Browsing by Subject "Nutrition"

Background: The prevalence of childhood obesity in the US is high; this includes young children living in low-income households. Many of these children are served by the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Digital interventions that target caregivers enrolled in WIC show potential for childhood obesity prevention. This study aims to describe 1) the formative research for developing a pilot digital intervention focused on improving diet quality and increasing redemption of WIC-approved foods, and 2) the challenges faced in developing the intervention due to the COVID-19 pandemic. Methods: In-depth interviews were conducted with 13 WIC caregivers. Interviews were recorded and transcribed. Transcripts were coded using structural themes, and analyzed using NVivo 12. A data reduction table was created afterwards and inter-coder reliability was achieved. Results: Fourteen themes clustered into four domains. The first domain centered on how caregivers perceived healthy eating. Definitions for healthy and unhealthy eating depended on the source of nutrition information and contributed to practices of healthy eating. The second domain described the caregiver’s purchasing of WIC-approved foods. Fruits, vegetables, milk, cheese, and eggs were the most purchased foods, while yogurt and peanut butter were the least purchased foods. The biggest facilitator to purchasing WIC-approved foods was taste preferences, and the biggest barrier was picky eating. The third domain described WIC’s helpfulness in healthy eating promotion; caregivers believed in the latter and provided suggestions for WIC to help them further. The last domain described the text messaging preferences. It showed that WIC caregivers believed that a text messaging program would help them eat healthier. They preferred receiving text messages weekly, in the morning, and receiving recipes and tips. The COVID-19 pandemic affected implementation of the intervention through disrupting contact with stakeholders, the recruitment process, and the completion of surveys used for intervention feasibility analysis. Conclusions: Future studies should consider utilizing and documenting formative research to guide intervention development. Comprehensive protocols for contacting stakeholders, recruitment, and follow up are important proactive tools during implementation.

Nearly all animals live in environments with fluctuations in nutrient availability. The ability to sense and respond to these changes is essential for survival. Nutrition impacts physiology immediately, but can also have long-lasting effects across generations. The nematode Caenorhabditis elegans is particularly well-adapted to thrive in conditions of variable food availability. Here we find that starvation responses in C. elegans are largely independent of the larval stage at which worms experience starvation. Starvation in worms results in shrinkage, delayed growth upon recovery, and ultimately death. In order to adapt to starvation, metabolism is dramatically altered. At a gross level, this can be seen in a reduction of mitochondrial genomes and a more fragmented network of mitochondria.

Insulin-like signaling is a key cell signaling pathway controlling nutrient responses. We interrogate the role of insulin-like signaling in regulation of the acute starvation response. We show that daf-16/FoxO restructures carbohydrate metabolism by driving carbon flux through the glyoxylate shunt and gluconeogenesis and into synthesis of trehalose, a disaccharide of glucose. Trehalose is a well-known stress protectant, capable of preserving membrane organization and protein structure during abiotic stress. Metabolomic, genetic, and pharmacological analyses confirm increased trehalose synthesis and further show that trehalose not only supports survival as a stress protectant, but also serves as a glycolytic input. Further, we provide evidence that metabolic cycling between trehalose and glucose is necessary for this dual function of trehalose. This work demonstrates that daf-16/FoxO promotes starvation resistance by shifting carbon metabolism to drive trehalose synthesis, which in turn supports survival by providing an energy source and acting as a stress protectant.

In addition to acute changes in response to the nutrient environment, effects can persist intergenerationally. Maternal effects of environmental conditions produce intergenerational phenotypic plasticity. Adaptive value of these effects depends on appropriate anticipation of environmental conditions in the next generation, and mismatch between conditions may contribute to disease. However, regulation of intergenerational plasticity is poorly understood. Dietary restriction (DR) delays aging but maternal effects have not been investigated. We demonstrate maternal effects of DR in the roundworm C. elegans. Worms cultured in DR produce fewer but larger progeny. Nutrient availability is assessed in late larvae and young adults, rather than affecting a set point in young larvae, and maternal age independently affects progeny size. Reduced signaling through the insulin-like receptor daf-2/InsR in the maternal soma causes constitutively large progeny, and its effector daf-16/FoxO is required for this effect. nhr-49/Hnf4, pha-4/FoxA, and skn-1/Nrf also regulate progeny-size plasticity. Genetic analysis suggests that insulin-like signaling controls progeny size in part through regulation of nhr-49/Hnf4, and that pha-4/FoxA and skn-1/Nrf function in parallel to insulin-like signaling and nhr-49/Hnf4. Furthermore, progeny of DR worms are buffered from adverse consequences of early-larval starvation, growing faster and producing more off- spring than progeny of worms fed ad libitum. These results suggest a fitness advantage when mothers and their progeny experience nutrient stress, compared to an environmental mismatch where only progeny are stressed. This work reveals maternal provisioning as an organismal response to DR, demonstrates potentially adaptive intergenerational phenotypic plasticity, and identifies conserved pathways mediating these effects.

