Tesi sul tema "Carbohydrates in human nutrition"

1. This series of studies was undertaken to examine the adrenergic regulation of carbohydrate metabolism during exercise. Recreationally active males were tested during moderate to intense exercise on a stationary cycle ergometer. Venous and arterial plasma obtained from indwelling catheters was analysed for hormonal and metabolite responses, and hepatic glucose production and glucose uptake were measured using the tracer-dilution method with stable isotopes. Muscle samples were obtained by the needle biopsy technique to examine muscle glycogen utilisation and the flux of related muscle metabolites using enzymatic, fluorometric and radioisotopic techniques. 2. During moderate exercise adrenaline infusion induced a marked hyperglycemia and this was due to reduced glucose uptake rather than enhanced hepatic glucose production. The reduction in glucose uptake was most likely mediated by a decrease in glucose phosphorylation, as indicated by the accumulation of glucose 6-phosphate with adrenaline infusion. 3. The hyperglycemic response to intense exercise was prevented by the administration of α- and β-adrenergic antagonists. Adrenergic blockade was without effect on hepatic glucose production whereas glucose uptake was enhanced when compared with control subjects. These data support the notion that adrenergic mechanisms are more important in restraining glucose uptake than enhancing hepatic glucose production during intense exercise. Other glucoregulatory factors are responsible for the increase in glucose production during intense exercise. 4. Elevated plasma adrenaline levels during moderate exercise in untrained men increases skeletal muscle glycogen breakdown and PDH activation which results

[Truncated abstract] Obesity is now a major public health problem worldwide. More than half the Australian population is now overweight. This is an important public health concern primarily because of the impact of overweight and obesity on risk of diabetes, hypertension and cardiovascular disease. Many strategies have been proposed to fight the obesity epidemic. One possible strategy involves understanding of the role of dietary components in the control of food intake. In this regard, dietary protein and fibre appear to be the most satiating nutrients. Foods enriched in protein, replacing energy from carbohydrate, or dietary fibre can increase satiety and reduce energy intake in the short-term. Longer-term trials suggest benefits of increasing protein or fibre intake on weight loss and features of the metabolic syndrome. The effects of dietary approaches which increase both protein and fibre at the expense of refined carbohydrate are uncertain. A practical approach to increasing both protein and fibre content of processed foods is to incorporate high protein and fibre ingredients into high carbohydrate foods. Lupin kernel flour is a novel food ingredient derived from the endosperm of lupin. It contains 40 to 45% protein, 25 to 30% fibre, and negligible sugar and starch. Lupin kernel flour can be incorporated into refined carbohydrate rich foods such as bread to increase protein and fibre content at the expense of refined carbohydrate. ... Body weight was measured every 2 weeks throughout the 16 week intervention, and these data were analysed to determine whether there was any between group difference in the rate of change in weight over 16 weeks. Over 16 weeks, lupin bread compared to white bread resulted in a significant increase in protein (13.7 (2.3, 25.0) g/d) and fibre (12.5 (8.8, 16.2) g/d) intakes, and a decrease in carbohydrate intake (-19.9 (-45.2, 5.5) g/d). There was a significant difference between groups in the rate of weight change over the 16 weeks (P=0.05). However, at 16 weeks there was no significant effect on body weight (-0.4 (-1.3, 0.6) kg), fat mass (-0.5 (-1.2, 0.2) kg) or fat free mass (0.2 (-0.5, 0.8) kg). Plasma adiponectin and leptin were not altered. Mean 24 hour systolic blood pressure (-2.4 (-3.4, -1.3) mm Hg) and pulse pressure (-3.1 (-3.9, -2.3) mm Hg) were lower for lupin relative to white bread, but diastolic blood pressure was not significantly different between groups. Apart from a lower HDL cholesterol for lupin relative to white bread (-0.09 (-0.17, -0.01) mmol/L), there were no significant differences in other blood lipids and glucose and insulin concentrations. Interpretation of the results was not influenced after adjustment for potential confounding factors. These studies assessed effects of bread enriched in lupin kernel flour relative to white bread, resulting in a higher protein and fibre intake and lower refined carbohydrate intake. This increased satiety and reduced energy intake acutely, but did not significantly influence body weight over 16 weeks. Systolic blood pressure and pulse pressure were significantly reduced. There were no significant improvements in blood lipids or glucose and insulin concentrations. Therefore, increasing protein and fibre intake at the expense of refined carbohydrate using lupin kernel flour may benefit satiety and blood pressure. Longer-term trials incorporating weight loss may be needed to observe benefits on body weight.

The prevalence of diabetes and other pathophysiological conditions has been correlated with the incidence of obesity. A large portion of an adult community in the northwestern United States suffers from excessive weight that has been linked to premature mortality rates and certain forms of diabetes. Excess calories from carbohydrate have been shown to increase weight. Therefore, diets that are modified in carbohydrate and calories may help mitigate weight and obesity comorbidities. This qualitative, single case study's purpose was to explore the methods health care professionals use for teaching adults about controlling weight. Altheide and Johnson's analytic realism theory, in which they describe how the experiences of educators and learners affect the way information is perceived, formed the conceptual framework for this study. An illustrative case study paradigm was used to identify the perceptions of licensed health care practitioners regarding the current adult teaching methods for modifying dietary carbohydrate and excess weight. Using a purposeful sample, data were collected in 2 phases with 5 licensed health care practitioners: Phase 1 entailed an open-ended electronic questionnaire and semistructured telephone interviews with open-ended questions during phase 2. Data were analyzed through coding and aggregation by NVivo and Tosmana software, respectively. The findings indicated that the American Diabetes Association (ADA) plate method was the most effective teaching model for controlling weight and carbohydrate intake. Consequently, the ADA plate method was used to create a professional development program to teach health care educators about nutrition instruction methods for adults. The study contributes to positive social change by enhancing preventive health measures for the local adult population through diet therapy education.

Weight gain due to poor diet and lack of exercise is responsible for over 300,000 deaths each year (U.S. Department of Health and Human Services, 2010). Obese adults have an increased risk for serious health conditions including high blood pressure and cholesterol, type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, sleep apnea, respiratory problems, and certain cancers (National Cancer Institute, 2012). Participation in exercise can help control weight, strengthen muscles and bones, and reduce the incidence of cardiac events, stroke, hypertension, type 2 diabetes, colon and breast cancers, osteoporotic fractures, gallbladder disease, obesity, depression, anxiety, and delay mortality (ACSM, 2009). The purpose of this study was to determine the effectiveness of exercise participation during weight loss on a high protein-low carbohydrate diet plan during a 12-week span in females aged 15 to 25 years. Specifically, this research study was a comparison of markers of health such as weight, fat mass, percent body fat, and fat-free mass in females who consistently exercised during the diet (Exercisers) from those who did not participate in consistent exercise (Non- Exercisers). The population in this study was selected due to the transition from high school to college being a critical period because it is associated with many identity choices and lifestyle changes that can lead to weight gain (Anderson, Shapiro, & Lundgren, 2003). The data indicate participation in regular exercise, while consuming a high protein-low carbohydrate diet plan, increases the loss of body weight, fat mass, and percent body fat when compared to participating in the diet plan alone. There was no significant difference in fat-free mass reduction between the groups. One implication for practice is recommending moderate to vigorous exercise for a minimum of 30 minutes at a time, totaling a minimum of 150 minutes per week, for females trying to achieve weight loss. Based from the results of this research study, in order to achieve a greater amount of body weight, fat mass, and percent body fat reduction one should consider incorporating exercise participation and high protein-low carbohydrate dieting into their weight loss plan.

