) met the recommended level. The main sources of salt were, surprisingly, vegetables and un-processed foods, and a positive relationship between income and salt intake was observed. Meanwhile, salt intake, defined by FFQ, was associated with systolic BP only (R=0.089, p=0.036), an association which disappeared when adjusted for age, WC and gender. The second study highlighted that a majority of Saudi adults could be categorized as overweight or obese (72%). Worryingly, short of half of those with a normal BMI (18.5–25) aged over 45 also had a large waist. Combining WC and BMI did not improve their value as predictors of metabolic diseases and WC was the best overall predictor of metabolic diseases while BMI was the poorest. This study suggests new cut-off points for WC in SA, in a context of metabolic diseases, ranging between 90 to 92 cm (women) and 94 to 99 cm (men). The newly developed WC cut-offs are higher than the cut-offs for Asian men and women (90 and 80 cm, respectively). The new WC cut-off for women is higher than the cut-off for Caucasian women (88 cm); and the WC cut-off for men is lower than the cut-offs for Caucasian men (102 cm). The obesity prevalence based on BMI and WC also increased proportionately with both SMM (kg) and SMI (kg/m2) increase while the obesity decreased proportionately with %SMM increase. SMI was a poor predictor of metabolic diseases while %SMM was the best, having the highest AUC levels. New (defined) cut-off points for %SMM for metabolic diseases were defined, ranging from 29 to 32% for men and 26 to 28% for women. The third study highlighted that very few SA adults have been exposed to national nutrition and health guidelines (18%). Awareness of these was the strongest predictor of attitude toward behaviour, social norms and knowledge of nutritionally-balanced diet whilst perceived social pressure to engage in behaviour toward a more nutritionally balanced diet (SN) was the strongest predictor of subjects’ intention. Conclusion: Study 1 added a new and unexpected source of salt intake including vegetables and unprocessed foods. These findings raise a concern regarding the encouragement to increase intake of vegetables without including advice regarding cooking advice, in light of the risk of higher salt intake in SA. It would be worthwhile to consider education strategies towards the use of alternative ingredients or dressings in salad and cooked vegetables. Study 2 added an evidence about the weakness of BMI and SMI in predicting metabolic diseases and misclassifying the population. The study suggests using WC and %SMM as alternative measures and adopting the newly developed cut-offs. Study 3 sheds the light on possible avenues for policies, health promotions and nutrition interventions to focus on Saudi adults, in order motivate the population to adopt nutritionally balanced diet by increasing population knowledge and awareness.

Culinary herbs, the use of which has increased significantly in the last decade, are known to possess health promoting properties, which are attributed mainly to their polyphenols. However, despite the fact that such herbs undergo some form of cooking prior to consumption, there is a paucity of data concerning the effects of cooking on their properties. Furthermore, little is known of the disposition of these polyphenols following digestion and absorption, and thus it is not known whether these herbs have the potential to be significant contributors of dietary polyphenols at amounts used domestically. Thus the aim of this study was to investigate: the impact of cooking processes on the polyphenolic antioxidant activity (AA) of parsley, rosemary, sage and thyme; the impact of digestion in vitro on the AA of the herbs post cooking; the role of the gut on the AA of these herbs using the Caco-2 model of intestinal transport; and whether the AA of these herbs, contributes to their anti-inflammatory and antimicrobial activities. Results showed that cooking significantly increased the AA of these herbs. AA was further enhanced following in vitro digestion with rosmarinic acid identified as the predominant polyphenol. Polyphenolic activity was detected post absorption in vitro but, possibly due to the dilute nature of the samples used, individual polyphenols were not identified. Anti-inflammatory activity of the herbs investigated was significantly associated with their AA. However, there was no association between AA and the anti-microbial activity of aqueous extracts of herbs. Some oil extracts possessed anti-microbial activity, which was enhanced by cooking. In conclusion, this study suggests that the culinary herbs investigated have the potential to contribute to dietary polyphenol intake and thus their health promoting properties. However, the biological significance of this contribution in vivo is yet to be established.