Background: Alcohol consumption is a major risk factor for several adverse health effects globally and is associated with a high disease burden of malnutrition in Tanzania. This study aims to: 1) assess the practicality and effectiveness of mid-upper arm circumference (MUAC) as a feasible bedside measure to detect malnutrition among adult and pediatric patients, 2) evaluate the association between alcohol use and nutritional status among adult injury patients and 3) qualitatively identify social determinants of malnutrition in Tanzania. Methods: This mixed-method study was conducted in Kilimanjaro Christian Medical Centre. Receiver Operating Characteristic (ROC) curves and logistic regression were used for quantitative data on alcohol use, body mass index (BMI), MUAC. Thematic approach was used for qualitative data on perspectives on alcohol use and its interactions with malnutrition. Results: MUAC cut-offs were determined at < 25.5 cm (BMI < 16 kg/m2) for severely underweight, < 28 cm (BMI < 18.5 kg/m2) for underweight, ≥ 30.5 cm (BMI ≥ 25 kg/m2) for overweight, ≥ 33 cm (BMI ≥ 30 kg/m2) for obese. The association between alcohol use and malnutrition (MUAC < 25.5 cm) was statistically significant. Qualitative results helped explain the association between alcohol use and malnutrition. Conclusions: MUAC is an effective tool to detect adult malnutrition to inform clinical practice in Tanzania. Polarizing attitudes towards drinking revealed by qualitative data suggested the need for alcohol awareness campaigns. Food assistance programs are needed to reduce the risk of malnutrition among vulnerable populations.

Background: Appropriate nutrition during early life is essential for optimal growth and development. China has seen a drastic improvement in child nutrition over the past few decades with decreased rates of stunting, wasting and undernutrition. However, there are wide gaps in the nutritional status of young children and preschoolers in rural and urban areas, which is a major public health concern. Currently, there is limited understanding about dietary intake of young children and the rural-urban gap in China, especially in the years after 2000. Therefore, the aims of this study were to examine trends in dietary intake of children at 2-6 years of age using data from the Chinese Health and Nutrition Surveys (CHNS) collected in 2000, 2004, 2006, 2009 and 2011 and to conduct interviews from key stakeholders in China to gather their perspectives and insights regarding child nutrition improvement in China.

Methods: Data obtained from the China National Nutrition and Health Survey (CNNHS) and Global Burden of Diseases, Injuries, and Risk Factors (GBD) database were used to describe the trend of child nutritional status in last 20 years from 1992 to 2016. Anthropometric nutritional indicators including stunting, wasting, underweight, overweight and obesity were presented in bar graphs and tables.

In-depth interviews were conducted with 23 stakeholders whose work involved child nutrition at national levels, as well as two provinces in Yunnan and Hubei. The interviews addressed topics about the changes and the current status of child undernutrition, as well as major tasks for child nutrition improvement. The qualitative analysis for the in-depth-interviews consisted of thematic analysis. The interviews were conducted in Mandarin. Coding and charting were processed in Chinese text using MAXQDA version 12. The final thematic framework and insightful quotations were translated into English.

The quantitative analysis used the individual level, consecutive 3-day 24-hour dietary recall data from five waves of the China Health and Nutrition Surveys (CHNS) in 2000, 2004, 2006, 2009 and 2011. Energy, macronutrient intakes (carbohydrate, protein, and fat) and food group intakes of whole grains, vegetables, fruits, meat and other protein sources (i.e., fish and egg), dairy products and snacks were estimated using data from Chinese Food Composition Tables (2002)1. These results were presented by survey year, age group, gender, and region (rural/urban areas). ANOVA, Chi-square test or t-test were used to examine differences between subgroups. Statistical analyses were performed using SAS version 9.4 (SAS Institute, Cary, NC).

