M. Tech. (Department of Biotechnology, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Obesity has steadily increased and represents a major public health problem worldwide, reducing quality of life and causing a range of health problems. Obesity has emerged as the fifth leading risk of global deaths. Annually, 2.8 million adults die as a result of being overweight or obese. The increase of obesity remains inexplicable in terms of genetic susceptibility to obesity. The genetic loci identified by genome-wide association studies (GWASs) explains about 2% of the heritability for obesity. Perhaps other factors such as epigenetics may be involved in the increase of obesity and may offer solutions for the management of obesity. Epigenetics is defined as a heritable change in gene expression without altering the genome sequences. It may help in providing a logical explanation between the genome and environment which shapes obesity risk and may help to explain the "missing heritability". Epigenetics may affect two mechanisms, namely: i) DNA methylation,and ii) histone modifications. DNA methylation might give scientists a link to the rise in obesity.The study aimed to investigate the effect of sugars used as sweeteners in sugar-sweetened beverages (SSB) on DNA methylation in a Caco-2 cell line in vitro. Four major objectives were pursued in the study which were to:(1) stimulate the Caco-2 cells with varying concentrations of sugar sweeteners and assess the morphological changes of the cells; (2) evaluate the cytotoxicity of different concentrations of the sugar sweetener on the Caco-2 cell line using the Alamar blue and LDH assay; (3) obtain genomic DNA from the treated Caco-2 cell line and perform bisulfite conversion and rest; and (4) amplify the WT1, MEG3, TNFRSF9, ATP10A, and CD44 obesity-associated genes and ascertain their degree of methylation. Caco-2 cells were stimulated with sugar sweeteners at varying concentrations (low, medium and high) for an incubation period of 62 days,and images of the cells were captured for morphological characterisation. The incubation condition entailed cells plated in a 12 or 96 well plate, incubated in a humidified 5% CO2 incubator at 37 °C and there is nutrient renewal every three days.Alamar blue, a cell proliferation colourimetric assay and lactate dehydrogenase assays (LDH), a homogenous membrane fluorimetric assay were used for the cytotoxicity studies. The results of the characterisation showed that different concentrations of sugar sweeteners affected the morphology of the cells as the incubation period progressed. The cytotoxicity results of both LDH and Alamar blue depicted low concentration of sweeteners that had low-to-moderate toxicity and the medium and high concentration of the sweeteners had a moderate to high toxicity on the Caco-2 cells. DNA from the Caco-2 cells was extracted. Techniques used to study DNA methylation such as bisulfite conversion, PCR amplification and restriction enzymes that have differential sensitivity to 5-methyl-cytosine were performed. The quality of DNA extracted was good. The bisulfite conversion was conducted andno amplification was observed, as a contingency plan Normal PCR was performed to amplify the CpG islands, and there was amplification. In conclusion, the study showed that a low concentration of a sugar sweetener (fructose: glucose) used in beverages had low toxicity to the Caco-2 cell line and prolonged exposure of the low concentration might have an adverse effect on the cells' morphology. At medium concentrations, the sugar sweetener used in beverages had medium toxicity to Caco-2 cells; prolonged exposure may lead to morphological changes. These findings indicated that control of dietary glucose intake is an important strategy in combating the development of obesity and type-2 diabetes. DNA methylation could not be established.