Ischaemic stroke rates are expected to rise significantly in the next decades due to an aging population. This increases the demand for new stroke biomarkers for early detection of patients at risk and new targets for treatment. It has been hypothesized that epigenetics may be important in the aetiology of stroke. The study consisted of three types of investigation: analysis of candidate gene polymorphism, candidate gene methylation analysis and epigenome-wide methylation analysis (EWAS) of pooled stroke and control samples. The stroke types studied were large vessel disease (LVD), small vessel disease (SVD) and cardioembolic stroke (CE). DNA from peripheral blood samples was used for EWAS and methylation analysis. Significant increases in rare allele frequency were observed in the EHMT2 and DNMT3B genes for all stroke cases; MBD2, DNMT3B and DNMT3L polymorphisms were associated with LVD. IL10, SOD3, LINE1 and PITX2 were significantly hypomethylated in LVD. IL10 and ALOX15 were hypomethylated in CE compared to controls. Methylation levels of following genes were associated with age (LINE1, IL10, MTHFR, TNFα, and PITX2), gender (SOD3 and LINE1), total cholesterol level (SOD3) and systolic blood pressure (IL10). HDAC9 genetic polymorphism was associated with the MTHFR methylation level. A distinctive methylation pattern for each stroke subtype was found by EWAS. The CE pool was hypomethylated at genome, chromosome and gene level, while LVD and SVD pools had regions with higher and lower methylation levels compared to the controls. GNAS was identified as new candidate gene by EWAS. The results suggested that genetic polymorphism and DNA methylation levels of candidate genes were associated with ischaemic stroke. Stroke subtypes had distinct methylation profiles suggesting differences in underlying aetiology. Variations in methylation levels detected in this study could lead to identification of specific biomarkers. Replication on a large number of subjects is required before final conclusions can be drawn.

The endocannabinoid system (ECS) is known to be involved in key aspects of cell maintenance within the human colon, as well as being dysregulated in pathophysiological conditions, including colon inflammation and cancer. However, the contribution of the ECS within each of these conditions has not been fully elucidated. This indicates that the current identification of key targets within the ECS that are involved in gut pathology could be used as potential novel therapeutics. Two experimental approaches were designed and optimised to give an insight into ECS signal regulation within the human colon and to screen ECS therapeutics, tetrahydrocannabinol (THC) and cannabidiol (CBD); a human colon ex vivo explant culture model and an innovative multiplexed quantitative gene expression technology, the GenomeLab GeXP system (Beckman Coulter). Gene targets were identified that are known markers of regulation and function in cells of healthy tissue. An assay, the hCellMarkerPlex was designed that incorporated twenty-three of these gene targets, epithelial (EZR, KRT18, SLC9A2), proliferation (PCNA, CCND1, MS4A12), differentiation (B4GANLT2, CDX1, CDX2), apoptotic (CASP3, NOX1, NTN1), fibroblast (FSP1, COL1A1), structural (ACTG2, CNN1, DES), gene transcription (HDAC1), stem cell (LGR5), endothelial (VWF) and mucin production (MUC2). The hCellMarkerPlex identified gene signatures which distinguished between normal, adenoma and carcinoma tissue, identifying cellular processes showing abnormal activity associated with pathological status. The resulting biomarker profiles were used to establish a human colon explant culture system. The human colon explant culture presents a novel model to study modulation of the ECS and screen ECS therapeutics. Combined with the GenomeLab GeXP System multiple components of the ECS were assessed at the gene regulatory level. A custom designed GeXP assay, the hECSplex, was developed. hECSplex gene expression signatures of EC receptors (CNR1, CNR2, GPR55 and TRPV1), ECS enzymes (NAPE-PLD, GDE1, DAGLA, DAGLB, FAAH, FAAH2 and PTGS2), inflammatory (IL1B, IL10, IL6, LEP, TNF and SOCS3), signalling pathway (ID1, BCL2, CFL1, BIRC5, TP53, MYC and KRAS), lipid production (SREBF1, ACACA), and plasma-membrane (OCLN) markers revealed altered expression of ECS components in carcinogenesis compared to normal tissue. Abstract vi . The hECSplex gene expression signature of colon explants showed that ECS was not altered during culture, emphasising the explant models capability as a pharmaceutical tool to test current and novel therapeutics. Applications of both THC and CBD to normal colon explants at different concentrations do not lead to any significant changes. Indicating the current pharmacological use of phytocannabinoids is causing no adverse effects in surrounding healthy colon tissue. The GenomeLab System presents new opportunities to interrogate multiple components of the endocannabinoid signalling system in small colon explant tissue samples, and in response to ECS therapeutics.

