Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- All Subjects: Nutrition
Description
Objectives Through a cross-sectional observational study, this thesis evaluates the relationship between food insecurity and weight status, eating behaviors, the home food environment, meal planning and preparation, and perceived stress as it relates to predominantly Hispanic/Latino parents in Phoenix, Arizona. The purpose of this study was to address gaps in the literature by examining differences in "healthy" and "unhealthy" eating behaviors, foods available in the home, how time and low energy impact meal preparation, and the level of stress between food security groups. Methods Parents, 18 years or older, were recruited during two pre-scheduled health fairs, from English as a second language classes, or from the Women, Infants, and Children's clinic at a local community center, Golden Gate Community Center, in Phoenix, Arizona. An interview, electronic, or paper survey were offered in either Spanish or English to collect data on the variables described above. In addition to the survey, height and weight were collected for all participants to determine BMI and weight status. One hundred and sixty participants were recruited. Multivariate linear and logistic regression models, adjusting for weight status, education, race/ethnicity, income level, and years residing in the U.S., were used to assess the relationship between food security status and weight status, eating behaviors, the home food environment, meal planning and preparation, and perceived stress. Results Results concluded that food insecurity was more prevalent among parents reporting lower income levels compared to higher income levels (p=0.017). In adjusted models, higher perceived cost of fruits (p=0.004) and higher perceived level of stress (p=0.001) were associated with food insecurity. Given that the sample population was predominately women, a post-hoc analysis was completed on women only. In addition to the two significant results noted in the adjusted analyses, the women-only analysis revealed that food insecure mothers reported lower amounts of vegetables served with meals (p=0.019) and higher use of fast-food when tired or running late (p=0.043), compared to food secure mothers. Conclusion Additional studies are needed to further assess differences in stress levels between food insecure parents and food insecure parents, with special consideration for directionality and its relationship to weight status.
ContributorsVillanova, Christina (Author) / Bruening, Meg (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2014
Description
The omega-3 fatty acids in fatty fish and fish oil, eicosapentanoic acid (EPA) and docosahexanoic acid (DHA), have been associated with a reduction in risk for cardiovascular disease. Blood type is a known contributor to risk for cardiovascular events. This study evaluated the effect of fish oil supplements on cardiovascular risk markers in adults with blood types A or O. An 8-week parallel-arm, randomized, double-blind trial was conducted in healthy adult men and women with either blood type A (BTA) or blood type O (BTO). Participants were randomized to receive fish oil supplements (n=10 [3 BTA/7 BTO]; 2 g [containing 1.2 g EPA+DHA]/d) or a coconut oil supplement (n=7 [3 BTA/4 BTO]; 2 g/d). Markers that were examined included total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), high-sensitivity C-reactive protein (hsCRP), and hemoglobin A1C (HbA1C). Results indicated that the percent change in LDL cholesterol was significantly greater in the coconut oil group vs the fish oil group (-14.8±12.2% vs +2.8±18.9% respectively, p=0.048). There were no other significant differences between treatment groups, or between blood types A and O, for the other cardiovascular risk markers. Further research with a larger and more diverse sample may yield a more conclusive result.
