Ph.D. - Nutritional Sciences
Permanent URI for this collectionhttps://hdl.handle.net/10125/73299
Browse
Recent Submissions
Item type: Item , A comprehensive approach to breast cancer early detection in Pacific communities with high rates of obesity(University of Hawai'i at Manoa, 2025) Valdez, Dustin; Shepherd, John A.; Nutritional SciencesBreast cancer mortality remains disproportionately high among women in the Pacific region, driven by elevated rates of advanced-stage diagnosis, widespread obesity, complex ethnic mixture, and limited healthcare resources. This dissertation aimed to address these disparities by examining the interplay of obesity, ethnic mixture, and access to effective screening technologies in influencing breast cancer outcomes among Pacific Islander populations. In Study 1, clinical and demographic data from the Hawaii and Pacific Islands Mammography Registry (HIPIMR) were utilized to create a regional disparity index to classify risk profiles for each region and multivariable Cox proportional hazard models were used to identify significant geographic variations for overall breast cancer and advanced breast cancer. Based on the regional disparity index, we identified that women from Kauai or outside of Hawaii, and White women had higher risk profiles due to elevated proportions of high breast density. Women from Honolulu County had the lowest risk profile mainly due to being fairly lean, and being predominantly Asian. Cox models revealed that women from Kauai (HR=2.81; CI:1.15-6.81) and Maui (HR=3.15; CI:1.80-5.02) had significantly higher overall breast cancer risk compared to women from other regions in Hawaii. However, no significant associations were found between these regions for women with advanced breast cancer. Study 2 leveraged data from the Multiethnic Cohort (MEC) to investigate how ethnic mixture interacts with body mass index (BMI) to influence breast cancer incidence among Native Hawaiian (NH) women. Although age-adjusted incidence rates were highest among NH-only and NH/White/Chinese women (5.7 and 5.9 per 1,000 person-years, respectively) and lowest among NH/Other (3.6 per 1,000 person-years) women, these differences did not translate into statistically significant hazard ratios (HRs) in Cox models. Study 3 validated the clinical efficacy and acceptability of a novel, portable breast cancer screening device, the iBreastExam (iBE), among women in Guam, a representative Pacific setting with low-resources. Clinical validation, phantom studies, and patient surveys confirmed iBE’s utility as an acceptable device but had low clinical sensitivity (60%). Collectively, these studies inform and refine the Makawalu Paradigm, a culturally responsive and sustainable early detection framework specifically developed for Pacific Island populations.Item type: Item , Bringing nutrition home: An exploration of home-based cooking kit interventions for children and families(University of Hawai'i at Manoa, 2025) Kwan, Cherese; Esquivel, Monica K.; Nutritional SciencesAdequate fruit and vegetable (FV) consumption is essential for chronic disease prevention, yet many U.S. children, particularly those residing in low-income and food-insecure households, fall short of recommended levels. This research explored the use of home-based cooking kits as an innovative strategy for improving FV intake. The dissertation comprises 3 manuscripts. Manuscript 1 is a scoping review of home-based cooking kit interventions for households with children. Of the 24 publications included, there was a wide range of study characteristics, participant characteristics, and outcomes. The review identified a need for more research on intervention development details, stakeholder perspectives, and long-term sustainability. A systematic review of the literature with broadened inclusion criteria is warranted. Manuscript 2 quantitatively evaluated the Food Activity Bag (FAB) intervention, a novel home-based cooking kit, integrated within a Produce Prescription program for pediatric patients (2 – 17 years old) at a Federally Qualified Health Center in Hawai’i. Pre- and post-intervention surveys with children showed no statistically significant changes between intervention and comparison groups. However, the intervention group exhibited near-significant improvements in food and nutrition knowledge (p=0.08), willingness to try vegetables (p=0.07), WTT FV targeted in the intervention (p=0.07), and WTT some of the targeted FV. The small sample size may have limited statistical power, necessitating larger-scale studies. Manuscript 3 qualitatively explored the FAB intervention through semi-structured interviews with intervention participants (parents and children), revealing 5 key themes on feasibility, acceptability, and preliminary impact of the FAB intervention. Overall, the FAB was well-accepted and