Results: Impressive declines were reported in the prevalence of child stunting (35.8% to 8.1%), underweight (19.8% to 3.2%) and wasting (3.7% to 2.4%) from 1992 to 2012 in China, while an upward trend of overweight (6.5% to 8.4%) and obesity (2.7% to 3.3%) was observed in children under 6 years old from 2002 to 2012 in the CNNHS database. Most interview respondents expressed concerns about the increasing prevalence of childhood obesity, and the urgency of action for alleviating undernutrition among children living in poverty-stricken areas. The interview respondents from the child nutrition-related governmental departments in Hubei and Yunnan province stressed the necessity of enlarging the scale of the coverage of governmental child nutrition improvement programs in poverty-stricken rural areas. The average energy and macronutrients intake of children 2-6 years of age in the CHNS increased from 2000 to 2009 with a slight decrease in 2011. Among both rural and urban children, the percent energy from fat increased from 2000 to 2011 and exceeded 30% of energy intake. In general, the percentage of these children who consumed vegetables, meat and protein from fish and eggs, and dairy products increased from 2004-2011, and significant dietary intake disparities of protein source foods, such as dairy products were observed between rural and urban areas (p < 0.05) with lower intakes among children in rural areas.

Conclusions: From the years 2000 to 2011, the nutritional status and diet quality among urban and rural young children in China has undergone significant improvement. Also, young children in China are undergoing a remarkable nutrition transition characterized by a high energy intake from fat and low energy intake from carbohydrates. Both urban and rural children are facing the threat brought about by this nutrition transition, and this may lead to the increasing burden of child overweight. Further, dietary disparities still exist. Governmental commitment should be devoted to helping vulnerable, marginalized populations living in poor rural areas in China to further reduce undernutrition, and strategic action targeted at reducing childhood overweight should be taken to control the increasing trend in obesity in both rural and urban areas.

AbstractBackground China has witnessed a rapid increase in the prevalence of diabetes and childhood obesity over the past decades with an alarming increase in free sugar consumption, especially through sugar-sweetened beverages (SSBs). However, there are no national policies on SSBs in China. Little is known about the acceptability, adaptability, and scalability of policies on SSB consumption in China. Therefore, this study aims to explore stakeholder perceptions on the introduction of SSB policies and implementation challenges in China, and draw policy implications from the information gained.

MethodsThis study design is adapted from a theoretical framework “Analyzing and addressing governance in sector operations”, with context analysis, qualitative interviews and stakeholder analysis. Semi-structured interviews were conducted with 37 stakeholders in Shanghai and Chongqing, China, including health commission officers, CDC officers, market regulation officers, academia, nutrition association, industries, and consumers (parents of children and adolescents).

Results Currently, there is a rising trend of SSB consumption among children and adolescents in China, and the interviewed stakeholders were aware of the change in behaviors. Different stakeholders shared different understandings of the rising SSB consumption trends and conflicting prospects on whether SSB policies should be introduced in China. Besides, they also expressed different views on the choice of SSB policies, effectiveness, acceptability, and scalability. Most policy makers and nutrition experts agreed that health education is the most important and appropriate strategy to control SSB consumption by Chinese children and adolescents, and market regulation officers believe stricter policies such as taxes and mandatory front-of-pack labelling would be effective. On the other hand, industry stakeholders would prefer step-by-step policies including policies with multiple stages and voluntary labelling, wishing to create a better transition period for the market to respond. Furthermore, the interviewed consumers also observed the increasing trend of SSB consumption from their children. Some parents were aware of the health risk of excess SSB intake and believed in the positive impact of public health policy guidance, others would prefer the freedom to make their own choice as consumers and enjoy the sweet tastes of SSBs. In addition, perceived facilitators to the introduction of SSB policies include standard establishment or reform, the multi-sector collaboration of health, marketing, education departments and the industries, and step-by-step adaptation of SSB policies. Besides, potential challenges include responsibility distribution between different departments, resistance from industries, and consumer opposition.