Four studies were conducted using high water soluble carbohydrate (WSC), sweet (SM) and low WSC, regular (RM) pearl millet and high WSC (SS) and low WSC (RS) sorghum cultivars. The first and the second studies evaluated the chemical composition and ensiling characteristics of those cultivars. Millet cultivar had no effect on pH. SM silage contained less neutral and acid detergent fiber than RM silage. SS cultivar had less pH than RS cultivar at any ensiling period. RS silage contained greater acid detergent lignin and less non protein nitrogen than SS silage. The third and the fourth studies investigated the feeding value of SM and SS silages. Cows fed SM silage produced milk with greater fat concentration, energy corrected milk, 4% fat corrected milk, and solid corrected milk yield than cows fed corn silage. Milk fat was greater, while milk yield and lactose concentration were less for cows fed SS silage than cows fed alfalfa silage. In conclusion, there is a good potential for pearl millet silage as a source of forage for dairy cows. Further investigations are required to optimize the feeding value of sorghum silage.
Quatre études ont été conduites utilisant deux variétés de millet perlé [i.e. riches en glucides solubles (GS) (MS) et pauvre en GS (MR)] ainsi que deux variétés de sorgho [i.e. riches en GS (SS) et pauvre en GS (SR)]. Les première et deuxième études évaluèrent la composition chimique et les caractéristiques d'ensilage des différentes variétés. La variété de millet n'eut pas d'effet sur le pH. L'ensilage de MS contenait moins de fibre NDF et ADF que l'ensilage de MR. La variété de SS avait un pH inférieur au SR à tout moment lors de la période d'ensilage. L'ensilage de SR contenait une quantité supérieure de lignine et moins d'azote non protéique que l'ensilage de SS. Les troisième et quatrième études investiguèrent la valeur nutritive des ensilages de MS et SS. Les vaches soignées à l'ensilage de MS ont produit du lait plus concentré en gras, énergie du lait corrigée, 4% gras du lait corrigé et rendement en solides du lait corrigé que les vaches soignées à l'ensilage de maïs. La concentration en gras du lait était la même tandis que le rendement en lait et la concentration en lactose furent inférieurs pour les vaches soignées à l'ensilage de SS comparativement à celle soignées à l'ensilage de luzerne. En conclusion, il y a un grand potentiel pour l'ensilage de millet perlé en tant que source de fourrage pour les vaches laitières. D'autres études seraient nécessaires pour optimiser les valeurs nutritives de l'ensilage de sorgho.

Mayer's Glucostatic Theory of appetite regulation has been a precursor for many studies in this field. No studies have applied this model to extreme fluctuations of blood glucose. The present study examined if Mayer's theory holds true with carbohydrate (CHO) loading and reduction in healthy men. Six normal weight, healthy men (23.8 +/- 1.3 kg/m2) participated in a randomized crossover trial. Three day eucaloric diet conditions (75% CHO, 45% CHO, and 10% CHO) preceded a 10 h testing day in the lab where blood glucose measured every 5 min for 9 h. with appetite ratings measured every 30 min. Food was available upon request; hunger, intake and food preference were measured. No differences in daily energy intake (EI), blood glucose and appetite were noted between conditions. In all subjects during all phases, blood glucose levels decreased by 7.8+/- 11.1% prior to meal requests. Meal requests were preceded by declines in blood glucose but changes in appetite, EI and CHO preference were not seen. Key words: Glucostatic Theory, appetite, blood glucose, hunger, feeding, carbohydrates

Conoscenze preesistenti: Le transglutaminasi (TGase) sono una classe di enzimi ampiamente diffusa tra gli organismi procarioti ed eucarioti. Gli enzimi di questa famiglia catalizzano modifiche post-traduzionali in molte proteine attraverso reazioni di trasferimento dell’acile, reazioni di deaminazione e di crosslinking (polimerizzazione) tra residui peptidici di lisina (accettore di acile) e glutammina (donatore di acile) intra- o inter-catena proteica. A causa della sua facilità di espressione e di purificazione, l’unica TGase ampiamente usata per le applicazioni industriali è la TGase microbica estratta da Streptomyces mobaraensis (MTGase). Oggigiorno la MTGase è disponibile in commercio ed è ampiamente usata nell’industria dei biopolimeri, in cosmetica, per applicazioni cliniche, nell’industria tessile della lana e soprattutto nell’industria alimentare. La sua abilità di catalizzare legami crociati in molti substrati proteici differenti è sempre più usata non solo per la produzione di salsicce, prosciutti e formaggi ma, molto recentemente, anche per la detossificazione della farina, come possibile terapia alternativa alla dieta senza glutine. Ne consegue che oggigiorno le applicazioni industriali della MTGase stiano aumentando, coinvolgendo sempre più settori e producendo una ricerca scientifica su questo argomento sempre più fervente, allo scopo di tentare di rispondere a specifiche esigenze industriali, come l’implementazione di sistemi di purificazione della MTGase più efficienti, la ricerca di fonti alternative di transglutaminasi microbica, e di fonti sicure di enzimi ricombinanti. Scopo del progetto di dottorato: lo scopo principale del progetto è l’identificazione di nuove forme di transglutaminasi microbica che possano diventare un’alternativa a quella attualmente in uso. È stata eseguita un’analisi approfondita delle sequenze note allo scopo di ottenere una classificazione delle TGase microbiche attraverso la loro similarità a forme note. Per selezionare le migliori candidate che possano essere forme attive in appropriate condizioni, le sequenze selezionate sono state soggette di modellamento molecolare e simulazioni molecolari. Per testare l’attività enzimatica, sono stati effettuati dei saggi sperimentali su una nuova forma trovata ed un’ulteriore nuova forma è stata espressa. Risultati: il presente lavoro propone in primo luogo un’analisi, ad oggi assente, dell’ampio panorama delle transglutaminasi microbiche, sviluppando la prima classificazione delle TGase microbiche basata sulle loro caratteristiche di sequenza e sulle loro specifiche strutture secondarie predette. Al fine di classificare ed analizzare le caratteristiche strutturali di tutte le sequenze annotate come aventi un TGase core, sono state utilizzate tecniche computazionali che coinvolgono analisi di sequenza, studi comparativi, costruzione di alberi filogenetici, modellamento per omologia e simulazioni di dinamica molecolare. Tramite questo approccio, è stata effettuata una classificazione preliminare di queste sequenze dividendole in cinque gruppi principali. Ogni gruppo è stato studiato dal punto di vista delle sequenze per analizzare la presenza di motifs specifici. Per tre di questi cinque gruppi, sono state studiate anche le strutture secondarie e, da questa analisi, sono state rilevate caratteristiche specifiche per ogni gruppo. Inoltre, due nuove forme di TGase microbica (mTGase) sono state studiate in dettaglio: K. albida mTGase e l’ipotetica mTGase da SaNDy (organismo non rivelato per possibilità di brevetto). Per la prima, in comparazione con la MTGase, sono state effettuate analisi della tasca relativa al sito attivo e simulazioni di dinamica molecolare. Per la seconda, invece, sono state utilizzate tecniche sperimentali per purificare l’ipotetico enzima al fine di testarne l’attività su substrati alimentari. Saggi sperimentali su entrambe le proteine sono ancora in corso, al fine di trovare le migliori condizioni di attività enzimatica e i migliori substrati di reazione. Le simulazioni di dinamica molecolare eseguite sulla mTGase di K. albida hanno suggerito alcune spiegazioni alla maggiore specificità di questo enzima rispetto alla MTGase, dimostrata sperimentalmente da Steffan e colleghi, ed alcune indicazioni per variare le condizioni di attività usate per testarla. Inoltre, l’analisi dei substrati ha permesso di trovare nuovi possibili substrati, sui quali l’enzima potrebbe essere impiegato ai fini della riduzione delle allergenicità. D’altro canto, l’enzima estratto da SaNDy, mostrando una più alta somiglianza con la MTGase, potrebbe essere meno selettivo della mTGase da K. albida nei confronti di specifici substrati, pertanto potrebbe essere possibile una sua applicazione anche su substrati gliadinici, tuttavia, per provare ciò, sono necessari ulteriori esperimenti. Note: il presente lavoro di dottorato è stato principalmente svolto presso il Laboratorio di Bioinformatica del CNR di Avellino sotto la supervisione del Dr. Facchiano, tuttavia, tutte le simulazioni di dinamica molecolare sono state eseguite presso il Dipartimento di Biochimica dell’Università di Zurigo, nel laboratorio di biologia strutturale e computazionale sotto la supervisione del Prof. A. Caflisch e del suo gruppo di ricerca (periodo di formazione all’estero obbligatorio). I saggi di attività sperimentale sul substrato gliadinico sono stati effettuati dal laboratorio di spettrometria di massa CeSMA-ProBio presso il CNR di Avellino; e l’ipotetica mTGase da SaNDy è stata invece clonata, espressa e purificata durante la collaborazione con il laboratorio di Molecular Sensing presso il CNR of Avellino.
Background: transglutaminases (TGase) are a class of enzymes widely spread in eukaryotic and prokaryotic organisms. Enzymes of this family catalyze post-translational modifications in many proteins by acyl transfer reactions, deamidation and crosslinking (polymerisation) between protein intra- or inter-chain glutamine (acyl donor) and lysine (acyl acceptor) peptide residues. Due to its facility of expression and purification, the only TGase enzyme widely used for industrial applications is the microbial TGase extracted from Streptomyces mobaraensis (MTGase). Nowadays the MTGase is commercially available and widely used in biopolymers industry, in cosmetics, in clinical applications, in wool textiles, and above all in the food processing industry. Its ability to catalyze crosslinks on many different protein substrates is increasingly used not only for sausage, ham and cheese production but, very recently, also for flour detoxification, as a possible alternative therapy to the gluten free diet. It follows that nowadays the industrial applications of MTGase have increased, covering more and more fields producing a very active scientific research about this topic aimed at attempt to meet specific industrial needs, as the implementation of more efficient system for MTGase production, the research of alternative sources of microbial TGase, and safe source of recombinant enzymes. Aims of the doctorate project: the main aim of the project is the identification of novel forms of microbial TGases that could become an alternative to that in use. A depth screening of known sequences has been performed, with the aim of obtaining a classification of microbial TGases for their similarity to known forms. To select the best candidates to be active forms under appropriate conditions, molecular modelling and molecular simulations have been performed on selected sequences. To test the enzymatic activity, experimental assays have been performed with a novel form, and another novel form has been expressed. Results: the present work proposes at first an analysis, lacking so far, of the wide microbial transglutaminase world, developing the first classification of the microbial TGase based on their sequence features and their specific predicted secondary structures. In order to classify and analyze the structural features of all the sequences annotated as having a TGase core computational techniques involving sequence analyses, comparative studies, building of phylogenetic trees, homology models and molecular dynamic simulations have been used. From this approach, a preliminary classification of these sequences was done by dividing them in five main groups. Each group has been investigated from the sequence point of view to analyze the presence of specific motifs. For three of this five groups, also the secondary structures have been investigated and, from this analysis, features specific for each group have been detected. Moreover, two novel forms of microbial TGase (mTGase) have been investigated in the detail: K. albida mTGase and the hypothetical mTGase from SaNDy (organism not disclosed for patent opportunity). Molecular dynamics simulations and active site pocket analyses have been performed for the first, in comparison with MTGase. For the second, instead, experimental technique has been used to purify the hypothetical enzyme in order to test it on food related substrates. Experimental assays on both the proteins are still ongoing, to find the best enzymatic activity conditions and the best substrates of reaction. The molecular dynamic simulations performed on K. albida mTGase have suggested some explanations to the higher specificity of this enzyme than MTGase, experimentally demonstrated by Steffen et colleague, and several indications to change the activity conditions used to test it. Moreover, the substrates screening has allowed to find novel possible substrates, on which this enzyme could be employed for the allergenicity reduction. On the other hand, the enzyme extracted from SaNDy, showing a higher similarity with MTGase, could be less selective than K. albida mTGase for specific substrates, so it could be possible its application also on the gliadin substrate, but to prove it further experiments are necessary. Note: the present PhD work has been mainly performed in the Bioinformatics Laboratory at the CNR of Avellino under Dr. Facchiano’s supervision, however all the MD simulations have been performed at the Biochemistry Department of the University of Zurich, in the computational and structural biology laboratory under the supervision of Prof. A. Caflisch and his research group (compulsory abroad training period). Experimental activity assays on gliadin substrate have been performed by the spectrometry mass CeSMA-ProBio lab at the CNR of Avellino; and the hypothetical mTGase from SaNDy was instead cloned, expressed and purified in collaboration with the Laboratory for Molecular Sensing at the CNR of Avellino.