demonstrates potential as an appropriate intervention for the predominantly Native Hawaiian and Pacific Islander population. The Coronavirus 2019 pandemic introduced considerable challenges throughout the research process. Future research conducted under more stable conditions may be able to obtain a larger sample size and more effectively evaluate the intervention’s impact. Collectively, this dissertation suggests home-based cooking interventions, such as the FAB, hold promise for improving FV intake, among other health outcomes. Future studies on cooking kits should report detailed development processes, explore broader stakeholder perspectives, and identify ways to support long-term sustainability.Item type: Item , ANTIMICROBIAL, ANTIVIRULENCE, AND ANTIBIOTIC POTENTIATION PROPERTIES OF OHELO BERRY (VACCINIUM CALYCINUM) AGAINST SALMONELLA TYPHIMURIUM(University of Hawai'i at Manoa, 2023) Wu, Biyu; Li, Yong; Nutritional SciencesFood contamination caused by pathogenic bacteria remains a significant concern in ensuring food safety. Salmonella is an important foodborne pathogen that can cause gastroenteritis in both humans and animals, posing a substantial threat to life and health. Such contamination leads to declining quantity and quality of food products and may adversely affect consumer health. The emergence and dissemination of antibiotic-resistant bacteria, fueled by the excessive and inappropriate use of antibiotics, further complicates the issue. Consequently, there is an increasing demand for the development of novel and natural antimicrobial agents, especially as the risks posed by drug-resistant bacteria seriously endanger human health. Ohelo berry (Vaccinium calycinum), an endemic and culturally significant fruit in Hawaii, is characterized by its high content of phenolic compounds. These compounds have demonstrated potent antimicrobial properties against pathogenic bacteria. This dissertation aims (1) to evaluate the antimicrobial activity and modes of action of ohelo berry against Salmonella Typhimurium; (2) to investigate the antivirulence effects of ohelo berry against S. Typhimurium; and (3) to explore the antibiotic potentiation property of ohelo berry against multi-drug resistant S. Typhimurium. In the first part, fresh ohelo berry fruits were collected from the island of Hawaii, and their bioactive compounds were extracted using an organic solvent (F0). These compounds were further separated into sugars plus organic acids (F1), monomeric phenolics (F2), anthocyanins (F3), and proanthocyanidins (F4). The minimum inhibitory concentrations (MIC) of ohelo berry F0, F1, F2, F3, and F4 against S. Typhimurium were determined as 3.125%, 12.5%, 25%, 50%, and 25%, respectively. Ohelo berry F0 significantly inhibited the physicochemical properties and biofilm formation of S. Typhimurium. The antimicrobial mode of action experiments revealed that F0 could disrupt cell membrane integrity, alter membrane potential, cause protein leakage, and interact with bacterial genomic DNA. Furthermore, all fractions induced significant damage to S. Typhimurium in varying degrees, with motility being inhibited by F1 and F4, and biofilm formation being primarily inhibited by F1. The decrease in hydrophobicity and auto-aggregation was mainly attributed to F2 and F4, respectively. Additionally, the fractions exhibited different bactericidal effects on S. Typhimurium, with membrane damage, protein leakage, membrane depolarization, and DNA binding being primarily attributed to F3, F4, F2, and F1, respectively. The findings from this part increased our understanding of S. Typhimurium’s susceptibility to ohelo berry constituents, providing a theoretical basis for applying ohelo berry in controlling S. Typhimurium infections. The second part of this dissertation evaluated the pathogenicity and virulence gene expression of S. Typhimurium in the presence of sublethal concentrations of ohelo berry constituents. The sub-inhibitory concentrations of ohelo berry constituents showed no effects on the viability of human intestinal epithelial Caco-2 cells. The effects of ohelo berry constituents on bacterial adhesion and invasion and inflammatory response following S. Typhimurium infections under three scenarios: pre-incubation of ohelo berry with Caco-2 cells, pre-incubation of ohelo berry with bacteria, and co-incubation of ohelo berry with Caco-2 cells and bacteria. These three scenarios were applied to replicate possible conditions of bacterial infection. Results showed that the number of the adhered S. Typhimurium was significantly reduced by pre-incubation of bacteria with ohelo berry F0, F1, and F2. The invaded bacteria were significantly decreased by ohelo berry constituents to different degrees. The production of pro-inflammatory interleukin-8 by S. Typhimurium infected Caco-2 cells was significantly