Thesis (M. A. (Physiology)) -- University of Limpopo, 2022 / Background: Metabolic syndrome (MetS) is amongst the underlying causes of mortality and morbidity globally. However, lifestyle habits such as frequent consumption of sugar-sweetened beverages (SSBs) contributes to its onset. The study was aimed at investigating the association between MetS and SSBs intake among Ellisras rural youth. Additionally, to find the best obesity indices to predict MetS. Methods: The current study included a total of 593 Ellisras rural youth, aged 22 to 30 years (289 males and 304 females). Anthropometric measurements, blood pressure (BP), and biochemical assessment were taken using standards procedures. A validated 24hrs recall questionnaire and food manuals were used to collect SSBs data. Binary logistic regression was applied to determine the association between SSBs intake and MetS components for the adjusted model. Confirmatory factor analysis was used to test the best single-factor models to predict MetS on commonly selected obesity indices. Results: The SSBs quartile 4 was associated with a high risk of high fasting blood glucose (FBG) for adjusted (OR=2.32; CI=1.15-4.70; p<0.05) and unadjusted (OR=2.34; CI=1.16-4.73; p<0.05) models were a significant linear trend (p for trend=0.049) in males was found. Low risk of reduced high density lipoprotein cholesterol (HDL-C) was associated with the second and fourth SSBs quartiles for unadjusted ((OR=0.40; CI=0.18-0.85; p<0.05; OR=0.37; CI=0.13-0.80; p<0.05) respectively and adjusted model (OR=0.40; CI=0.18-0.85; p<0.05; OR=0.37; CI=0.17-0.80; p<0.05) respectively in females. Moreover, the fourth SSBs quartile was likely to decrease the risk of high triglycerides (TG) for unadjusted (OR=0.12; CI=0.01-0.87; p<0.05) and adjusted (OR=0.10; CI=0.01-0.83; p<0.05) models were the significant linear trend (p= trend 0.006) was observed also in females. There was a significant linear trend association between SSBs quartiles consumption and high TG in males and high waist circumference (WC) in females, but logistic regression analysis didn’t depict any significant association (p>0.05). In males, single model fit built based on WC (comparative fit index (CFI)=1.00; turker lewis index (TLI)=1.05; RMSEA=0.00; akaike information criterion (AIC)=-2680) and waist to height ratio v (WHtR) (RMSEA=0.00, CFI=1.00; AIC=-2662, TLI=1.05;) suggested a better fit index as compared to body mass index (BMI) and neck circumference (NC). Among females, a single model fit built on NC obtained a better fit index (RMSEA=0.05, CFI=0.90, and AIC= -429.21, TLI=0.71). Conclusion: In this study, there was an association between SSBs consumption and some MetS components (high TG, reduced HDL-C, and high FBG). Obesity indices including WHtR, NC, and WC were the best predictors of MetS. Future studies are recommended to further investigate the association of the risk of MetS and the consumption SSBs and the best obesity indices to predict MetS to assist in efforts to help curb MetS and related risk factors in rural areas of South Africa.

Introduction: Little is known about dietary patterns among individuals with type 2 diabetes mellitus (T2DM) in Peru. This study aimed at determining whether there is association between glucosa metabolism disorder and consumption of fruits, vegetables and sweetened beverages. Material and Methods: Secondary analisis of a population-based cross-sectional study conducted in Tumbes, a región in northern Peru. The outcomes variable were consumption of fruits, vegetables and sweetened beverages, defined by self-report, whilst the exposure was glucose metabolism disorder status (euglicemic, with T2DM bit not aware of diagnosis, and with T2DM and aware of diagnosis), defined by the oral glucose tolerance test. To assess the associations of interest, Poisson regression models with robust variance were created, and prevalence ratios (PR) and 95% confidence intervals (95% CI) were reported. Results: A total of 1607 individuals, mean age 48.2 (SD:10.6); and 809 (50.3%) females, was enrolled. The prevalence of T2DM was 11.0% (95%CI: 9.5%-12.6%), and out of them, 105 (59.7%) had previous diagnosis. Only 213 (13.3%) reported consuming sweetened beverages > once/week, whilst 409 (25.5%) and 736 (45.8%) reported consuming vegetables and fruits, respectively. Those with previous T2DM diagnosis had lower probability of consuming sweetened beverages (sometimes vs. never: PR=0.57; 95%CI: 0.41-0.78, and >once/week vs. never PR=0.39; 95%CI: 0.18-0.85). Both the consumption of fruits and vegetables were similar among those with and without previous T2DM diagnosis. Conclusions: Compared to euglycemic subjects, individual with previous T2DM diagnosis had lower consumption