The dietary recommendation to replace saturated fat with carbohydrate as a means of reducing cardiovascular risk, has been hindered by the adverse effect of dietary extrinsic sugars on plasma lipids. The project described in this thesis, formed part of a BBSRC- funded trial to examine the impact of dietary extrinsic sugars on lipoprotein kinetics. A key objective of this project was to design and deliver two diets, high and low in extrinsic sugars, to test the hypothesis of the main trial; that dietary sugars influence plasma lipids, via differential effects on the kinetics of plasma lipoproteins, in groups with moderately raised and low liver fat. This thesis presents the results from five experimental Chapters (2-6): i) An independent, systematic review and meta-analysis of the relationship between dietary sugars and plasma lipids (Chapter 2), that confirmed significant positive and negative associations between dietary sugars, especially fructose, with plasma TAG and HDL-cholesterol, respectively; ii) the development of two experimental diets, high and low in sugars, based on the exchange of starch and sugars, using supermarket foods (Chapter 3). The exchange achieved, and came crose to achieving, target intakes for sugar, that were representative of the upper 95th and lower 5th percentile of sugar intake in the UK; iii) a study of the impact of these two diets on plasma lipids and lipoproteins, in groups with raised and low liver fat (Chapters 4 & 5). The high sugar diet was accompanied by significant increases in plasma TAG, apoproteins (CIII & E), and liver fat, and decreases in HOL-choiesterol, and lipoprotein particle size. In contrast, the low sugar diet was associated with opposite changes in all of these variables. The effects of both diets were shown to be more pronounced in the group with moderately raised liver fat (> 4.2%), and were largely unaltered by the re-analys is of sugar intake by three different methods (Chapter 6). These findings provide evidence for the practical feasibility, and experimental utility of exchanging starch and sugars in real foods. They also provide further support for the recommendation to restrict the intake of dietary extrinsic sugars, especially in individuals with moderately raised liver fat.

Aim of this thesis was to evaluate mixtures of indigestible carbohydrates in vitro to predict their effects on gut function. In this study, I investigate the effect of combining carbohydrates with different fermentative properties and their interactive influences, reflected in the end products from in vitro fermentation. The study focused on the rate of fermentation and fermentability of such mixtures and the SCFA produced to gain an index of the likely site of fermentation in the colon. The main aim of the thesis was to produce a mixture of carbohydrates which would delay but preserve butyrate production from rapidly fermenting carbohydrates such as raftilose. This was achieved in several mixtures but mostly those containing raftilose and ispaghula. In general, mixtures of carbohydrates were fermented more slowly than raftilose alone. Overall, ispaghula was the most effective in slowing the rate of fermentation compared with pectin or gums. Mixing raftilose with ispaghula or guar gum gave the best preservation of n-butyrate and propionate production. The rate of n-butyrate production was less rapid in mixed cultures of three carbohydrates (raftilose, ispaghula and pectin) than cultures of 100mg raftilose but production of n-butyrate was preserved. In summary, ispaghula and raftilose in two-carbohydrate mixtures and ispaghula, pectin and raftilose in three-carbohydrate mixtures delayed the release of butyrate with no loss in butyrate production and may move butyrate further round the colon, at the same time reducing the potential adverse effects of raftilose. Moreover, the addition of pectin (or guar gum) may add the therapeutic effect of delaying nutrient absorption in the small intestine was well. These studies have identified at least two mixtures (raftilose & ispaghula; raftilose, ispaghula & pectin) worthy of study in more detail in man.

In an attempt to determine the extent to which well-trained endurance athletes practice the dietary recommendations for maximizing muscle glycogen resynthesis, twenty-four collegiate cross-country runners (14 males and 10 females) were chosen as subjects. The athletes kept four-day food and activity records during both a training and competitive period in the regular season. Energy intake was shown to be adequate in both phases. Total calories from carbohydrate, primarily complex, were found to be inadequate (<60%) for male runners and desirable (>60%) for females. Approximately 50% or less of the time carbohydrate was ingested immediately post-exercise, with even far less taken in suggested quantities (-1 g CHO/kg body weight). While the male athletes consumed primarily a combined solid and liquid form of carbohydrate immediately post-exercise, the females chose solid sources. Cereals and other breads were the most popular types of carbohydrate chosen immediately following exercise, in addition to commercial sports drinks/bars which were frequently ingested. An even more unfavorable trend in the distance runners was the infrequency of additional carbohydrate being ingested at two hour intervals following exercise. There were no significant differences in dietary trends between training and competitive phases. Overall these endurance athletes were not practicing the recommended feeding regimen for optimal muscle glycogen restoration.
Department of Home Economics

The folates are a family of structurally similar, water-soluble, B vitamins, documented to play prominently in human health and disease. The potential impact of folate nutrition has been demonstrated by large-scale epidemiological and nutritional studies indicating that decreased folate intake increases the risk of cancer development. Human skin is particularly prone to the development of carcinomas and it is established that skin cancer risk correlates with exposure to the complete carcinogen ultraviolet radiation (UVR) in the form of sunlight. Recently a link between skin, sunlight, and folate has emerged from studies demonstrating that folate species are degraded by exposure to wavelengths of UVR contained within the solar spectrum. It is hypothesized that the unique physiology, function, and environment of skin combine to make skin tissue prone to folate deficiencies and that folate supplementation is a promising strategy for the prevention of skin cancer. However, many questions regarding folate nutrition within human skin must be answered before strategies to modulate folate nutrition may be rationally designed and safely implemented. This work presents novel means to examine skin-specific folate nutrition, including an analytical method to quantify individual folate species in human keratinocytes adaptable for the analysis of intact skin tissue and innovative cultured keratinocyte models of both acute and chronic folate deficiencies. It is demonstrated that folate deficiencies in skin tissue are possible and even likely as proliferating human keratinocytes are unable to maintain intracellular folate concentrations when nutrient conditions are limited and exposure to UVR results in biologically relevant folate degradation. Folate deficiency in human keratinocytes is observed to have potential pro-carcinogenic consequences including S-phase proliferation arrest, increased inherent DNA strand breaks, increased uracil misincorporation into DNA, and deficiencies in DNA damage repair, which are reversed when folate nutrient levels are optimized. The presented work characterizes the relationship between intracellular folate species and environmental carcinogens known to induce skin cancer and addresses challenges facing supplementation strategies for specifically improving folate nutriture in human skin. In total, this report broadens our understanding of folate nutrition in human skin and demonstrates that optimization of folate nutrition holds promise as a cancer preventive strategy.