reduced in the presence of ohelo berry. Furthermore, viable bacterial counts were reduced to below the limit of detection (< 1 log CFU/mL) after the gastric phase in the presence of F0, and this reduction persisted through the intestinal phase. Ohelo berry F1 reduced viable bacterial counts to an undetectable level after gastric and intestinal phases (< 1 log CFU/mL). Ohelo berry F2 and F4 caused a significant reduction in viable bacterial counts (2 log CFU/mL) compared to the control after the intestinal phase. The relative expression of virulence genes (hilA/C/D, invA/E/H, and prgH/K) was significantly downregulated in the presence of sublethal concentrations of F0, F2, and F4. These findings demonstrated the potential of ohelo berry in exerting protective effects against Salmonella infection, suggesting gut health benefits. In the last part, the interactions of ohelo berry with antibiotics against multi-drug resistant S. Typhimurium DT104 were investigated. The checkerboard microdilution assay was performed and showed that ohelo berry F4 (proanthocyanidins) exhibited the most potent synergistic effects with chloramphenicol and tetracycline, reducing MICs of antibiotics by 4- to 8-fold. Ohelo berry proanthocyanidins were able to restore the susceptibility of S. Typhimurium DT104 to antibiotics by preventing the evolution of resistance, suppressing the reactivation of antibiotic-exposed bacteria, disrupting membrane integrity, and inhibiting biofilm formation. The observed antibiotic potentiation properties of ohelo berry proanthocyanidins were due to increased outer and inner membrane permeability and inhibition of efflux pump activity. Overall, this research provided a foundation for novel therapy development using ohelo berry bioactive compounds in combination with currently available antibiotics against multi-drug resistant bacterial infections. This study was the first to explore the impacts of ohelo berry on pathogenic bacteria. The findings increase our understanding of the antimicrobial, antivirulence, and antibiotic potentiation properties of ohelo berry against S. Typhimurium. Future research endeavors, including food product development, pharmacological analysis, clinical trials, and ecological impact assessments, are essential to fully elucidate the multifaceted role of ohelo berries. Such comprehensive studies hold the promise of enhancing our knowledge of the potential contributions of ohelo berries, particularly in the areas of nutrition, health, cultural significance, and conservation.Item type: Item , The role of poi as a naturally fermented Hawaiian food in the modulation of gut health(University of Hawaii at Manoa, 2023) Dong, Lianger; Li, Yong; Nutritional SciencesPoi, a culturally significant staple food in the Hawaiian diet, is traditionally made from cooked taro and can undergo natural fermentation by lactic acid bacteria (LAB). Previous studies have suggested potential health benefits of poi, such as its prebiotic, probiotic, and anti-cancer properties. However, the specific health advantages and the underlying mechanisms related to the probiotic nature of poi remain unclear. The gut microbiota plays crucial roles in various physiological functions, and communication within this microbial community is facilitated by the production of metabolites such as short-chain fatty acids (SCFAs). Probiotics and probiotic foods can help replenish beneficial bacteria in the gut and reduce chronic inflammation in the intestines associated with gastrointestinal disorders. Poi, as a naturally fermented food, has the potential to deliver beneficial bacteria and improve gut homeostasis. This dissertation aimed to investigate the probiotic properties of poi, its anti-inflammatory effects, its regulation of lipid metabolism, and its impact on gut microbiota.Six commercially available poi brands were subjected to simulated gastrointestinal digestion, and LAB surviving the process were isolated and identified. The analysis revealed changes in bacterial abundance and diversity in poi after digestion, identifying 13 different LAB species, including the most prevalent species: Leuconostoc lactis, Leuconostoc mesenteroides, Enterococcus lactis, Leuconostoc pseudomesenteroides, and Lactiplantibacillus plantarum. Some LAB isolates demonstrated antimicrobial activities against Listeria monocytogenes and/or Salmonella enterica serotype Typhimurium, as well as bile salt hydrolase activities and cholesterol assimilation. The adhesion abilities to human intestinal epithelial cells (Caco-2) varied among the LAB isolates. Furthermore, extracts from both fresh and fermented poi were tested on Caco-2 cells to evaluate their effects on bacterial infection, inflammation, oxidative stress, and lipid metabolism. The extracts inhibited the adhesion and invasion of L. monocytogenes and S. Typhimurium, suppressed