Understanding the complex linkage between obesity and food choice is pivotal to establishing effective dietary guidance that resonates with consumers. The aims of this thesis were to evaluate: (1) serving size (SS) guidance schemes and their effectiveness; (2) consumer estimations of portion size (PS) and energy density (ED), and anticipated consumption guilt (ACG) for perceived 'healthier' vs. 'standard' foods; (3) consumer opinions, perceptions of efficacy and the precision of a range of portion size estimation aids (PSEA); and (4) the nutritional quality (NQ) and energy cost (EC) of own brand (OB) vs. market brand (MB) foods. A literature review and three studies were undertaken. In the first study, three pairs of isoenergy dense (kJIlOOg) foods - 'healthier' vs. 'standard' cereals, drinks and coleslaws - were selected. For each food, subjects (n186) served an appropriate PS for themselves, estimated its ED and rated their ACG. Subjects estimated larger portions of the ' healthier' (reduced fat) coleslaw than the 'standard' version, and perceived all 'healthier' foods to be lower in ED than their 'standard' alternatives, despite being isoenergy dense. Higher ACG was associated with the 'standard' foods . In the second study, a range of PSEA were evaluated using both qualitative (six focus groups, each of three to eight participants) and quantitative (practical use of PSEA; n 120) methods. Consumers indicated preference for "visual" PSEA (reference objects, household measures e.g. cup, and indicators on food packaging) for amorphous cereal products such as rice. In the third study, a basket of commonly consumed foods (n 32) were compared in terms of NQ and EC at two time points using two methods of nutritional profiling. Despite OB foods being significantly lower in EC (£/MJ) than the MB, there were no differences in the overall NQ. In conclusion, consumer understanding of PS, perceptions of ED and preferences for PSEA should be considered in future dietary guidance. OB foods should be promoted as nutritionally comparable to their more expensive MB counterparts where appropriate.

No description available.

The imidazole dipeptides (ImD); anserine (Ans), carnosine (Cam) and balenine, have been shown to be effective at functioning as H+ ion buffers, with Carn being particularly effective within the physiological pH range. Therefore ImD have been reported to be beneficial to athletes exercising at high intensities, where the activity results in the production and accumulation of H+ ions within skeletal muscle. It has also been hypothesised that these compounds may also be beneficial in reducing the morbidities related to ageing, such as Alzheimer's disease. Humans store ImD in the form of Carn and not as anserine or balenine. However, within the human body Carn production is limited by the ability to degrade uracil in the liver, with 3-alanine being the limiting factor. Therefore the content of the diet has a substantial impact on the level of Carn within human skeletal muscle. This thesis aimed to investigate the variability in ImD with age and in subjects from different geographical locations. The effect of ageing on the muscle content of the ImD was demonstrated through the use of a murine model, where increased age was accompanied with a 45% decline in the ImD levels measured in the tibialis anterior of 60wk old senescence-accelerated male mice (Chapter 9). This is supported by further work (Chapter 14) which showed that elderly European subjects exhibited lower levels of carnosine in the vastus lateralis compared to younger European subjects (15.6mmol·kg-1 dm and 22.4mmol·kg-1 dm respectively). However, in Korean elderly subjects no decline was observed (21.5mmol·kg-1 dm), and this could potentially be explained by different dietary habits, with the elderly Korean subjects consuming larger amounts of protein-rich foods than their European counterparts. Analysis was made of the variation in the carnosine content of the vastus lateralis in subjects from differing geographical locations, and subsequently different cultural diets with varying meat contents, and showed that dietary intake of a diet habitually rich in the ImD could potentially 'over-ride' the decline seen with age in subjects who 'reduce' their meat intake.