Purpose: To determine the effect of four postexercise beverages, differing in macronutrient content, on metabolic response to an acute resistance exercise bout.

Methods: Forty male subjects performed five sets of eight repetitions at 80% 1RM for leg press and leg extension, and then consumed one of four postexercise beverages (Placebo, PL: a carbohydrate-electrolyte beverage, CE; or one of two milk-based beverages, MILK 1: 1% chocolate milk; MILK 2: a high protein milk beverage). Indicators of muscle protein synthesis (MPS) were assessed before and 1-hr after consuming a postexercise beverage. Muscle protein degradation (MPD) was examined the day before and the day of exercise.

Results: No significant differences were found among groups in MPS. The resistance exercise bout increased the amount of eIF4E-eIF4G by 4.5% 1-hr postexercise (p<0.05) without affecting the amount of eIF4E-4E-BP1. One hour after beverage consumption, serum total amino acid concentration increased for MILK 1 (p=0.003) and MILK 2 (p<0.001) but decreased for CE (p=0.028) and PL (p=0.276). Consumption of MILK 1, MILK 2, and CE significantly increased circulating levels of serum insulin (p<0.001). Serum growth hormone increased 3-fold as a result of the exercise bout but fell to baseline for all groups by 60 min (p<0.001).

Conclusion: The resistance exercise bout was anabolic as shown by the increase in the active eIF4E-eIF4G complex and serum growth hormone. Consumption of MILK 2 led to the most optimal environment for muscle anabolism; however, none of the experimental beverages influenced the measured indicators of muscle protein translation 1-hr after ingestion.
Master of Science

Thesis (MNutr)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Introduction and purpose The aim of the study was to determine the renal handling of a once-off bolus dietary protein load in patients treated for nephroblastoma. Patients who have been managed for nephroblastoma always have suboptimal amounts of kidney tissue as a result of their medical management which includes nephrectomies, chemotherapy and or radiotherapy. Little data are available indicating the extent of renal impairment expected in such patients as a result of their disease and management. The study was to determine whether the use of regular screening tests such as serum urea, creatinine and urine microalbumin, in conjunction with a dietary protein load could help detect early progressive deterioration of kidney function in nephroblastoma patients. Methodology The study was a quantitative non-randomised intervention study in which patients served as their own control before and after a protein load. Thirty-four participants were included in the study. Each participant was provided with a supplemental protein drink providing 2 g/kg body weight of protein. Serum creatinine, urea and urine microalbumin were assessed at baseline and four hours after the intervention. These pre- and post intervention biochemical values were then analysed together with descriptive data relating to the participants, such as age, stage of nephroblastoma, aspects of medical management and the period of time since they had been treated for nephroblastoma, and statistical relationships were assessed. Data were collected from May 2010 to November 2010. Results Descriptive statistics indicated that the mean [± Standard deviation (SD)] age of the population was 92 (± 55) months, the mean age at diagnosis was 41 (± 27) months and the mean age from the diagnosis to the time of the study was 51 (± 53) months. There was a statistically significant increase (p = 0.00) in serum urea post intervention; however, no significant difference was noted between pre- and post intervention serum creatinine and urine microalbumin values. The stages of nephroblastoma failed to show a statistical correlation with the response to the dietary protein bolus load in terms of the difference in pre- and post intervention biochemical data. No statistical correlation was found between post-pubescence and response to the protein load. Similiarly, no statistical correlation could be demonstrated for a longer period between the diagnosis and the time of this study, on the one hand, and the prevalence of high values in the biochemical data, on the other. Conclusion The study was unable to demonstrate statistically that participants managed for nephroblastoma had poor renal handling of a once-off dietary protein load in terms of the objectives specified. The study had limitations including a small population with even smaller subgroups of participants, therefore results of the study need to be interpreted in context to the size of the population.
AFRIKAANSE OPSOMMING: Doel Die doel van die studie was om die renale hantering van ’n eenmalige bolus dieetproteïenlading by pasiënte wat vir nefroblastoom behandel word, te bepaal. Pasiënte wat vir nefroblastoom behandel word, het altyd ‘n subopitmale hoeveelheid nierweefsel as gevolg van hulle mediese behandeling wat nefrektomies, chemoterapie en / of radioterapie insluit. Min data is beskikbaar omtrent die omvang van die nierbelemmering wat in sulke pasiënte verwag word as gevolg van hulle siekte en behandeling. Die studie is uitgevoer om te bepaal of die gebruik van gereelde siftingstoetse soos serum-ureum, kreatinien en mikroalbuminurie, in samewerking met ‘n dieetproteïenlading, kan help om vroeë progressiewe agteruitgang van nierfunksie in nefroblastoom pasiënte, op te spoor. Metodologie Die studie was ‘n kwantitatiewe nie-ewekansige intervensie studie waar pasiënte as hul eie kontrole gedien het voor en na ‘n proteïenlading. Altesaam 34 deelnemers is by die studie betrek. Elke deelnemer het ’n proteïenaanvullingsdrankie ontvang wat 2 gram proteïen per kilogram liggaamsgewig voorsien het. Serumkreatinien, serum-ureum en mikro-albuminurie is op die basislyn sowel as vier uur na die intervensie gemeet. Hierdie biochemiese waardes voor en na die intervensie is daarna saam met beskrywende data van die deelnemers – soos ouderdom, stadium van nefroblastoom, aspekte van mediese behandeling en tydsverloop sedert behandeling vir nefroblastoom – ontleed. Statistiese verwantskappe is vervolgens beoordeel. Data is vanaf Mei 2010 tot November 2010 ingesamel. Resultate Beskrywende statistieke het op ’n gemiddelde [± Standaard afwyking (SA)] populasie-ouderdom van 92 (± 55) maande, ’n gemiddelde diagnose-ouderdom van 41(± 27) maande en ’n gemiddelde ouderdom van 51(± 53) maande vanaf diagnose tot en met die studie gedui. Ná die intervensie is ’n statisties beduidende toename (p = 0.00) in serum-ureum opgemerk, hoewel daar geen beduidende verskil in serumkreatinien en mikro-albuminurie waardes, voor en na behandeling, was nie. Biochemiese data voor en na die intervensie het geen statistiese verwantskap tussen die stadium van nefroblastoom en die reaksie op die dieetproteïenlading getoon nie. Boonop is geen statistiese verwantskap opgemerk tussen post-pubesensie en die reaksie op die proteïenlading, of tussen ’n langer tydsverloop tussen die diagnose en die studie en die voorkoms van hoë waardes in die biochemiese data nie. Gevolgtrekking Wat die studie-doelwitte betref, kon die navorsing nie statisties bewys dat deelnemers wat vir nefroblastoom behandel word, swak renale hantering van ’n eenmalige dieetproteïenlading toon nie. Die beperkinge van die studie sluit ‘n klein populasie met selfs kleiner subgroepe in; die resultate van die studie moet derhalwe in die konteks van die grootte van die populasie, geÏnterpreteer word.

The present study was conducted with the use of data from the Freshmen Health Study, a longitudinal study of college freshmen aged 18 that examined change in diet, physical activity, and weight during the first year of college at Utah State University (USU). Participants were assessed at different data collection periods including the beginning and end of their first semester attending USU. Participants' height and weight were measured and they were given a self-administered Food Frequency Questionnaire at each data collection. Simple linear and multivariate logistic regression was used to assess how dietary calcium intake related to weight change over a 16-week study period (one semester). There were 153 (82%) subjects who completed the second data collection during December 2005. The difference in weight between the beginning and end of fall semester was considered the main outcome. Changes in dietary calcium, dairy intake, and milk intake were also assessed as main outcomes. Means and standard deviations were used to describe population characteristics. Analysis of variance (ANOV A) was used to compare means across gender and quartiles of calcium intake. Simple linear regression and logistic regression were used to analyze the relationship between dietary calcium intake and weight change. The multivariate logistic model controlled for gender, physical activity, baseline BMI, and fruit and vegetable intake. Risk of weight gain was not associated with increasing quartile of dietary calcium intake in either unadjusted or multivariable logistic regression models. Subjects' mean calcium and dairy intake decreased significantly from baseline (p < 0.001). Although the average calcium intake for this population was less than current recommendations set by the FDA, dietary calcium intake did not appear to have any influence on weight change. Dairy and milk intake decreased significantly from high school to college; therefore, specific interventions to increase calcium intake from dairy foods would be appropriate in the adolescent population, especially in college freshmen.