the expression of pro-inflammatory genes, promoted the expression of anti-inflammatory genes, and upregulated tight junction proteins essential for gut barrier integrity. The poi extracts also influenced gene expressions related to lipid metabolism, favoring lipid oxidation and gastrointestinal immunoregulation, including PPARs, FIAF, and SREBP-2. Finally, the impact of fresh and fermented poi on human gut microbiota was assessed using in vitro fecal fermentations. Fermented poi significantly increased microbial diversity. Both fresh and fermented poi altered microbial community structure and promoted the production of SCFAs, including butyrate, valerate, isobutyrate, and isovalerate. Poi affected the abundances of various bacterial phyla and genera, increasing beneficial genera such as Bacteroides, Bifidobacterium, and Roseburia, while decreasing potentially harmful genera such as Fusobacterium and Klebsiella. The fermented poi group exhibited more pronounced effects on gut microbiota and predicted metabolic pathways compared to the fresh poi group. In conclusion, this study has illuminated the potential probiotic properties of poi, especially fermented poi, as demonstrated by the presence of probiotic LAB, inhibition of pathogenic bacteria, modulation of inflammatory responses, enhancement of gut barrier function, and influence on gut microbiota composition and SCFA production. Further research is needed to elucidate the contribution of specific bioactive compounds in poi to its health-promoting attributes. The findings presented in this dissertation may contribute to the development of preventive strategies against inflammatory bowel diseases and metabolic syndromes.Item type: Item , Environmentally Sensitive Transcription Factors In The Prolactin Cell, Gill And Kidney Of Mozambique Tilapia (Oreochromis mossambicus)(University of Hawaii at Manoa, 2023) Gardi Hewage, Tharindu Malintha; Seale, Andre P.; Nutritional SciencesIn this thesis, I investigated the molecular mechanisms underlying the transduction of two fundamental sensory modalities, osmoreception and thermosensitivity, in fish. The scope and depth of this investigation was facilitated by employing a tractable study model of high physiological relevance in changing environments, the euryhaline Mozambique tilapia, Oreochromis mossambicus. The pituitary hormone prolactin (Prl) plays a fundamental role during acclimation to fresh water (FW) in euryhaline fishes by promoting ion uptake and retention in osmoregulatory epithelia. Consistent with this role, tilapia Prl cells are sensitive to variations in extracellular osmolality, responding by increasing cell volume and intracellular Ca2+ concentration when osmolality falls. I characterized the activation of transcription factor modules (TFM) from Prl cells following osmotic stimulation and found that their responses were also dependent on the acclimation history of the fish. TFM’s such as pituitary transcription factor 1 (Pit1), were strongly activated by hyposmotic stimuli, while others, such as HMG box-containing protein 1 (SORY_PAX3), a known transcriptional repressor, was activated in response to hyperosmotic stimuli, indicating the presence of molecular mechanisms that both enhance and attenuate prl177 and prl188 transcription in response to osmotic stimuli.Following the recent discovery that a rise in temperature also stimulates Prl release, I tested the involvement of osmosensitve TFMs in Prl cells incubated in temperatures ranging from 20 ℃ to 32 ℃ and found that low temperature inhibits the response of Prl cells to hyposmotic media. Interstingly, TFM transcripts that typically increase with a hyposmotic stimulus were generally downregulated with a rise in temperature. Last, gill and kidney are two of the main osmoregulatory tissues in fish, and targets of Prl’s actions during salinity acclimation. I employed a comparative RNA-seq approach to characterize transcriptional responses of branchial and renal gene networks involved in FW- and seawater (SW)- acclimation. Focusing on the Prl signaling pathway, I identified a number of targets co-expressed with the prl receptor (prlr1) transcripts in FW-acclimated tilapia. These included genes encoding downstream signalling proteins and transcription factors such as jakmip, stat5b, mknk2b, junbb, socs2 and cish. By contrast, in SW-acclimated tilapia, genes associated with a pathway leading to the synthesis of myo-inositol, a metabolite that protects against hyperosmotic stress, were highly expressed in the gill, while stanniocalcin, a hypocalcaemic hormone, was activated in the kidney. Together, these findings shed light into the molecular mechanisms underlying the transcriptional regulation of prls by environmental osmotic and thermal stimuli. The discussion of the complex interaction between activators and repressors