<p dir="ltr">Accumulating evidence suggests a potential role for almond consumption in ameliorating post-prandial glycemia. Yet their effect on HbA1c, an indicator of long-term glycemic control, is mixed. The purpose of this study was to examine the potential of sustained almond consumption to reduce HbA1c concentrations among individuals with elevated HbA1c concentrations. A 16-week randomized, parallel-arm, controlled trial was conducted. Eighty-one adults with elevated HbA1c concentrations (>5.7%) were randomly assigned to incorporate two servings (2 oz) of raw almonds (A group; N=39) or energy-matched snacks (pretzels C group; N=42) into their daily diets. Half of these intervention foods were to be ingested at breakfast and the other half as a replacement for either a mid-morning or mid-afternoon snack. Throughout the intervention period, measurements were made of body weight, body composition, plasma lipids, HbA1c, alpha and gamma-tocopherol, glycemia (by meal tolerance test) and continuous glucose monitoring, dietary intake, and hedonic responses to test foods at stipulated time points. Participants consuming almonds ingested 253 kcal/d more than participants in the control group (p=0.02), but this did not result in a significant difference in body weight (A: 0.2kg SEM ±0.5, C: 0.4kg SEM ±0.5); p>0.05). No statistically significant differences were observed in HbA1c concentrations (A: 0.1% SEM ±0.1, C: 0% SEM ±0.1; p>0·05), blood chemistries, body composition, or glycemia over time or between groups. However, Healthy Eating Index scores improved within the almond group as compared to the control group (A: 8.3 points SEM ±1.9, C: -2.3 points SEM ±2.1; p<0.001). Additionally, the hedonic rating of almonds did not decline within the almond group in comparison to the control group's reduced liking of the pretzel snack. Alpha-tocopherol increased significantly, and gamma-tocopherol tended to decrease in the almond group, indicating compliance with the dietary intervention. Overall, daily ingestion of 2 oz of raw almonds in a regular diet for 16 weeks did not alter short-term or longer-term glycemia or HbA1c concentrations in adults with elevated HbA1c concentrations, but they were well-tolerated and improved diet quality without promoting weight gain.</p>

Thesis (MNutr)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Objectives: Children with autism spectrum disorder (ASD) are known to have feeding difficulties. This study gathered information from parents/caregivers with children diagnosed with ASD. The following aspects were investigated: early feeding history, food preferences, sensory issues, current dietary practices and the use of nutritional supplements and special diets. The study also gathered information regarding these families’ experience with dietitians in supporting them with advice related to dietary problems. Methodology: An online questionnaire was used and the link to the study was placed on the National Autistic Society (NAS) of the United Kingdom’s website to recruit participants. Parents/ caregivers of children aged between 3-16 years and diagnosed with ASD, who resided in England, could take part in the study. Results: Three hundred and twenty five parents/ caregivers participated in the study. The mean age of children was 9.5 years. The majority of children were male (85%). The most common feeding problem was the transition from stage 1 weaning foods to more textured food (55.6%). Sensory problems played a large role in food acceptance. Clear preferences were made for crunchy (81.5%) or dry foods (79%), followed by food with a smooth consistency (69.8%) such as yogurt. Food appearance and presentation (64%) was the main determinant of food acceptance and specific brands and packaging played a major role. Habitual food intake and continually choosing the same foods for meals were present in the majority of children (75.6%). Specific preference was given to the following foods: starchy vegetables (62.6%), refined carbohydrates (81%), processed meat products (69.2%) and dairy products (68.6%). The use of ‘special’ and exclusion diets were not popular. However, where specifically gluten and/ or casein were excluded (19%, n=55), it was generally excluded for more than one year. Reported observations with these exclusions were: improvement in bowel habits, sleep, concentration, behaviour and social communication. The use of nutritional supplements were significantly higher (p<0.5) where exclusion diets were used. A large number of children (43.4%, n=23) on exclusion diets, have not been consulted by a dietitian. Most parents /caregivers (58.1%) had the perception that dietitians were lacking knowledge of ASD and had inadequate knowledge of current dietary interventions for children with ASD (61.7%). However, parents felt that it was reassuring to consult a dietitian, that practical advice was given to improve dietary intake and that generally it reduced their concern regarding their child’s dietary intake. Conclusion: The study highlights the complexity of ASD and the variable effect it has on eating, behaviour and dietary intake. The use of the gluten and casein free (GFCF) diet may improve general wellbeing in some children with ASD when used appropriately and warrants further investigation. It is concerning that only a minority of children on exclusion diets are consulted by dietitians to ensure nutritional adequacy. Due to the complexity of ASD and in the absence of clear guidance for dietary interventions, dietitians who work with children with ASD need to be supported by continued training opportunities in order to enhance their competencies and optimise their service delivery. / AFRIKAANSE OPSOMMING: Doelwitte: Kinders wat aan Outismespektrum-steuring (OSS) lei is geneig om voedingsprobleme te hê. Die studie het inligting