ConclusionThis study examined the perceptions of SSB policy introduction among different Chinese stakeholders, including policy makers, nutrition experts, the industry and consumers. Although the SSB intake among Chinese children and adolescents is growing, interviewed stakeholders showed inadequate knowledge and awareness of SSB policies. Valid policy action on a national scale would require national standard reforms, as well as improving awareness of policy makers and the nutrition literacy of Chinese consumers. Future studies could conduct formative research and collect implementation evidence to better facilitate the establishment of SSB policies in China.

Background: Nutrition is a key determinant of pediatric cancer patient outcomes in sub-Saharan Africa. Accurately identifying pediatric cancer patients at risk of malnutrition remains a challenge. There is a need for a standardized nutritional screening tool, developed and validated in sub-Saharan Africa. Study aims: The aims of this study were to: 1) select candidate variables in the development of a nutritional screening from predictors associated with malnutrition in pediatric cancer patients and, 2) conduct a secondary data analysis estimating the prevalence of pediatric cancer in Uganda from cases presented at the Uganda Cancer Institute between January 1, 2017 and December 31, 2019. Methods: This study is a longitudinal hospital-based study, carried out at the Bugando Medical Center in Tanzania and Uganda Cancer Institute in Uganda. The study enrolled clinically confirmed pediatric cancer patients (<18 years) at the study sites. Measures of interest include: nutritional status, symptom duration, abdominal distention, anthropometric measures such as height, weight, mid-upper arm circumference, abdominal circumference, triceps skinfold thickness, and clinical characteristics such as serum albumin, mean corpuscular volume, and protein. Logistic regression models examined predictors of nutritional status in pediatric cancer patients. Lastly, geospatial analysis estimated the prevalence and examined the country-wide distribution of the pediatric cancers presented at the Uganda Cancer Institute between 2017 and 2019. Results: The sample of 77 pediatric cancer patients enrolled at the two study sites ranged from 1 to 17 years old. Solid tumor malignancies like Wilms tumor comprise of 40% of all diagnoses. 60% of cancer patients were malnourished at baseline. The strongest predictors of nutritional status were mid-upper arm circumference (AOR 0.52, 95% CI: 0.31 – 0.87), abdominal circumference (AOR 1.38, 95% CI: 1.16 – 1.65) and serum albumin (AOR 0.73, 95% CI: 0.62 - 0.86). Secondary analysis of the Uganda Cancer Institute registry shows 11607 patients with confirmed cancer diagnosis between 2017 and 2019. Acute lymphoblastic leukemia (31.4%) is the most common cancer diagnosis, followed by Wilms tumor (19.1%), rhabdomyosarcoma (9.4%) and Burkitt’s lymphoma (6.9%). Blood cancers are most common cancer types, of them the most frequent cases being leukemia (37%). 2018 saw the highest number of cancer presentations within the study timeframe. Conclusions: The results show abdominal circumference, serum albumin, and muac are candidate variables in developing a nutritional screening tool for pediatric cancer patients in SSA. Blood and solid cancers are prevalent in Uganda; thus, a customized nutritional screening tool is much needed.

Developmental physiology is very sensitive to nutrient availability. For instance, in the nematode C. elegans, newly hatched L1-stage larvae require food to initiate postembryonic development. Despite the essential role of food in C. elegans development, the contribution of food perception versus ingestion on physiology has not been delineated. We used a pharmacological approach to uncouple the effects of food (bacteria) perception and ingestion in C. elegans. Perception was not sufficient to promote postembryonic development in L1-stage larvae. However, L1 larvae exposed to food without ingestion failed to develop upon return to normal culture conditions, instead displaying an irreversible arrest phenotype. Inhibition of gene expression during perception rescued subsequent development, demonstrating that the response to perception without feeding is deleterious. Perception altered DAF-16/FOXO subcellular localization, reflecting activation of insulin/IGF signaling (IIS). However, genetic manipulation of IIS did not modify the irreversible arrest phenotype caused by food perception, revealing that wild-type function of the IIS pathway is not required to produce this phenotype and that other pathways affected by perception of food in the absence of its ingestion are likely to be involved. Gene expression and Nile red staining showed that food perception could alter lipid metabolism and storage. We found that starved larvae sense environmental polypeptides, with similar molecular and developmental effects as perception of bacteria. We conclude that actual ingestion of food is required to initiate postembryonic development in C. elegans. We also conclude that polypeptides are perceived as a food-associated cue in this and likely other animals, initiating a signaling and gene regulatory cascade that alters metabolism in anticipation of feeding and development, but that this response is detrimental if feeding does not occur.