Thesis (Mnutr)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Inappropriate feeding practices are a major cause of malnutrition in young children. Within this context, it has been well documented that the incidence of malnutrition rises sharply during the period from six to 18 months of age in most countries. Complementary feeding typically covers the period from six to 24 months of age. Renewed focus has been placed on the promotion of breastfeeding. Similar attention should be paid to complementary feeding. Six percent of deaths per year are preventable through good complementary feeding practises. To improve infant nutrition it is important to know the local infant and young child feeding practises present in communities but also to identify and understand the underlying factors that influence these practises. Aim The study aimed to describe the various factors that influence complementary feeding practices of infants aged 6 – 12 months in 2 communities (Avian Park and Zweletemba) in the Breede Valley district of the Western Cape. Methods The study was conducted from May – July 2012. A descriptive study design was used. A qualitative approach was followed with the use of focus group discussions with mothers / primary caregivers, fathers and grandmothers of infants aged 6 – 12 months. Results The findings of this study provide insight into different aspects regarding early cessation of breastfeeding that could lead to early introduction of complementary foods. In both Avian Park and Zweletemba the age of introduction of liquids and solids ranged from birth to 12 months. Various liquids such as water, over the counter medicine, high concentrated sugar beverages and low nutrient beverages were given to infants from as young as two days post-partum by means of a feeding bottle. Cow’s milk was also introduced before six months of age for reasons such as affordability, availability and because cow’s milk does not need boiling water for reconstitution like formula milk, especially when access to electricity is inadequate. Infants from both communities also received meelbol (flour and water beverage) fed either via feeding bottles (as a beverage) or as porridge fed to the infant with a spoon. Porridge (especially rice cereal and maize meal porridge) was introduced to infants from one week post-partum and infants from both areas also received family “food from the pot” before the age of 6 months. In this study it was found that it was most often a female (either the mother or the grandmother) in the household who was responsible for buying and preparing food and for feeding the infant. Health care workers, members of the mothers’ household as well as community members were identified as key role players in conveying information regarding breastfeeding and complementary feeding from birth to 1 year. Various factors were identified in this study that influenced suboptimal infant feeding practises in Avian Park and Zweletemba. The main factors identified were i) health, ii) physiological, iii) nutritional, iv) educational, v) behavioural, vi) financial and vii) social factors. Other aspects mentioned were viii) demographic and x) commercial factors. Conclusion Results indicated that the current practices and factors influencing the feeding practices in Avian Park and Zweletemba were similar there was very little to no cultural differences between the two communities in terms of current practices and influencing factors. The findings of this study have highlighted the importance of involving all household members in interventions, as well as the larger community in a public nutrition approach. Factors influencing current feeding practises should be considered carefully when planning future interventions to improve infant feeding practises.
AFRIKAANSE OPSOMMING: Onvanpaste voedingspraktyke is ‘n groot oorsaak van wanvoeding in jong kinders. Binne hierdie konteks is dit goed gedokumenteer dat die voorkoms van wanvoeding skerp styg gedurende die tydperk vanaf ses tot 18 maande ouderdom in die meeste lande. Komplimentêre voeding dek tipies die tydperk van ses tot 24 maande oud. Hernude fokus word geplaas op die bevordering van borsvoeding. Komplimentêre voeding behoort soortgelyke aandag te kry. Ses persent van sterftes per jaar is voorkombaar deur goeie komplimentêree voedingpraktyke. Om kindervoeding te verbeter is dit belangrik om bekend te wees met plaaslike baba- en jong kind praktyke in gemeenskappe, en ook om die onderliggende faktore wat hierdie praktyke beïnvloed te identifiseer en verstaan. Doelwit Hierdie studie het gepoog om die verskillende faktore ten opsigte van die komplimentêre voeding praktyke van babas tussen 6 – 12 maande te beskryf in 2 gemeenskappe (Avian Park en Zweletemba) in die Breede Vallei distrik van die Wes-Kaap. Metodes Die studie is uitgevoer vanaf Mei – Julie 2012. ‘n Beskrywende studie ontwerp is gebruik. ‘n Kwalitatiewe benadering is gevolg met die gebruik van fokusgroepbesprekings met moeders / primêre versorgers, vaders en oumas van babas tussen 6 – 12 maande. Resultate Die bevindinge van hierdie studie voorsien insae in die verskillende aspekte van die vroeë beëindiging van borsvoeding wat kan lei tot vroeë bekendstelling van komplimentêre voeding. In beide Avian Park en Zweletemba het die ouderdomme van insluiting van vloeistowwe en vaste stowwe gewissel van geboorte tot 12 maande.Verskeie vloeistowwe soos water, oor-die-toonbank-medisyne, hoë konsentrasie suiker drankies en lae voedingswaarde drankies was aan babas gegee so vroeg as twee dae post-partum deur middel van ‘n voedingsbottel. Koeimelk was ook gegee voor 6 maande, om redes soos bekostigbaarheid, beskikbaarheid en omdat koeimelk nie kookwater benodig vir hersamestelling soos formule melk nie, veral in situasies waar toegang tot elektrisiteit onvoldoende is. Babas van beide gemeenskappe was ook meelbol (meel en water drankie) gevoer óf via voedingsbottels (as ‘n vloeistof) of as ‘n pap wat gevoer word met ‘n lepel. Pap (veral ryspap en mieliemeelpap) was gegee vanaf een week post-partum en babas van beide gebiede het ook familie kookkos ontvang “vanuit die pot” voor 6 maande. In hierdie studie is bevind dat dit heel dikwels ‘n vrou (óf die moeder of ouma) in die huishouding is wat verantwoordelik is vir die koop en voorbereiding van voedsel asook die voer van die baba. Gesondheidswerkers, lede van die moeder se huishouding sowel as lede van die gemeenskap is geïdentifiseer as belangrike rolspelers in die oordrag van inligting oor borsvoeding en komplimentêre voeding vanaf geboorte tot een jaar. Die belangrikste faktore geïdentifiseer was verwant aan: i) gesondheid, ii) fisiologie, iii) voedingswaarde , iv) opvoedkunde, v) gedrag, vi) finansies en vii) sosiale faktore. Ander aspekte genoem is: vii) demografiese en x) kommersiële faktore. Gevolgtrekking Resultate het aangedui dat die huidige voedingpraktyke soortgelyk was in Avian Park en Zweletemba en dat daar baie min kulturele verskille tussen die twee gemeenskappe was in soverre huidige praktyke en faktore wat dit beïnvloed. Die bevindinge van hierdie studie het die belangrikheid daarvan uitgelig om al die lede van die huishouding, sowel as die breër gemeenskap in te sluit in intervensies met ‘n openbare voeding benadering. Faktore wat die huidige babavoeding praktyke beïnvloed moet versigtig oorweeg word tydens die beplanning van toekomstige intervensies om babavoeding praktyke te verbeter.