ingesamel van ouers en versorgers met kinders wat met OSS gediagnoseer is. Die volgende aspekte is ondersoek: vroeë voedingsgeskiedenis, voedsel voorkeure, sensoriese probleme, huidige eetgewoontes en die gebruik van nutriëntaanvullings en spesiale diëte. Die studie het ook inligting ingesamel aangaande gesinne se ondervinding met dieetkundiges en ondersteuning met dieetprobleme. Metodologie: ‘n Elektroniese vraellys is gebruik en die skakel na die studie was op die webwerf van die National Autistic Society (NAS) van die Verenigde Koninkryk geplaas om deelnemers te werf. Ouers/ versorgers van kinders tussen die ouderdomme van 3-16 jaar, met ‘n diagnose van OSS en woonagtig in Engeland, kon deelneem aan die studie. Resultate: Drie honderd vyf en twintig ouers/ versorgers het deelgeneem aan die studie. Die gemiddelde ouderdom van die kinders was 9.5 jaar en 85% was manlik. Die mees algemene voedingsprobleem vir kinders met OSS was die oorgangsfase van gladde speningsvoedsel na growwer voedsel (55.6%). Sensoriese probleme het ‘n groot rol gespeel in voedselaanvaarding. Daar was duidelike voorkeure vir bros (81.5%) en droë voedsel (79%), gevolg deur voedsel met ‘n gladde tekstuur soos jogurt (69.8%). Die voorkoms en aanbieding van voedsel het grootliks bepaal of voedsel aanvaarbaar (64%) is. Spesifieke handelsmerke of verpakkings het ‘n groot rol gespeel (64.7%). Die meeste van die kinders (75.6%) het vaste eetgewoontes gehad en dieselfde kos tydens maaltye gekies. Die volgende voedselsoorte was verkies: styselryke groente (62.6%), verfynde koolhidrate (81%), geprosesseerde vleis produkte (69.2%) en suiwel produkte (68.6%). Die gebruik van spesiale en uitsluitingsdiëte was ongewild. Waar gluten- en kaseïen-uitsluitingsdiëte (19%, n=55) gebruik is, is dit meestal vir langer as een jaar gebruik. Met die gebruik van uitsluitingsdiëte is verbeteringe waargeneem in stoelgang gewoontes, slaap, konsentrasie, gedrag en sosiale kommunikasie. Die gebruik van nutriëntsupplemente was beduidend hoër (p<0.5) in die groep waar uitsluitingsdiëte gebruik is. ‘n Hoë persentasie kinders (43.4%, n=23) wat op uitsluitingsdiëte was, is nie deur dieetkundiges gekonsulteer nie. Die meeste ouers /versorgers (58.1%) het gevoel dat dieetkundiges gebrekkige kennis oor OSS en dieetverwante probleme het, asook onvoldoende kennis van huidige dieet intervensies vir kinders met OSS (61.7%). Ouers het wel gevoel dat dit gerusstellend was om dieetkundiges te gaan spreek vir praktiese raad om dieet inname te verbeter. Dit het ook hul kommer veminder aangaande kinders se diëte. Gevolgtrekking: Die studie benadruk die kompleksiteit van OSS en die wisselende effek wat dit op eetgewoontes, gedrag en voedsel inname het. Die gebruik van die gluten- en kaseïenvrye diëte kan moontlik die gesondheid en welsyn van sommige kinders met outisme verbeter mits dit reg gebruik word, maar vereis verdere navorsing. Dit was kommerwekkend dat ‘n minderheid van die kinders op uitsluitingsdiëte deur dieetkundiges gekonsulteer word om voldoende nutriëntinname te verseker. Aangesien OSS ‘n komplekse toestand is en daar ‘n gebrek is aan duidelike riglyne vir dieet intervensies, word dit aanbeveel dat dieetkundiges wat met kinders met OSS werk ondersteun word deur opleidingsgeleenthede om hul vaardighede te verbeter en dienslewering te optimaliseer.

Capillary electrophoresis mass spectrometry (CE-MS) is a versatile instrumental method for metabolomics, which allows for comprehensive metabolite profiling of volume-limited biological specimens in order to better understand the molecular mechanisms associated with chronic diseases, including an alarming epidemic of obesity worldwide. Multiplexed CE separations enable high-throughput metabolite screening with quality assurance to prevent false discoveries when combined with rigorous method validation, robust experimental designs, complementary statistical methods, and high-resolution tandem mass spectrometry (MS/MS) for unknown metabolite identification. In this thesis, multiplexed CE-MS technology is applied for both targeted and untargeted metabolite profiling of various biological fluids, including covalently bound thiol-protein conjugates, as well as free circulating metabolites in serum and plasma, and excreted/bio-transformed compounds in urine due to complex host-gut microflora co-metabolism. This work was applied to characterize aberrant metabolic responses of obese subjects in response to dietary challenges, and measure the benefits of dietary interventions that reduce adiposity without deleterious muscle loss. Chapter 2 presents, a simple, sensitive yet robust analytical protocol to expand metabolome coverage in CE-MS for the discovery of labile protein thiols in human plasma using a rapid chemical derivatization method based on N-tert-butylmaleimide (NTBM). Chapter 3 describes targeted metabolite profiling of serum and plasma to investigate the differential metabolic responses between healthy and unhealthy obese individuals before and after consumption of a standardized high-caloric meal, respectively. Chapter 4 of this thesis describes an untargeted metabolite profiling strategy for urine using multisegment-injection (MSI)-CE-MS for elucidating the effects of protein supplementation following a short-term dietary weight-loss intervention study. This work revealed six urinary metabolites that were classified as top-ranking treatment response biomarkers useful for discriminating between subjects consuming carbohydrate (control), soy, and whey supplemented diets. In summary, this thesis demonstrated the successful implementation of multiplexed CE-MS technology for biomarker discovery in nutritional-based metabolomic studies as required for more effective treatment and prevention of obesity for innovations in public health. / Thesis / Doctor of Philosophy (PhD)