of sweetened beverages, but such association was not present among those with T2DM but without previous diagnosis. Fruits and vegetables consumption were not different between the different glucose metabolism disorder categories. / Introducción: Poco se conoce sobre los patrones de dieta de individuos con diabetes mellitus tipo 2 (DM2) en Perú. El objetivo del presente estudio fue determinar si existe asociación entre la alteración del metabolismo de la glucosa y ciertos patrones de dieta (consumo de bebidas azucaradas, verduras y frutas). Materiales y métodos: Análisis secundario de un estudio poblacional de tipo transversal realizado en Tumbes, en el norte del Perú. Las variables resultado fueron consumo de bebidas azucaradas, consumo de verduras y consumo de frutas, definidas por autorreporte; mientras que la exposición fue la alteración del metabolismo de la glucosa (euglicémico, con DM2 pero sin diagnóstico previo, y con DM2 y diagnóstico previo), basado en la prueba de tolerancia oral a la glucosa. Para evaluar las asociaciones de interés se crearon modelos de regresión de Poisson con varianza robusta y se reportaron razones de prevalencia (RP) e intervalos de confianza al 95% (IC 95%) Resultados: Un total de 1607 individuos, media de edad de 48 , 2 (DE: 10,6), y 809 (50,3%) mujeres, fueron enrolados. La prevalencia de DM2 fue de 11,0% (IC95%: 9,5% -12,6%), y de ellos, 105 (59,7%) tuvieron diagnóstico previo. Solo 213 (13,3%) reportaron consumir bebidas azucaradas> 1 vez / semana, mientras que 409 (25,5%) y 736 (45,8%) reportaron consumir verduras y frutas en forma casi diaria, respectivamente. Aquellos con diagnóstico previo de DM2 tuvieron menor probabilidad de consumir bebidas azucaradas (algunas veces vs.Nunca: RP = 0,57; IC95: 0,41-0,78 y> 1 vez / semana vs.Nunca: RP = 0,39 ; IC95%: 0,18-0,85). Ni el consumo de frutas ni el de verduras fue mayor en aquellos con o sin diagnóstico previo de DM2. Conclusiones: Comparados con los euglicémicos, los individuos con diagnóstico previo de DM2 tuvieron un menor consumo de bebidas azucaradas, pero dicha asociación no estuvo presente en aquellos con DM2 sin diagnóstico previo. El consumo de frutas y verduras no fue diferente entre las categorías de alteración del metabolismo de la glucosa estudiadas. / Tesis

There are many different types of non-alcoholic beverages (NAB) available in the United States today compared to a decade ago. Additionally, the needs of beverage consumers have evolved over the years centering attention on functionality and health dimensions. These trends in volume of consumption are a testament to the growth in the NAB industry. Our study pertains to ten NAB categories. We developed and employed a unique cross-sectional and time-series data set based on Nielsen Homescan data associated with household purchases of NAB from 1998 through 2003. First, we considered demographic and economic profiling of the consumption of NAB in a two-stage model. Race, region, age and presence of children and gender of household head were the most important factors affecting the choice and level of consumption. Second, we used expectation-prediction success tables, calibration, resolution, the Brier score and the Yates partition of the Brier score to measure the accuracy of predictions generated from qualitative choice models used to model the purchase decision of NAB by U.S. households. The Yates partition of the Brier score outperformed all other measures. Third, we modeled demand interrelationships, dynamics and habits of NAB consumption estimating own-price, cross-price and expenditure elasticities. The Quadratic Almost Ideal Demand System, the synthetic Barten model and the State Adjustment Model were used. Soft drinks were substitutes and fruit juices were complements for most of non-alcoholic beverages. Investigation of a proposed tax on sugar-sweetened beverages revealed the importance of centering attention not only to direct effects but also to indirect effects of taxes on beverage consumption. Finally, we investigated factors affecting nutritional contributions derived from consumption of NAB. Also, we ascertained the impact of the USDA year 2000 Dietary Guidelines for Americans associated with the consumption of NAB. Significant factors affecting caloric and nutrient intake from NAB were price, employment status of household head, region, race, presence of children and the gender of household food manager. Furthermore, we found that USDA nutrition intervention program was successful in reducing caloric and caffeine intake from consumption of NAB. The away-from-home intake of beverages and potential impacts of NAB advertising are not captured in our work. In future work, we plan to address these limitations.