ContributorsHerring, Dana (Author) / Johnston, Carol (Thesis advisor) / Vega-Lopez, Sonia (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2014
Description
In adults, consuming a high-fat meal can induce endothelial dysfunction while exercise may mitigate postprandial endothelial dysfunction. Whether exercise is protective against postprandial endothelial dysfunction in obese youth is unknown. The purpose of this study was to determine if high-intensity interval exercise (HIIE) performed the evening prior to a high-fat meal protects against postprandial endothelial dysfunction in obese adolescent males. Fourteen obese adolescent males (BMI%tile=98.5±0.6; 14.3±1.0yrs) completed the study. After initial screening, participants arrived, fasted at 9:00 in the morning where brachial artery flow-mediated dilation (FMD) was measured using duplex ultrasound after 20min of supine rest (7.0±3.0%) and completed a maximal exercise test on a cycle ergometer (VO2peak=2.6±0.5 L/min). Participants were randomized and completed 2 conditions: a morning high-fat meal challenge with evening prior HIIE (EX+M) or a morning high-fat meal challenge without prior exercise (MO). The EX+M condition included a single HIIE session on a cycle ergometer (8 X 2min at ≥90%HRmax, with 2min active recovery between bouts, 42min total) which was performed at 17:00 the evening prior to the meal challenge. In both conditions, a mixed-meal was tailored to participants body weight consisting of 0.7g of fat/kg of body weight consumed (889±95kcal; 65% Fat, 30% CHO). FMD was measured at fasting (>10hrs) and subsequently measured at 2hr and 4hr after high-fat meal consumption. Exercise did not improve fasting FMD (7.5±3.0 vs. 7.4±2.8%, P=0.927; EX+M and MO, respectively). Despite consuming a high-fat meal, FMD was not reduced at 2hr (8.4±3.4 vs. 7.6±3.9%; EX+M and MO, respectively) or 4hr (8.8±3.9 vs. 8.6±4.0%; EX+M and MO, respectively) in either condition and no differences were observed between condition (p(condition*time)=0.928). These observations remained after adjusting for baseline artery diameter and shear rate. We observed that HIIE, the evening prior, had no effect on fasting or postprandial endothelial function when compared with a meal only condition. Future research should examine whether exercise training may be able to improve postprandial endothelial function rather than a single acute bout in obese youth.
ContributorsRyder, Justin Ross (Author) / Shaibi, Gabriel Q (Thesis advisor) / Gaesser, Glenn A (Committee member) / Vega-Lopez, Sonia (Committee member) / Crespo, Noe C (Committee member) / Katsanos, Christos (Committee member) / Arizona State University (Publisher)
Created2014
Description
Studies have demonstrated that anthocyanins can function as antioxidants, reduce inflammation, and improve dyslipidemia. Tart cherries are anthocyanin-rich, making them particularly attractive as a functional food to improve cardiovascular disease (CVD) risk. There have been few published studies to date examining the impact of tart cherries on biomarkers of dyslipidemia and inflammation, particularly in overweight and obese individuals at high risk for these conditions. This study evaluated the effect of consuming 100% tart cherry juice daily on blood lipids including total cholesterol, low-density lipoprotein cholesterol (LDL-C), calculated very low density lipoprotein cholesterol (VLDL-C), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), and the CVD risk ratios, as well as the inflammatory biomarkers interleukin 6 (IL-6), interleukin 10 (IL-10), tumor necrosis factor-alpha (TNF-alpha), C-reactive protein (CRP), monocyte chemotactic protein-1 (MCP-1), and erythrocyte sedimentation rate (ESR) following a 4-week period. Based on the high anthocyanin content of tart cherries, it was hypothesized that the lipid and inflammatory profiles would be significantly improved following the intervention. A total of 26 men and women completed this 4-week randomized, single-blind, placebo-controlled, crossover study. Participants were randomized to drink either 8 ounces of placebo beverage or tart cherry juice daily for 4 weeks. Following a 4-week washout period, the alternate beverage was consumed. Ultimately, this investigation demonstrated no statistically significant alterations in any of the lipid or inflammatory biomarkers when analyzed across time and between interventions (p > 0.05). As expected, glucose and insulin parameters remained stable over the duration of the study, as well as self-reported physical activity level, total calorie consumption, and macronutrient intake. However, trans-fat was reported to be significantly higher during the cherry arm of the study as compared to the placebo arm (p < 0.05), potentially confounding other results. Although the results of this study were equivocal, it is feasible that a higher dose, longer treatment duration, or more susceptible target population may be required to elicit significant effects. Consequently, further investigation is necessary to clarify this research.