of transcription in Prl cells is extended to target tissues, where direct responses to environmental stimuli are integrated with hormonal action to optimize acclimation to FW and SW environments.Item type: Item , Assessing food consumption patterns of young children on Guam through the development of a culturally appropriate food frequency questionnaire (FFQ)(University of Hawaii at Manoa, 2023) Laguana, Michelle Blas; Novotny, Rachel; Nutritional SciencesABSTRACT Food frequency questionnaires (FFQ) can assess usual dietary intake, be tailored to the population of interest, are fairly inexpensive to administer, are cost effective, and have low participation burden. To our knowledge, there is no FFQ to assess usual diet of young children in Guam. This dissertation encompasses three manuscripts whose respective objectives were to: 1) understand the food intake of young children living on Guam, 2) create a diet assessment tool that will help monitor diets of young children in Guam, and 3) pilot and test the newly created diet assessment tool. The first manuscript is an analysis of existing data utilizing cross-sectional data collected on children ages 2-8 yrs. who participated in the Children’s Healthy Living Program (CHL) baseline study. Parents/caregivers completed food records of everything their children ate and drank for two randomly assigned days. Results show high intakes of added sugar, non-whole grains, meat, total energy intake, protein, total carbohydrates, total fat, iron, and sodium. CHamoru children had a statistically higher mean (233.35g) carbohydrate intake per day compared to Other PI (218.53g) and Filipino (225.50g) children in the study. Other PI children had a statistically higher mean (2671.76mg) sodium intake per day compared to CHamoru ((2593.54 mg) and Filipino (2463.05mg) children. Higher intake of dietary fat was found among CHamoru children with Overweight and Obesity (OWOB) compared to CHamoru children with Healthy Weight, also reveals an area for dietary improvement. Overall, intakes were low in fruit, vegetables, milk, and calcium compared to MyPlate recommendations and Dietary Reference Intakes, respectively. The second manuscript used the dietary data collected in the first manuscript to help create a food list for developing a Guam Child FFQ. A food list with frequently consumed foods is the first step to creating an FFQ. Data from all CHL Guam children contributed to the development of the FFQ. A semi-quantitative food frequency questionnaire which included culturally appropriate food items was created. For the third manuscript, the objective was to test the Guam Child FFQ created in the second manuscript. There were a total of 82 children participating in completion of FFQ1and a subsample of 59 participating in the reproducibility (test-retest) and 43 participating in the validation study, which compared results from the FFQ with results from 2 days of records obtained from the Pacific Islands Cohort on Cardiometabolic Health (PICCAH) study. The reproducibility of the FFQ was assessed by Pearson’s correlation coefficient which ranged from 0.60 for cholesterol to 0.74 for sodium. The results of the validation study did not demonstrate good validity of the FFQ, with correlations ranging from 0.17 for iron to 0.50 for calcium using nutrient densities. Although these findings indicate that further modifications and testing to the Guam Child FFQ are needed to improve the validity of the FFQ, reliability of the tool was good. A future goal is to further modify and test the FFQ for future studies to capture usual dietary intake of children in Guam and find ways to monitor and improve diet and health in this population.Item type: Item , Emerging Applications In The Measurement Of Body Composition And Their Relationships To Disease Risk(University of Hawaii at Manoa, 2023) bennett, jonathan; Shepherd, John A.; Nutritional SciencesItem type: Item , External influences on complementary feeding practices of caregivers of Native Hawaiian, Other Pacific Islander and/or Filipino infants residing on O‘ahu, Hawai‘i(University of Hawaii at Manoa, 2022) Kai, Jessie Sekiyo Matsuura Puahau; Revilla, Marie K. F.; Nutritional SciencesThe overall goal of this dissertation was to examine the complementary feeding practices and behaviors of caregivers of Native Hawaiian, Other Pacific Islander and Filipino infants residing on the island of Oʻahu. This knowledge is important in addressing childhood health and infant nutrition particularly in the Native Hawaiian, Other Pacific Islander and Filipino populations as they are under-researched and under-represented in the public health literature despite their health disparities. Prior to the “Exploring First Foods of Keiki on Oʻahu, Hawaiʻi” pilot project which collected data from 2018 – 2019, the last publication on complementary