Introducción: El consumo de bebidas azucaradas (SSB) se ha relacionado con un incremento en el Índice de Masa Corporal (IMC), lo cual sería especialmente preocupante en poblaciones con un potencial de exposición prolongada, tales como estudiantes. Objetivo: Evaluar la relación entre el consumo calórico proveniente de SSB medido mediante el cuestionario Bevq-15 e IMC en estudiantes de carreras de ciencias de la salud de una universidad peruana. Materiales y métodos: Estudio transversal analítico en base a la medición del consumo calórico de 15 bebidas mediante la administración del cuestionario BEVQ-15 y la toma de medidas antropométricas a universitarios durante 2018 - 2019. Se evaluó la asociación cruda y ajustada usando modelos de regresión lineal. Resultados: Se incluyó a 350 personas. La mediana fue de 21 años y el 58.29% fueron mujeres. La mediana del IMC fue de 24.00 (21.75 - 26.90). El consumo promedio de calorías provenientes de bebidas azucaradas fue de 25.35 kcal/día. Se asoció un IMC menor con el sexo femenino (p<0.001), la carrera de nutrición (p=0.002) y nunca haber consumido tabaco (p=0.027). Se asoció un IMC mayor a la dislipidemia (p=0.014) y a un mayor consumo de calorías diarias provenientes de SSB (p<0.001). En el análisis multivariado se encontró asociación significativa entre el consumo de calorías provenientes de SSB y el IMC, ajustado por edad, sexo y tabaquismo (coeficiente β: 0.68; IC95% 0.04-1.33; p=0.037). Conclusiones: Se encontró asociación entre el consumo de calorías derivadas de SSB y un mayor IMC. Se debe impulsar intervenciones destinadas a la disminución de su consumo en estudiantes. / Introduction: The consumption of sugar sweetened beverages (SSB) has been related to an increase in the Body Mass Index (BMI), which would be especially worrisome in populations with a prolonged exposure potential, such as students. Objective: To evaluate the relationship between the caloric intake from SSB measured by the Bevq-15 questionnaire and BMI in health sciences students at a Peruvian university. Materials and methods: Cross-sectional analytical study based on the measurement of the caloric consumption of 15 beverages based on the administration of the BEVQ-15 questionnaire and the measurement of college students’ anthropometric measurements during 2018-2019. The crude and adjusted association were evaluated using linear regression models. Results: We enrolled 350 participants. The median age was 21 years and 58.29% were women. The median BMI was 24.00 (21.75 - 26.90). The average consumption of calories from SSB was 25.35 kcal/day. A lower BMI was associated with the female sex (p <0.001), the nutrition career (p = 0.002) and never having used tobacco (p = 0.027). A higher BMI was associated with dyslipidemia (p = 0.014) and a greater consumption of daily calories from SSB (p <0.001). In the multivariate analysis, a significant association was found between the consumption of calories from SSB and BMI, adjusted for age, sex and smoking (β coefficient: 0.68, 95% CI 0.04-1.33, p = 0.037). Conclusions: An association was found between the consumption of calories derived from SSB and a higher BMI. Interventions aimed at reducing student consumption should be promoted. / Tesis

<p>  </p> <p>The prevalence of obesity and type 2 diabetes has increased worldwide over the last decades. Sugar-sweetened beverages are especially problematic in the development of obesity and type 2 diabetes. Although the proportion of Americans consuming SSB regularly has been steadily declining, added sugar intake still remains above recommendations by the Dietary Guidelines for Americans and World Health Organization. However, alternatives to SSB exist on the market. For many years, the primary alternatives to SSB were low-calorie sweetened beverages, with sweetness replacers such as aspartame or sucralose. In recent years, options that are less sweet or unsweetened (instead of alternatively sweetened) have become increasingly available. These less-sweet beverages are available in similar packaging and at similar cost as SSB. Thus, these less-sweet beverages may be ideal options to reduce added sugar in the diet. However, few studies have tested switching consumers from SSB to less-sweet beverages (rather than low-calorie sweetened beverages or plain water), and thus the acceptability and implications of this dietary change are minimally documented. In this work, we tested less sweet soda-like beverages and unsweetened sparkling waters for potential to replace SSB. First, we showed that small reductions in sweetness in cola-flavored sodas are noticeable to individuals, meaning that any switch from SSB to less-sweet options will likely need to be overt to the consumer. Next, we conducted a 12-week intervention with adolescents, which showed that replacing SSBs with unsweetened sparkling waters leads to increased liking of less-sweet sodas and shifts in the ideal level of sweetness towards lower sugar concentrations. Building on these results, our final study shows that even just 2 weeks is enough time to induce these changes in acceptance of less sweetness in sodas, if a consumer prefers the higher concentrations of sugar at the beginning of the intervention (a “sweet liker”). Future studies are needed to evaluate how replacing SSB with less sweet options, leading to shifts in sweetness preference, might influence overall diet and risks for diet-related chronic diseases.</p>