Thesis (Mnutr)--Stellenbosch University, 2004.
ENGLISH ABSTRACT: Objective: To assess the impact of a continuous auditing process on nutritional support in a tertiary paediatric intensive care unit. Design: Prospective, longitudinal audit initiated in 1994. Re-auditing took place almost every 2 years: 1994-1995, 1997-1998 and 2001, leading to completion of the audit cycle. Setting: An 8 bed Paediatric Intensive Care Unit (PICU) in StMary's Hospital London. Subjects: All ventilated patients admitted for more than a complete 24-hour period were included in the audit. The units' standard daily fluid charts were used for data collection. Data was collected until discharge from PICU or a maximum of 10 days. Incomplete and imprecise data was disregarded during the data analysis process. Outcome measures and interventions: The outcome measures include time taken to initiate nutritional support, the route of feeding and delivery of calories by day 3, judged by the Estimated Average Requirements (EAR) for energy. Feeding algorithms and protocols introduced after each audit: nasogastric feeding algorithm following the 1994-1995 audit, blind nasojejunal tube insertion technique and related feeding algorithms after the audit in 1997-1998. Results: Time taken to initiate enteral feeding was reduced from 15 hours (1994- 1995) to 5.5 hours (2001). The proportion of parenterally fed patients fell from 11% (1994-1995) to 1% (200 1 ). The proportion of enterally fed patients via the nasojejunal route rose from 1% (1994-1995) to 20% (2001). An increase was noticed in patients reaching 50% and 70% of energy requirement by day 3 following admission was documented: 7% in1994-1995 to 35% in 2001 for 70% of EAR (p = 0.0008) and 18% in 1994-1995 to 58% in 2001 for 50% of EAR. (p< 0.0001) Conclusion: This audit process demonstrates the effectiveness of continuous auditing in an intensive care unit in improving the quality of nutritional support. This is possible only with a multi-disciplinary team approach.
AFRIKAANSE OPSOMMING: Doel: Om die impak van 'n deurlopende ouditerings proses op die voedingsondersteuning in 'n tersi~re pediatriese intensiewesorg-eenheid te evalueer. · Studie Ontwerp: 'n Prospektiewe, longetudinale oudit is in 1994 geYnisieer. Herouditee·ring het ongeveer elke 2 jaar plaasgevind: 1994-1995, 1997-1998 en 2001. Dit het tot die voltooiing van 'n ouditering siklus gelei. Plek: 'n Agt-bed Pediatriese lntensiewesorgeenheid (PISE) in StMary's Hospitaal London, Engeland. Pasiente: Alle geventilleerde pasiente wat opgeneem was vir !anger as 'n volledige 24 uur-periode is by die oudit ingesluit. Die eenheid se standard daaglikse vogkaarte dokumentasie is gebruik vir data-insameling. Data-insameling het plaasgevind tot en met ontslag vanuit die PISE vir 'n maksimum van 10 dae. Onvolledige en onakkurate data is uitgesluit tydens die data analise proses. Uitkomste en Intervensie: Die uitkomste is gemeet deur die impak van die ouditerings proses te evalueer ten opsigte van tydsduur voordat daar voedings geYnisieer is, die voedingsroete en die hoeveelheid energie gelewer teen dag 3, vergelyk met die geskatte gemiddelde energie behoefte. Voedings-algoritmes en protokolle is geYmplementeer na elke oudit: nasogastriese voedings-algoritmes is na die 1994-1995 oudit geYmplimenteer, 'n blinde nasojejunale buisinplasingstegniek en I relevante voedings algoritmes het na die 1997-1998 oudit gevolg. Resultate: Die tydsduur om voedingondersteuning te inisieer het van 15 ure (1994- 1995) tot 5.5 ure (2001) verminder. Die persentasie pasiente wat parenterale voeding ontvang het, het gedaal van 11% (1994-1995) tot 1% (2001), met 'n toename in enterale voeding via die nasojejunale roete van 1 %(1994) tot 20% (2001). 'n Toename in pasiente wat meer as 50% en 70% van hul energie behoefte bereik het teen dag 3 is opgemerk: 7% in 1994-1995 en 35% in 2001 het meer as 70% van die geskatte gemiddelde behoefte vir energie ontvang. (p=0.0008) Agtien persent het in 1994-1995 en 58% in 2001 meer as 50% van hul gemiddelde energie behoeftes bereik (p < 0.0001). Gevolgtrekking: Hierdie ouditerings proses demonstreer die effektiewiteit van deurlopende ouditering in 'n intensiewesorg-eenheid deur die verbetering van die kwalitiet van voedingondersteuning. Dit is slegs moontlik met 'n multidissiplinere span benadering.

The objective of this study was to determine Thai women's nutrition awareness of folic acid and its role in the prevention of neural tube defects. Three hundred and two Thai women between 18-45 years completed a 30 itemized survey. There was a significant lack of nutrition awareness of folic acid. Many women (n= 274; 91.9%) had not heard of neural tube defects (NTD) and only 8.1 % (n=24) had heard of spina bifida/NTD. More than 50% (n=176) were unaware of NTD. Only 11.6% of the women (n=35) thought consuming vitamins during pregnancy would reduce the risk of birth defects. More than 80% of the women reported the best time to take folic acid supplement was during pregnancy. Less than 20% of the women indicated taking folic acid supplement before or after pregnancy. In this population, nutrition awareness of folic acid was minimal.
Department of Family and Consumer Sciences

Adult Type II diabetes is an increasing public health problem, particularly among very low-income minority populations. The purpose of this study was to create a nutritional guide for a diabetic specific meal plan with an accompanying food pantry nutrition packet for very low-income Type II diabetic patients at a rural Mississippi Free Clinic. The practice-focused question is: Will a nurse-prepared nutritional guide with supplemental food packets improve the glucose control in low income diabetic patients? The gap in practice is that there has been no structured nutrition education guide and no food pantry support plan for Type II adult diabetics. The theoretical framework is Cockerham's health lifestyle theory. A project goal was to prepare food packets specific to the Type II diabetic patients proved not viable due to limited donations of food resources, no regular source of fresh foods, and limited refrigeration space at the food pantry. However, education resources were developed for meal planning using the glycemic index, integration of cultural food preferences, and simple food log for the patient to chart daily meals. Recommendations include program evaluation of the use of these educational materials on patient A1c levels and weight in this population. The food pantry can offer diabetic specific meal packets with community social investment. Social change is addressing self-management of nutritional needs of very low income diabetic patients. Implication for nursing practice includes promotion of dialogue amongst different disciplines interested in the nutritional aspect of improving A1c and glucose levels.

Thesis (MNutr)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Objectives: To measure the impact on nutrition knowledge; to ascertain the opinions and practices related to nutrition and physical activity, tuck shop visits, and dietary quality of Grade 4 learners; as well as the perceptions on and acceptability of the ‗Fun Food Game‘ (FFG) as nutrition education tool as evaluated in selected Grade 4 learners and educators. Design: A before-after, experimental study with analytical components. Setting: A purposive sample of four schools in the City of Cape Town district of the Western Cape province. Schools A and B in a higher socio-economic area served as intervention school (HIS) and control school (HCS), whereas schools C and D were in a lower socio-economic area and served as intervention school (LIS) and control school (LCS). Subjects: Grade 4 English-speaking boys (n=85), girls (n=90) and Life Orientation educators (n=10). Methods: Pre-tested questionnaires were used to determine change in nutrition knowledge, opinions and practices, both related to nutrition and physical activities in a pre-and post-setting, as well as the perceptions on and acceptability of FFG as a nutrition education (NE) tool for Grade 4 learners and educators. A ‗Dietary Diversity Questionnaire‘ was used to establish the ‗Dietary Diversity Score‘ (DDS), and to note tuck shop visits. Questionnaires were pre-tested in a pilot study. Results: Increased nutrition knowledge and improved opinion on nutrition and physical activities were measured in all schools, but practices related to nutrition and physical activities as well as visits to the tuck shop showed mixed results. In the pre- and post-setting, a DDS of 5 was measured in the HIS and HCS, with a DDS of 5 in the pre- and 6 in the post-setting in the LIS and LCS. Fewer learners had a DDS<4 in the post-setting. Consumption of most food groups and eating breakfast were higher in the post-setting. Bringing lunch boxes to school scored lower in the intervention schools. More tuck shop visits were reported in the LIS and LCS. Most (80% n=8) educators indicated a strong need for NE for themselves. All educators indicated self-learning as a means of familiarising themselves with the content of NE. Sources of nutrition advice included magazines (90% n=9), the Internet (80% n=8) and textbooks (70% n=7). A strong need for NE was expressed by all educators; however, they stated that it should not increase their work load. Educators ‗strongly agreed‘ that the educational nutrition board game FFG can be classified as ‗Health Promotion‘. Overall, learners indicated that playing FFG was a positive experience. Conclusion: Playing FFG and/or having an increased awareness regarding nutrition and physical activities at schools could have had a positive impact on nutrition knowledge and behaviour that could have resulted in positive behaviour, but no definite conclusion can be made in this regard. Nutrition behaviour was more positively influenced in the lower socio-economic schools. Implementing the Health Promoting Schools concept, where Nutrition Education Programmes form part of a multi-component strategy, is recommended.
AFRIKAANSE OPSOMMING: Doel: Om die impak van voedingskennis, opinies en praktyke verwant aan voeding en fisiese aktiwiteite, snoepiebesoeke asook dieetkwaliteit van Graad 4 leerders te bepaal, sowel as die persepsie en aanvaarbaarheid van ‗Fun Food Game‘ (FFG) as hulpmiddel in voedingsopleiding soos geëvalueer deur geselekteerde Graad 4 leerders en -onderwysers. Ontwerp: ‗n Voor-na, eksperimentele studie met analitiese komponente Omgewing: ‗n Doelbewuste groepskeuse van vier skole. Skole A en B in ‗n meer gegoede area het as intervensie skool (HIS) en kontrole skool (HCS) gedien, terwyl skole C en D in ‗n minder gegoede area as intervensie skool (LIS) en kontrole skool (LCS) gedien het in die Stad Kaapstad distrik van die Westelike Provinsie. Deelnemers: Graad 4 Engelssprekende seuns (n=85), dogters (n=95) en Lewensoriënteringsonderwysers (n=10) Metodes: Voorafgetoetsde vraelyste is gebruik om te bepaal of voedingskennis, opinies en praktyke beide verwant aan voeding en fisiese aktiwiteite, voor en na die studie verander het, asook die persepsie en aanvaarbaarheid van FFG as ‗n hulpmiddel in voedingsopleiding vir geselekteerde Graad 4 leerders en onderwysers. ‗n Dieetdiversiteit Vraelys (‗Dietary Diversity Questionnaire‘ – DDQ) is gebruik om ‗n Dieetdiversiteit Telling (‗Dietary Diversity Score‘ – DDS), sowel as snoepiebesoeke te bepaal. ‗n Loodsstudie is uitgevoer om die vraelyste te toets. Resultate: ‗n Toename in voedingkennis en verbeterde opinies oor voeding en fisiese aktiwiteite is in alle skole gevind, maar praktyke oor voeding en fisiese aktiwiteite, asook snoepiebesoeke het gemengde resultate getoon. In die voor- en na-toetsing is ‗n DDS van 5 in HIS en HCS bepaal, met ‗n DDS van 5 in die voor- en 6 in die na-toetsing in LIS en LCS. Minder leerders het ‗n DDS<4 in die na-toetsing gehad. Inname van die meeste voedselgroepe sowel as ontbyt het in die skole toegeneem. Die bring van kosblikke het in die intervensie skole verminder. Die hoogste frekwensie snoepiebesoeke kom voor by die LIS en LCS. Meeste (80% n=8) onderwysers het ‗n sterk behoefte aan voedingsopleiding vir hulself aangedui. Alle onderwysers dui aan dat die inhoud van voedingskennis deur selfleer verhoog word. Tydskrifte (90%, n=9), Internet (80%, n=8) en handboeke (70%, n=7) word as bronne van voedingsadvies beskryf. ‗n Sterk behoefte vir opvoedkundige voedingsopleiding is deur al die onderwysers aangedui, maar sonder dat dit hul werkslading moet verhoog. Die onderwysers is ―sterk oortuig‖ daarvan dat die opvoedkundige voedingsbordspeletjie FFG, as ―Gesondheidsbevordering‖ geklassifiseer kan word. In die algemeen het leerders dit baie positief ervaar om FFG te speel. Samevatting: Die speel van FFG en/of ‗n groter bewusmaking van voeding en fisiese aktiwiteit wat by die skole plaasgevind het, kon ‗n positiewe impak op voedingskennis en -gedrag gehad het, wat kon lei tot positiewe gedrag, maar geen definitiewe gevolgtrekking kan gemaak word in die verband nie. Voedingsgedrag in die mindergegoede skole is meer positief beïnvloed. Implimentering van die Gesondheidsbevorderende Skole konsep, waar Voedingsopleidingsprogramme deel vorm van ‗n multi-komponent strategie, word aanbeveel.