The C. elegans insulin-like signaling network supports homeostasis and developmental plasticity. The genome encodes 40 insulin-like peptides and one known receptor. Feedback regulation has been reported, but the extent of feedback and its effect on signaling dynamics in response to changes in nutrient availability has not been determined. We measured mRNA expression for each insulin-like peptide, the receptor daf-2, components of the PI3K pathway, and its transcriptional effectors daf-16/FOXO and skn-1/Nrf at high temporal resolution during transition from a starved, quiescent state to a fed, growing state in wild type and mutants affecting daf-2/InsR and daf-16/FOXO. We also analyzed the effect of temperature on insulin-like gene expression. We found that most PI3K pathway components and insulin-like peptides are affected by signaling activity, revealing pervasive positive and negative feedback regulation at intra- and inter-cellular levels. Reporter gene analysis demonstrated that the daf-2/InsR agonist daf-28 positively regulates its own transcription and that the putative agonist ins-6 cross-regulates DAF-28 protein expression through feedback. Our results show that positive and negative feedback regulation of insulin-like signaling is widespread, giving rise to an organismal FOXO-to-FOXO signaling network that supports homeostasis during fluctuations in nutrient availability.

L1 arrest (or "L1 diapause") is associated with increased stress resistance, supporting starvation survival. Loss of the transcription factor daf-16/FOXO results in arrest-defective and starvation-sensitive phenotypes. We show that daf-16/FOXO regulates L1 arrest cell-nonautonomously, suggesting that insulin/IGF signaling regulates at least one additional signaling pathway. We used mRNA-seq to identify candidate signaling molecules affected by daf-16/FOXO during L1 arrest. dbl-1/TGF-β, a ligand for the Sma/Mab pathway, daf-12/NHR, and daf-36/oxygenase, an upstream component of the daf-12 steroid hormone signaling pathway, were up-regulated during L1 arrest in a daf-16/FOXO mutant. Using genetic epistasis analysis, we show that dbl-1/TGF-β and daf-12/NHR steroid hormone signaling pathways are required for the daf-16/FOXO arrest-defective phenotype, suggesting that daf-16/FOXO represses dbl-1/TGF-β, daf-12/NHR and daf-36/oxygenase. The dbl-1/TGF-β and daf-12/NHR pathways have not previously been shown to affect L1 development, but we found that disruption of these pathways delayed L1 development in fed larvae, consistent with these pathways promoting development in starved daf-16/FOXO mutants. Though the dbl-1/TGF-β and daf-12/NHR pathways are epistatic to daf-16/FOXO for the arrest-defective phenotype, disruption of these pathways does not suppress starvation sensitivity of daf-16/FOXO mutants. This observation uncouples starvation survival from developmental arrest, indicating that DAF-16/FOXO targets distinct effectors for each phenotype and revealing that inappropriate development during starvation does not cause the early demise of daf-16/FOXO mutants. We show that daf-16/FOXO promotes developmental arrest cell-nonautonomously by repressing pathways that promote larval development.