ContributorsColes, Katie (Author) / Martin, Keith R. (Thesis advisor) / Traustadottir, Tinna (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2012
Description
Despite recent strides for awareness, treatment, and control of hypertension, prevalence remains high with estimates suggesting one third of Americans have hypertension. The hypotensive effects of potassium and magnesium have been known and administered in a clinical setting for nearly a century. The purpose of this study was to examine the effectiveness of taking a potassium/magnesium supplement to help reduce blood pressure in individuals with mildly-moderately elevated blood pressure. In this randomized, controlled crossover trial, potassium and magnesium supplementation was explored among healthy adults with mildly elevated blood pressure in Phoenix, Arizona. Subjects (n = 12) were randomly assigned to ingest either the treatment chewy bar (217 mg potassium/day; 70.8 mg magnesium/day) or a placebo chewy bar for four weeks. For the subsequent four weeks, subjects ingested the other corresponding chewy bar. Systolic (SBP), diastolic (DBP), and average blood pressure values were not significantly different between the two groups (p = 0.645, p = 0.464 and p = 0.939, respectively). Baseline mean blood pressure was 121.0/75.7 mm Hg. The 12 subjects (8 females, 4 males) had a mean age of 29.3 years old and a mean BMI of 26.2. After four weeks, the treatment group had a slightly higher SBP (118.3 ± 13.3 mm Hg) than the control group (116.5 ± 17.8 mm Hg); however, DBP was lower in the treatment group (71.7 ± 12.4 mm Hg) than the control group (73.0 ± 10.0 mm Hg). In conclusion, daily supplementation of potassium and magnesium (217.2 mg/day and 70.8 mg/day, respectively) did not significantly lower blood pressure in adults with mildly-moderately elevated blood pressure.
ContributorsPawloski, Jason (Author) / Johnston, Carol (Thesis advisor) / Vega-Lopez, Sonia (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2015
Description
Although past literature has examined the prevalence of campus food pantries, most have not examined student satisfaction of campus food pantries the acceptability and feasibility of the campus food pantries in the U.S. This descriptive and quasi-experimental study assessed the acceptability and feasibility of campus food pantry intervention on two campuses (Downtown Phoenix and Tempe) at Arizona State University (ASU). The acceptability measures were composed of 30 survey questions including demographics, satisfaction survey, and food insecurity questionnaires, which were abstracted from the U.S. Adult 10-Item Food Security Survey Module. The food pantry was open once a week at each site. Any ASU students who enrolled in Spring 2017 and visited a food pantry were eligible to participate in the study. A total of 39 ASU students participated in the study during January 2017 and February 2017 (48.1 % female, 42.3 % White). The number of surveys collected at each site was 52. The majority of students were first-year undergraduate students (57.9% Downtown Phoenix, 45.5% Tempe). Based on their answers to the U.S. Adult 10-Item Food Security Survey Module, 21.2% of students (n=11) indicated low food security, while 48.1% of students (n=25) indicated very low food security. Almost 70% of pantry users reported that they have experienced food insecurity. In this study, the majority (90%) of students were satisfied with the service, hours of operation, and location for both the Downtown and Tempe food pantries. Additionally, 85.7% of students reported that they need additional resources such as financial aid (49%), a career center (18.4%), health services (10.2%), and other services (8.2%). The Pitchfork Pantry operated by student, university, and community support. Total donations received between Fall 2016 and Spring 2017 were 4,600 food items. The study found that most students were highly satisfied with the campus food pantries and it was feasible to operate two pantries on the ASU campus. These findings can be used to contribute to future research into campus food pantries, which may be the solution for food insecurity intervention among college populations.