This thesis summarises a series of academic publications that make a contribution to the field of sports nutrition over a period of 30 years. It begins with research in the field of carbohydrate and endurance sport reflecting the early era of research into carbohydrate and endurance performance, and evolves into studies investigating the impact of sports nutrition and hydration on team sports. It presents papers and other peer reviewed outputs that focus on the application of scientific knowledge to enhance human performance, whilst demonstrating the increasing awareness of the relative importance of carbohydrate and hydration in a range of both female and male team and individual sports. The thesis also highlights the challenge faced by the manufacturers of sports nutrition products in making use of advances in science to develop new and innovative products. The thematic nature of this thesis shows how sports nutrition continues to evolve. As science identifies new and legal means of enhancing human performance, so sport, athletes and coaches will demand more advanced and specialised approaches to refuelling and hydration. This thesis draws together findings from a series of publications which demonstrate how scientists, coaches, athletes and sports nutrition manufacturers need to work closely together to research, identify and interpret the next stages in an exciting and demanding area of research. It also reflects the scientific advancement in the field of sports nutrition over a thirty year period, identifies possible areas for future research, and the continued application of hydration and nutrition strategies to enhance male and female endurance and team sports.

The aim of this study was to characterize the fat composition of camel milk fat and camel hump fat and thereby assist in the technological development of camel milk and meat based products. The latter is of major interest in parts of Africa where the camel resides in large numbers. A combination of silver-ion and reversed phase HPLC enables the isolation of triglycerides according to their saturation class and carbon number. Subjection of the isolated triglycerides to enzymatic splitting with lipase and subsequent analysis of the free fatty acids generated enables a positional analysis of the main triglyceride components and thus a characterization of the fat. The analytical techniques employed may equally well be applied to other fats or oils to allow their characterization.

Thesis (Mnutr)--Stellenbosch University, 2003.
ENGLISH ABSTRACT: INTRODUCTION: Malnutrition is a silent emergency. WHO estimates that 55% of all child deaths in developing countries are associated with malnutrition. Inadequate dietary intake and disease are the two immediate causes of malnutrition. The underlying causes are household food insecurity, inadequate maternal and child-care and poor water/ sanitation and inadequate health services. Stunting is a major problem in pre-school children in South Africa. This indicates a long term inadequate dietary intake. Furthermore, the initiation of breastfeeding in South Africa is about 90%, and the duration thereof tends to be less than 3 months after birth. A great majority of children in this country consume a diet deficient in energy and of poor nutrient density to meet their micronutrient requirements. The aim of this study was to identify feeding practices of infants that could contribute to the development of malnutrition. METHOD: This was a cohort study with a prospective experimental design. Forty-four of the original 73 mother-infant pairs that were recruited, were interviewed monthly on feeding practices of the infants. Anthropometric measurements (weight and height of the infants) were measured monthly. RESULTS: Weight-for-age Z-scores dropped significantly with age from around 4 months, when weaning had started. Inadequate dietary intake, more specifically weaning practices and breastfeeding practices, were identified as the immediate cause that could contribute to the development of malnutrition in this community. Except for the positive relationship between the level of education of the father and an increase in HAZ over time, growth was not affected by socio-economic and demographic factors in this community. This is probably because of the fact that there were very small differences in socio-economic and demographic factors. CONCLUSION: Weaning and breastfeeding practices should be addressed in all nutrition education programmes.
AFRIKAANSE OPSOMMING: INLEIDING: Wanvoeding is 'n stil gevaar. Die WGO skat dat daar 'n verband is tussen wanvoeding en ongeveer 55% van alle kindersterftes in ontwikkelende lande. 'n Onvoldoende dieetinname en siekte is die twee onmiddellike oorsake van wanvoeding. Onvoldoende huishoudelike voedselsekuriteit, onvoldoende moeder- en kindsorg en swak sanitasie en watervoorsiening asook onvoldoende gesondheidsorg is die onderliggende oorsake. Dwerggroei is 'n groot probleem in Suid-Afrika onder voorskoolse kinders. Dit dui op 'n langdurige onvoldoende dieetinname. Bydraend hiertoe, is die aanvang van borsvoeding in Suid-Afrika ongeveer 90%, maar die duurte van borsvoeding is minder as 3 maande na geboorte. Die meerderheid van alle kinders in Suid-Afrika se dieet het 'n tekort aan energie en die nutriëntdigtheid van hulle diëte voldoen nie aan hulle daaglikse behoeftes ten opsigte van mikronutriënte nie. Die doel van hierdie studie was om voedingspraktyke te identifiseer wat kan bydra tot die ontwikkeling van wanvoeding. METODE: Dit was 'n kohortstudie met 'n prospektiewe eksperimentele ontwerp. Vier-en-veertig van die oorspronklike aanvanklike moeder-babapare wat gewerf is, is maandeliks ondervra met betrekking tot die voedingspraktyke van die baba en antropometriese metimgs (gewig en lengte van die baba) is maandeliks geneem. RESULTATE: Z waardes van gewig vir ouderdom het beduidend gedaal namate die kinders ouer geword het, veral vanaf 4 maande, toe spening begin het. 'n Onvoldoende dieetinname, meer spesifiek spenings- en borsvoedingspraktyke, is geïdentifiseer as die onmiddellike oorsake wat tot die ontwikkeleing van wanvoeding kan bydra in hierdie gemeenskap. Daar was 'n positiewe verband tussen lengtegroei (Z waardes van lengte vir ouderdom) en die vlak van opvoeding van die vader. Groei is nie deur die ander sosio-ekonomiese en demografiese faktore beïnvloed nie, moontlik as gevolg van die klein verskille in sosio-ekonomiese en demografiese eienskappe van die studie populasie. GEVOLGTREKKING: Spenings- en borsvoedingpraktyke behoort aandag te geniet in alle voedingsvoorligtings-programme.