The cholinergic system is intricately linked with hippocampal memory. As well, choline is anti-inflammatory in the brain and periphery (Terrando et al., 2011; Rivera et al., 1998). However, few have analyzed the anti-inflammatory properties of choline as an alternate means by which cholinergic manipulations affect hippocampal memory throughout the lifespan. The first aim of this dissertation work sought to determine if dietary choline supplementation protects against the deleterious effects of air pollution in the developing brain. Pregnant mice were given a high-choline diet (approximately 4.5x the choline chloride in the control diet) or a synthetic control diet. As well, dams were exposed to a series of diesel particulate (DEP) or saline vehicle sessions throughout pregnancy. Mice were sacrificed and tissues were collected on embryonic day 18. The activation state of microglia, identified by quantifying morphology using Iba1+ immunohistochemical staining, was examined in the dentate gyrus of the hippocampus (DG), the paraventricular nucleus (PVN) of the hypothalamus, the basolateral amygdala (AMY), and the parietal cortex (PCX). As expected, we found that DEP led to increased microglial activation in the fetal DG in males. Choline supplementation partially prevented this increase in activation. Interestingly, these effects were region-specific: the opposite pattern is seen in the PVN, and no significant diesel effect was seen in the AMY and PCX. These findings suggest that prenatal choline supplementation throughout pregnancy may protect the fetal hippocampus against the neuroinflammation associated with air pollution. To analyze whether the acute effects of dietary choline seen prenatally also occur in adulthood, adult dietary choline supplementation alongside the tibial fracture model of post-operative cognitive dysfunction (POCD) was used. POCD occurs when increased neuroinflammation due to peripheral surgery leads to impairments in cognition. Differences were found in almost hippocampal-dependent behavior, astrocytic activation, and cell proliferation. Differences were time point-specific. In the hippocampus, astrocytic activation, cell proliferation, and hilar granule cells all increased 1 day after surgery, and these increases were blunted by dietary choline. An increase in hippocampal young neurons was found 2 weeks after surgery. However, both were blunted by choline supplementation. At both time points assessed, tibial fracture impaired novel object recognition performance, and dietary choline rescued these impairments. As well, dietary choline supplementation did not mitigate the increase in anxiety-related behavior – specifically implicating hippocampal actions of the nutrient. Because the hippocampal-dependent memory impairment and rescue is not time point-specific, but the neural effects of tibial fracture are each specific to a certain timepoint, the mechanisms of behavior are likely different at each time point. Building upon aim 2, aim 3 explores if perinatal choline supplementation can act via “programming” of the neuroimmune system in development to prevent POCD in adulthood. Perinatal choline supplementation prevented POCD and neuroinflammation due to peripheral surgery, but did not protect against increases in young neurons or hilar neurons. Perinatal choline nutrition, in addition to its already-known neuroprotection, is additionally protective against POCD and its associated neuroinflammation in adulthood. Taken together, this body of work concludes that dietary choline supplementation at various administration dates is protective in neuroinflammatory models in behavior and brain.

The human gut microbiome is increasingly recognized as having a causal or contributing role in a wide variety of diseases. While mechanisms by which the microbiome contributes to or triggers disease processes are myriad, short-chain fatty acid (SCFA) production has been found to be a powerful regulator of inflammation and gastrointestinal (GI) function, and may be central to the link between host and microbiota. Supplementing the diet with microbially accessible carbohydrates, termed prebiotics, is one mechanism by which SCFA production can be augmented or altered. While prebiotic therapies to increase SCFA in the gut have shown some promise in treating or preventing disease, treatment potential is limited by substantial inter-individual variation in responses to prebiotics. Determining the cause for this variation is necessary to develop treatment approaches that maximize patient responsiveness. Ultimately, tools to predict an individual’s response to a prebiotic and to guide treatment options must be developed. Here, I seek to understand the drivers of inter-individual and intra-individual variation in prebiotic response and to develop strategies to predict this response. In Chapter One, I introduce the human gut microbiome and its roles in maintaining host health and contributing to disease processes. I also present the existing evidence for substantial variation in SCFA productive response to prebiotic supplementation and highlight the need for a more nuanced understanding of the drivers of such variation. In Chapter Two, I explore the contributions of host factors and prebiotic choice to variation in SCFA production. This chapter introduces a novel in vitro fiber fermentation system, which is used throughout this thesis, and shows our methods validation of such. We find not only that host identity and prebiotic choice both impact SCFA production, but that the interaction of these terms is a significant contributor, introducing the possibility of the need for personalization. We then identify multiple host factors, including microbiota community composition and baseline SCFA metabolic state of stool, that explain some portion of inter-individual variation in prebiotic response. In Chapter Three, this relationship is further explored during the first in vivo triple-crossover prebiotic supplementation study. We supply 28 healthy adults with three different prebiotic supplements in a balanced and uniform crossover design, measuring SCFA as the primary outcome. This study makes the major contribution of quantifying the relative contribution of individual identity and prebiotic choice to butyrogenic response, and identifying individual as the vastly stronger predictor. We also identify habitual diet and baseline fecal SCFA concentrations as potential predictors of prebiotic efficacy. As a secondary analysis, we apply co-inertia analysis to draw associations between dietary choices and fecal SCFA metabolism. Together, these works highlight the need for personalization of prebiotic therapy and introduce potential biomarkers of responsiveness. In Chapter Four, we apply the concept of prebiotic therapy to graft-versus-host disease (GVHD) and show efficacy in a murine model. Importantly, we show that efficacy of prebiotics in this model of GVHD is dependent on the starting state of the microbiota, as observed through community composition analysis and functional in vitro fiber fermentation.