ContributorsKim, Ellie (Author) / Bruening, Meg (Thesis advisor) / Ransdell, Lynda (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2018
Description
BACKGROUND: The purpose of this study was to gain a better understanding of what food insecurity among college students. Qualitative research regarding food insecurity on college campuses has been growing as we gain a better understanding of how prevalent this issue is and its broad impact on students. However, to our knowledge there are only a handful of studies that examined the student and university staff experience using mixed methods. Qualitative data is needed to gain a deeper understanding of the student experience. OBJECTIVE: To gain deeper insights about students’ food insecurity experiences from students themselves and the university staff members who work with them. This insight is necessary to shift university’s current policies and approach to helping students experiencing food insecurity and removing the stigma of the “starving student” experience. METHODS: Surveys and interviews were used to collect data from students to gain an understanding of their current living situations and understand their personal experiences accessing food. University staff completed surveys focused on understanding staff’s experiences with student food insecurity as well as their attitudes and beliefs about students who experience hunger. RESULTS: The current study found that the financial burden of attending college along with student’s food literacy level can contribute to student’s food insecurity. Students identified barriers to food access, discussed their perceptions of their food experience, and also discussed who they lean on for support when struggling with food. Student’s previous life experiences, food literacy, and social support systems all impact the student food experience. University staff identified similar barriers that they perceive students experience when struggling with hunger and also indicated that they have received little to no training or instruction on how to support students experiencing food insecurity. CONCLUSION: These findings can be used as a building block for developing interventions and the implementation of new resources to help minimize food insecurity on college campuses.
ContributorsBrown, Erika (Author) / Bruening, Meg (Thesis advisor) / Vega-Lopez, Sonia (Committee member) / Eakin, Hallie (Committee member) / Arizona State University (Publisher)
Created2018
Description
Background In the United States (US), first-year university students typically live on campus and purchase a meal plan. In general, meal plans allow the student a set number of meals per week or semester, or unlimited meals. Understanding how students’ use their meal plan, and barriers and facilitators to meal plan use, may help decrease nutrition-related issues.
Methods First-year students’ meal plan and residence information was provided by a large, public, southwestern university for the 2015-2016 academic year. A subset of students (n=619) self-reported their food security status. Logistic generalized estimating equations (GEEs) were used to determine if meal plan purchase and use were associated with food insecurity. Linear GEEs were used to examine several potential reasons for lower meal plan use. Logistic and Linear GEEs were used to determine similarities in meal plan purchase and use for a total of 599 roommate pairs (n=1186 students), and 557 floormates.
Results Students did not use all of the meals available to them; 7% of students did not use their meal plan for an entire month. After controlling for socioeconomic factors, compared to students on unlimited meal plans, students on the cheapest meal plan were more likely to report food insecurity (OR=2.2, 95% CI=1.2, 4.1). In Fall, 26% of students on unlimited meal plans reported food insecurity. Students on the 180 meals/semester meal plan who used fewer meals were more likely to report food insecurity (OR=0.9, 95% CI=0.8, 1.0); after gender stratification this was only evident for males. Students’ meal plan use was lower if the student worked a job (β=-1.3, 95% CI=-2.3, -0.3) and higher when their roommate used their meal plan frequently (β=0.09, 99% CI=0.04, 0.14). Roommates on the same meal plan (OR=1.56, 99% CI=1.28, 1.89) were more likely to use their meals together.
Discussion This study suggests that determining why students are not using their meal plan may be key to minimizing the prevalence of food insecurity on college campuses, and that strategic roommate assignments may result in students’ using their meal plan more frequently. Students’ meal plan information provides objective insights into students’ university transition.
Methods First-year students’ meal plan and residence information was provided by a large, public, southwestern university for the 2015-2016 academic year. A subset of students (n=619) self-reported their food security status. Logistic generalized estimating equations (GEEs) were used to determine if meal plan purchase and use were associated with food insecurity. Linear GEEs were used to examine several potential reasons for lower meal plan use. Logistic and Linear GEEs were used to determine similarities in meal plan purchase and use for a total of 599 roommate pairs (n=1186 students), and 557 floormates.