feeding pratices in Hawiʻi was published in 1995, in which a large proportion of mothers in Hawai‘i were observed to not meet the timing recommendation for the introduction of complementary foods. In the decades between the 1995 publication and the data collected in 2018 – 2019 for the pilot project, childhood obesity has increased in the Native Hawaiian, Other Pacific Islander and Filipino populations in Hawaiʻi. Thus, the aim of this dissertation was to fill the knowledge gap by investigating the influences shaping the complementary feeding practices of caregivers of these infants. Chapter one provides background on childhood obesity, infant diet and influences on complementary feeding. Chapter two presents findings from a review of the literature on health behavior theories used to explore reasons why caregiver complementary feed the way they choose too. Studies reviewed included nine obersvational epidimiological studies that included cohort and cross-sectional study designs; and three intervention studies. Health behavior theories from the individual (Theory of Planned Behavior, Stages of Change), interpersonal (Social Cognitive Theory, Culture Care Theory) and community (Social Ecological) suggest multiple constructs shape behavior, presenting potentially modifiable behavioral factors that influence complementary feeding decisions. A secondary analysis of data from a community-oriented pilot project was conducted for chapters three and four. Chapter three presents findings from interviews with caregivers of Native Hawaiian, Other Pacific Islander and Filipino infants, exploring the support caregivers perceive from their family, friends and within their community for their complementary feeding practices. This study found caregivers perceive support regardless of their feeding decisions. Chapter four presents findings from the same database to explore the association between caregiver’s cultural identity, the infant’s household membership, and diet quality; this study found no significant relationships among these variables. Results from these three studies suggest caregiver complementary feeding practices and behaviors are influenced by many factors including the caregivers’ social relationships, cultural and physical environments, socio-economic and nutritional status of the caregivers. However, measuring the effects of these is complicated by the inconsistent health messaging caregivers received. This provides an opportunity for future research and health promotion efforts to increase the nutritional health of infants. Prevention is a recommended strategy for addressing adverse health conditions. Improving complementary feeding practices is one strategy to promote the nutrition and well-being of an individual in the first 1000 days of life.Item type: Item , Exploring The Use Of 3D Optical Imaging For Clinically And Non-clinically Applicable Body Composition Assessment(University of Hawaii at Manoa, 2022) Wong, Michael Cen; Shepherd, John A.; Nutritional SciencesIn recent decades, obesity has risen to concerning rates in children and adults. Children with obesity have a higher risk of staying obese in adulthood. Coupled with obesity, comes with increased risk of metabolic diseases, cardiovascular disease, and some cancers. Body mass index (BMI) and waist circumference (WC) are example surrogate measurements to classify individuals with obesity and to describe body shape in clinical assessments and epidemiological studies. However, BMI and WC may not provide adequate body shape information to describe the complexities of the entire body. Recent developments in three-dimensional optical (3DO) surface imaging have brought new opportunities to assess body shape with a low cost, easy-to-use, and accessible technology. The focus of this dissertation was to further develop techniques of quantifying body composition in children/adolescents and adults. In order for 3DO to be accepted as a viable and reliable body composition modality, accuracy and precision needs to be comparable to the current reference methods. Therefore, the aims of the dissertation are as follows: 1) Determine if automated anthropometry from 3DO can predict accurate and precise body composition in children and adolescents; 2) Identify optimal 3D mesh qualities and processes that would improve the accuracy and precision of statistical shape models; 3) Determine how the change in body shape is associated and predictive to the change in body composition.Item type: Item , Influence Of Parental Practices On Eating Habits Of Early Adolescents In Hawaiʻi(University of Hawaii at Manoa, 2021) Suzuki, Asuka; Banna, Jinan; Nutritional SciencesDespite the importance of establishing healthy dietary behaviors during adolescence, most of the adolescents in Hawaiʻi do not meet the appropriate dietary recommendations. They tend to