Background: The disease burden of malnutrition, anemia, malaria and helminth infections among school-aged children is rarely studied in low- and middle-income countries (LMICs) although these children are still at a high risk for these diseases compared with other more studied populations, such as pregnant women and children under 5 years old. Even in countries where the prevalence and trend of anemia and malnutrition are relatively well documented, few studies relate this to dietary factors, which are considered major contributors to anemia and malnutrition in most age groups. Aims: The aims of the study are (1) To determine the prevalence of anemia, malaria, helminth infections and malnutrition in a sample of 95 children, ages 6 to 14, attending primary schools in Naama Community, Uganda, and to observe and quantify school children's dietary patterns and daily nutrient intakes. (2) To find out the association between dietary factors and the risk of anemia and malnutrition. Methods: Measures included school-based, cross-sectional surveys, dietary assessments, anthropometric measurements and biological tests among school children. Photo-assisted 24-hour recall was used to collect daily nutrient intakes, combined with a Food Frequency Questionnaire (FFQ) to capture the dietary patterns. Anthropometrical and biochemical data was collected using standardized protocols. Socioeconomic data was obtained from parent surveys. Results: Ninety-five children in total were enrolled in all or some components of the study. The prevalence of anemia was low (3.2%), and all were mildly anemic. However, the prevalence of malaria and hookworm infections was relatively high, representing 12.9% and 24.4% of the studied population, respectively. In the studied children, 2.8% were underweight, 15.6% stunted and 1.3% thin, using criteria based on the WHO Growth reference. According to the WHO recommendations for nutrient intake, 80% of participants consumed inadequate energy from their daily diet, especially boys. Dietary fat intake was insufficient in 78% of the children. About 25% of the children had a low protein intake and 93% had low intakes of vitamin A. Calcium intake was low in school children's diet- 97.6% of children lacked of calcium. Inadequate vitamin C intake was less common, appearing in one out of three participants (29.1%). Matooke and posho, the most common local staple food, were the major sources for children's energy. Avocado, beans and matooke contributed to the highest fat, protein and vitamin A intake, respectively. Every participant reported consuming cereal/cereal products, roots/tubers/plantain, pulses/nuts, oil/oil-rich foods and fruits during the previous month, while almost one-fifth never consumed milk/dairy products. Vegetables were consumed by most of the respondents. Few (1.6%) of the respondents reported no animal source food in their diet. In general, children ate 3.81(SD: 0.99) out of all five meals in the area. Dinner was consumed by most of the participants (93.7%) while afternoon tea was the least consumed meal and was skipped by half of the childrenNo significant association between dietary factors and anemia were found, mainly due to the small sample size and low prevalence of disease. None of the dietary factors of primary interest were found to be associated with children's Hb concentration, but secondary analysis found the frequency of eating oranges was a protective factor for higher Hb concentration (P=0.015). The association between diet and stunting was not significant, except children who had low dietary fat intakes had a lower risk of being stunted compared with those had adequate fat consumption (OR=0.27, P=0.046). Conclusions: Malaria and helminth infections, but not anemia, in this cohort of school children is relatively high. Stunting was the most prevalent type of malnutrition. Most of the nutrients studied were not adequate in children's diets. The dietary pattern in this sample of children was primarily high in carbohydrates from staple foods and a minimal intake of fat and protein from animal sources. Children generally ate four meals per day. Dietary factors do not explain anemia and stunting in this population.

*Designated as an Exemplary Master's Project for 2014-15*

Background: Exclusive breastfeeding (EBF) in Kenya is on the rise, but there is still room for improvement. Current literature demonstrates that fathers have a positive influence on breastfeeding initiation, duration, and exclusivity. Yet there is a lack of information on paternal support in Kiambu County and Kenya, as a whole. This study aimed to explore fathers’ experiences with fatherhood, their perspectives and narratives on EBF, and the ways they support their partners through EBF for 6 months.