Purpose: To review the roles of the different vascular beds nourishing the inner retina [retinal ganglion cells (RGCs)] during normal development of the human eye, using our own tissue specimens to support our conclusions. Methods: An extensive search of the appropriate literature included PubMed, Google scholar, and numerous available textbooks. In addition, choroidal and retinal NADPH-diaphorase stained whole mount preparations were investigated. Results: The first critical interaction between vascular bed and RGC formation occurs in the sixth to eighth month of gestation leading to a massive reduction of RGCs mainly in the peripheral retina. The first 3 years of age are characterized by an intense growth of the eyeball to near adult size. In the adult eye, the influence of the choroid on inner retinal nutrition was determined by examining the peripheral retinal watershed zones in more detail. Conclusion: This delicately balanced situation of RGC nutrition is described in the different regions of the eye, and a new graphic presentation is introduced to combine morphological measurements and clinical visual field data.

Human promyelocytic leukemic cells (HL-60) possess well regulated expression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, acylCoA:cholesterol acyltransferase (ACAT), and receptor-mediated low density lipoprotein (LDL) catabolism, but lack receptor-mediated acetyl-LDL processing. Differentiation of HL-60 cells with tetramyristic phorbol acetate (TPA) is accompanied by the loss of receptor-mediated LDL degradation and no expression of a functionally active scavenger receptor. 1,25-Dihydroxyvitamin D₃ (D₃)-induced HL-60 macrophages possess specific and saturable receptor-mediated binding for LDL, with an apparent K(d) of 29 μg/ml and a B(max) of 219 ng/mg. Receptor-mediated LDL degradation is specific for apoB and apoE containing lipoproteins; it is calcium dependent, and is inhibited by pronase and chloroquine. Differentiation of HL-60 cells with D₃ for 2 days induces a 45-fold increase in acetyl-LDL degradation rate compared to undifferentiated cells. Receptor-mediated degradation of acetyl-LDL is specific for acetyl-LDL, calcium independent, inhibited by chloroquine, pronase and fucoidin treatment, and is not regulated by cellular cholesterol. Acetyl-LDL binding studies demonstrated a K(d) of 36 μg/ml and a B(max) 313 ng/mg. Delivery of cholesterol via receptor-mediated catabolism of LDL or acetyl-LDL results in significant suppression of sterol synthesis and HMG-CoA reductase activity, and significant induction of ACAT activity relative to macrophages incubated with LPDS (P < 0.001). However, receptor-mediated degradation of acetyl-LDL, but not LDL, significantly increases cholesteryl ester content (P < 0.001). D₃-induced HL-60 macrophages incubated with or without LDL for 48 hr exhibited large empty vacuoles with little or no lipid stainable material. In contrast, macrophages incubated with acetyl-LDL exhibited a dramatic increase in lipid stainable material which imparted the macrophages with a foamy appearance. In conclusion, HL-60 cells treated with D₃ for 48 hr undergo activation differentiation assuming the structural and functional characteristics of human monocyte-derived macrophages. Thus, D₃-induced HL-60 macrophages are a suitable in vitro system to study lipoproteins and cholesterol regulation as related to macrophage involvement in atherosclerosis.

My thesis research has examined the fatty acid composition of serum triacylglycerol, phospholipid and cholesterol ester in 2793 participants who took part in the 1997 National Nutrition Survey - a national population-based survey of New Zealand adolescents and adults aged or [greater than or equal to]̲15 y. Differences in serum fatty acids by sex, age, ethnicity, body mass index and smoking - independent of dietary fat intake - were determined. Serum fatty acids were used as biomarkers of saturated and polyunsaturated fat intake to predict population serum total cholesterol concentrations. The association between n-3 long-chain polyunsaturated fatty acids in serum phospholipid and mental and physical wellbeing, as assessed by the short form-36, was determined. Serum fatty acids have been used as biological markers of fat intake and to predict the risk of disease. The fatty acid composition of serum triacylglycerol, phospholipid and cholesterol ester is subject to alteration by dietary fat but overall, is largely controlled by metabolic enzymes. Non-dietary variables - sex, age, body mass index or cigarette smoking - may influence the activity of these enzymes, which will subsequently alter the fatty acid composition but the extent to which these affect serum fatty acid composition in the general population is poorly understood. Our results showed that the proportion of docosahexaenoic acid in serum phospholipid and cholesterol ester was significantly greater in women by 0.15 and 0.02 mol%, respectively in comparison to men whereas, the proportion of eicosapentaenoic acid was significantly greater in men by 0.08 and 0.1 mol%, respectively, after adjusting for age, ethnicity, body mass index and smoking. A number of differences in the proportion of palmitoleic acid in serum triacylglycerol, phospholipid and cholesterol ester were detected; palmitoleic acid increased across the age categories in women (15-24, 25-44, 45-64 65+ y), was higher in women compared to men, New Zealand Europeans compared to New Zealand Maori and Pacific People, those with a body mass index or [greater than or equal to] 30 kg/m� compared to those with a body mass index < 25 kg/m� and in current smokers in comparison to non-smokers. In women, there was an inverse trend in the proportion of linoleic acid in serum phospholipid and cholesterol ester across the age categories. The proportion of linoleic acid in serum triacylglycerol, phospholipid and cholesterol ester was lower in smokers by 2.19, 1.04 and 0.75 mol%, respectively in comparison to non-smokers. None of these differences could be explained by a difference in dietary fat intake. Consequently, sex appears to affect the metabolism of n-3 long-chain polyunsaturated fatty acids independent of dietary fat intake and metabolic differences associated with age, body mass index and smoking may be at play for a number of other serum fatty acids notably, palmitoleic and linoleic acids. Evidence for a role of dietary fat as a predictor of serum cholesterol concentrations in the general population is conflicting. On one hand, results from cholesterol-lowering dietary intervention trials show unequivocally that decreasing saturated fat intake produces a meaningful reduction in serum cholesterol concentrations. On the other hand, the results of large observational studies show little association between saturated fat intake and cholesterol concentrations. The lack of association in the latter studies may result from errors in dietary assessment and therefore, using serum fatty acids as biomarkers of fat intake may overcome the limitations associated with typical dietary assessment techniques. Participants were divided into quintiles of increasing proportion of serum fatty acids. Each one SD increase in the myristic acid composition of serum cholesterol ester, triacylglycerol and phospholipid was associated with an increase in cholesterol of 0.19, 0.10 and 0.13 mmol/L, respectively after adjusting for confounding variables. The difference in cholesterol concentrations between those categorised into the highest and lowest quintiles of serum cholesterol ester myristate was 0.48 mmol/L. A one SD increase in the linoleic acid composition of serum cholesterol ester, triacylglycerol and phospholipid corresponded to a decrease in cholesterol of 0.07, 0.05 and 0.07 mmol/L, respectively. The difference in cholesterol concentrations between the 1st and 5th quintiles of serum cholesterol linoleate was 0.18 mmol/L. Intake of saturated and polyunsaturated fats, as measured using serum fatty acids, are important determinants of cholesterol concentrations in New Zealanders. It has been hypothesised that a lower intake of n-3 long-chain polyunsaturated fatty acids, largely of marine origin, is implicated in the aetiology of depressive disorder. Results from the majority of observational studies have shown that depressed participants have a lower proportion of eicosapentaenoic or docosahexaenoic acid in phospholipids compared to controls but evidence for an improvement in depressive symptoms after supplementation with n-3 long-chain polyunsaturated fatty acids is conflicting. There is little known about the role that n-3 long-chain polyunsaturated fatty acids may have as predictors of mental wellbeing in the general population. Participants were categorised into quintiles of increasing n-3 long-chain polyunsaturated fatty acids in serum phospholipid. There was no significant trend in self-reported mental wellbeing - the mental component score - across the quintiles of eicosapentaenoic, docosapentaenoic and docosahexaenoic acids or the sum of these three fatty acids after adjusting for confounding variables. There was a significant trend in the mental component score across the quintiles of the ratio of eicosapentaenoic/arachidonic acid; the difference between the highest and the lowest quintile was 6.6 points. There were significant positive trends in self-reported physical health - the physical component score - across the quintiles of eicosapentaenoic and docosapentaenoic acids as well as the ratio of eicosapentaenoic/arachidonic acid ratio; the difference between the 1st and 5th quintiles were 8.6, 6.0 and 8.9 points, respectively. Overall, there appears to be little association between the n-3 long-chain polyunsaturated fatty acid composition of serum phospholipid and self-reported mental health in a population of low fish consumers; however, the proportion of n-3 long-chain polyunsaturated fatty acids may be an important predictor of physical wellbeing in New Zealanders.

Thesis (M.S.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on October 25, 2007) Vita. Includes bibliographical references.