have poor fruit and vegetable intake, while overindulging in sugar-sweetened beverages, which may affect their weight and health in the present and later in life. Parental practices are one of the most significant factors that may influence the eating behaviors of early adolescents. This dissertation encompasses three manuscripts whose respective aims were to: 1) examine the psychometric properties of the Comprehensive Feeding Practices Questionnaire (CFPQ) with parents of early adolescents in Hawaiʻi; 2) describe the feeding practices of a diverse group of parents of early adolescents in Hawaiʻi and examine differences in practices according to parental demographic characteristics; and 3) identify key parental practices that influence the eating behaviors of early adolescents during the occasions when they eat alone or without their primary caregivers among low- and middle- to high-income households in Hawaiʻi. The first and the second manuscripts utilized a cross-sectional design with 155 parents of 9- to-14-year-old adolescents in Oʻahu, Hawaiʻi. Recruited parents completed the revised CFPQ. The first manuscript examined factorial structure and internal consistency reliability using principal component analysis and concluded that the Hawaiʻi CFPQ demonstrated acceptable psychometric properties for ethnically diverse parents of 9- to 14-year-old children in Hawaiʻi. The second manuscript calculated a general linear model to assess the association between parental practices and each demographic characteristic using the subscales of the CFPQ that was examined in the first manuscript. The results illustrated that 6 parental practices such as environment were associated with several demographic characteristics. For the third manuscript, early adolescents (n=45) and their parents/caregivers (n=46) were recruited on Oʻahu, Hawaiʻi, and one-on-one interviews were conducted. Participants were classified as low- and middle- to high-income groups based on financial eligibility. Using the Sort and Sift, Think and Shift qualitative data analysis approach, interview data were analyzed and revealed four main themes and several subthemes under each main theme. The same main themes and subthemes emerged from both income groups. The outcomes of this dissertation may inform the development of effective interventions for promoting positive parental practices to establish healthy eating behaviors in adolescents in Hawaiʻi.Item type: Item , The Potential of Taro (Colocasia Esculenta) as a Dietary Prebiotic Source for the Prevention of Colorectal Cancer(University of Hawaii at Manoa, 2020) Saxby, Solange Majewska; Li, Yong; Nutritional SciencesTaro (Colocasia esculenta) is a high dietary fiber tuber that holds great cultural and agricultural importance in the Pacific. Dietary fiber is the portion of food that is indigestible by the human gastrointestinal tract. Some dietary fibers are prebiotics since they can promote the growth of probiotic bacteria in the gut and their production of healthful short-chain fatty acids (SCFA). Maintaining a homeostatic gut microbiota through dietary modifications with the inclusion of high fiber foods has been shown to reduce the risk of colorectal cancer (CRC). CRC development is highly influenced by diet, with high fiber diets showing preventative properties. Thus, consumption of taro could potentially promote healthy gut microbiota and SCFA production and reduce CRC risk.This dissertation aimed to investigate the potential of taro as a prebiotic and explore its preventative characteristics against CRC through biochemical and epidemiological means. Through the biochemical methodology, five taro varieties were analyzed for the following objectives: 1) Determine the nutrient, physicochemical, and functional properties of taro varieties; 2) Determine the prebiotic fiber contents of taro varieties and their prebiotic activity scores after they were digested and absorbed in vitro; and 3) Understand the microbial changes that occur in the gut microbiome due to the presence of taro via in vitro fecal fermentation. Through the epidemiological methodology, the inclusion of taro as a high dietary fiber source was explored for the following objectives: 4) Determine the influence of taro on the risk of CRC through the analysis of the Multi Ethnic Cohort (MEC) Study and 5) Determine the association of dietary patterns, that include taro and taro products in the food groups, with CRC risk, using the MEC data. The outcomes of this dissertation contribute to increased knowledge of the biochemical and epidemiological aspects of taro’s beneficial properties for CRC prevention. Evidence of the nutrient composition and dietary prebiotic properties of taro, and its association with the activity of gut microbiota and the risk of CRC may help formulate effective prevention strategies for CRC.