Methods: The study took place in three public, government hospitals in Kiambu County, Kenya. Two qualitative research methods were used to address the study aims: in-depth interviews and qualitative story completion. Data was analyzed using a rigorous process of applied thematic analysis.

Results: Fathers in this study described fatherhood as a challenging, but rewarding experience. Participants articulated positive sentiments towards EBF and had varying levels of knowledge on its benefits. Fathers described that they supported their partners by providing a nutritious diet and financial resources, helping with household chores, and facilitating childcare. Finally, the findings also illuminated evident gaps in paternal knowledge on EBF and the lack of father-centered information at public health facilities. Conclusions: This research established a baseline understanding of paternal support for a specific subgroup of fathers in Kiambu County, Kenya. Future research can further these findings by building a more representative, holistic picture of paternal support in Kenya. This will provide the necessary insights for designing context-specific educational interventions and programs targeting fathers in Kenya.

Abstract

Background: Rates of childhood overweight and obesity have increased dramatically across Latin America in recent years. In Honduras, the problem is more common among children of upper and middle socio-economic status (SES). Evidence suggests that television advertising of high-energy-density (HED) foods may be associated with increased rates of childhood overweight and obesity.

Objective: The purpose of this study was to characterize the advertising of foods during television programming that targets school-age children in Honduras.

Methods: Content analysis was performed on four different television stations accessible to children in Honduras, including one broadcast station and three cable networks. Programming for each station was observed and recorded for one complete week, during after-school hours (defined as 1:30 pm to 5:30 pm, Monday through Friday). Eighty hours of programming were recorded and analyzed. Foods were categorized as being high in energy density or not (HED or non-HED).

Results: A total of 2271 advertisements aired during the observation period; roughly half of these (49.3 percent) were product advertisements. Of the 1120 product advertisements, 397 marketed food-related products. Of these, 69.8 percent promoted HED foods. Children were targeted in the vast majority of advertisements for HED foods (92.1 percent). All of these foods were advertised on cable networks; none of the advertisements for HED foods were aired on broadcast television.

Conclusion: Cable television during after-school hours in Honduras included a high percentage of advertisements for HED foods. This may promote consumption of these foods by children, putting them at greater risk for overweight and obesity.

The prevalence of diabetes is on the rise, thus imposing a huge burden on our society. In addition to genetic and environmental risk factors, obesity strongly predicts the development of diabetes. Owing to the strong correlation between saturated fat and fructose intake and the incidence of metabolic diseases and obesity, dietary intervention is one of the common management strategies to control obesity and diabetes. Although there are still contentious debates on whether a low-fat or low-carbohydrate diet is beneficial to metabolic health, less is known about the interaction between lipid and carbohydrate metabolism. One of the overlooked interactions is how fat intake modulates fructose metabolism.

The effects of high-fat intake were first studied in mouse models. Coupled with fructose stable isotopic tracing, we profiled the fructose metabolism in various tissues among mice fed with either a high-fat diet or a control diet. We also surveyed the fructose-derived metabolites in the circulation to establish the systematic perturbations of fructose metabolism by the high-fat diet. We unveiled that a high-fat diet potentiates intestinal fructose metabolism and the production of glycerate. The fructose-derived glycerate then enters the circulation and reaches the pancreas.

We performed daily glycerate administration to model the high circulating glycerate level among mice. Through metabolic profiling, we found that high circulating glycerate can cause glucose intolerance but not induce insulin resistance. The observed glucose intolerance phenotype is likely related to the reduction in circulating insulin levels and that reduced insulin secretion is independent of the insulin sensitivity among the mice treated with glycerate. In the investigation of the pancreatic islets, we found glycerate treatment promotes pancreatic beta-cell damage and apoptosis.

In conclusion, we demonstrated the interaction between fat and fructose intake, in which high fat intake enhances the fructose metabolism in the small intestine. The up-regulated fructose metabolism in the small intestine enhances the production of glycerate. High circulating glycerate is a risk factor for diabetes development via depletion of insulin content in pancreatic islets. Therefore, this study discovers a novel mechanism for fructose-induced diabetes via the action of glycerate. It also supports the idea of reducing fat and fructose intake simultaneously, rather than either macronutrient alone, to achieve maximal metabolic health benefits.