Results Students did not use all of the meals available to them; 7% of students did not use their meal plan for an entire month. After controlling for socioeconomic factors, compared to students on unlimited meal plans, students on the cheapest meal plan were more likely to report food insecurity (OR=2.2, 95% CI=1.2, 4.1). In Fall, 26% of students on unlimited meal plans reported food insecurity. Students on the 180 meals/semester meal plan who used fewer meals were more likely to report food insecurity (OR=0.9, 95% CI=0.8, 1.0); after gender stratification this was only evident for males. Students’ meal plan use was lower if the student worked a job (β=-1.3, 95% CI=-2.3, -0.3) and higher when their roommate used their meal plan frequently (β=0.09, 99% CI=0.04, 0.14). Roommates on the same meal plan (OR=1.56, 99% CI=1.28, 1.89) were more likely to use their meals together.
Discussion This study suggests that determining why students are not using their meal plan may be key to minimizing the prevalence of food insecurity on college campuses, and that strategic roommate assignments may result in students’ using their meal plan more frequently. Students’ meal plan information provides objective insights into students’ university transition.
Contributorsvan Woerden, Irene (Author) / Bruening, Meg (Thesis advisor) / Hruschka, Daniel (Committee member) / Schaefer, David (Committee member) / Vega-Lopez, Sonia (Committee member) / Adams, Marc (Committee member) / Arizona State University (Publisher)
Created2019
Description
Background: Despite the reported improvements in glucose regulation associated with flaxseeds (Linum usitatissimum) few clinical trials have been conducted in diabetic participants. Objective: To evaluate the efficacy of ground flaxseed consumption at attenuating hyperglycemia, dyslipidemia, inflammation, and oxidative stress as compared to a control in adults with non-insulin dependent type 2 diabetes (T2D). Design: In a randomized parallel arm controlled efficacy trial, participants were asked to consume either 28 g/d ground flaxseed or the fiber-matched control (9 g/d ground psyllium husk) for 8 weeks. The study included 17 adults (9 male, 8 females; 46±14 y; BMI: 31.4±5.7 kg/m2) with a diagnosis of T2D ≥ 6 months. Main outcomes measured included: glycemic control (HbA1c, fasting plasma glucose, fasting serum insulin, and HOMA-IR), lipid profile (total cholesterol, LDL-C, HDL-C, total triglycerides, and calculated VLDL-C), markers of inflammation and oxidative stress (TNF-alpha, TBARS, and NOx), and dietary intake (energy, total fat, total fiber, sodium). Absolute net change for measured variables (week 8 values minus baseline values) were compared using Mann-Whitney U non-parametric tests, significance was determined at p ≤ 0.05. Results: There were no significant changes between groups from baseline to week 8 in any outcome measure of nutrient intake, body composition, glucose control, or lipid concentrations. There was a modest decrease in TNF-alpha in the flaxseed group as compared to the control (p = 0.06) as well as a mild decrease in TBARS in the flaxseed as compared to the control group (p = 0.083), though neither were significant. Conclusions: The current study did not detect a measurable association between 28 g/d flaxseed consumption for 8 weeks in T2D participants and improvements in glycemic control or lipid profiles. There was a modest, albeit insignificant, decrease in markers of inflammation and oxidative stress in the flaxseed group as compared to the control, which warrants further study.
ContributorsRicklefs, Kristin (Author) / Sweazea, Karen L (Thesis advisor) / Johnston, Carol S (Committee member) / Gaesser, Glenn (Committee member) / Vega-Lopez, Sonia (Committee member) / Gonzales, Rayna (Committee member) / Arizona State University (Publisher)
Created2015
Description
Latino youth are disproportionately impacted by obesity, prediabetes and type 2 diabetes (T2D). Pediatric obesity is characterized by abnormal increases in pro-inflammatory markers, including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and monocyte chemoattractant protein-1 (MCP-1) and reductions in anti-inflammatory markers, high molecular weight adiponectin (HMW Adpn) and interleukin-10 (IL-10). Interleukin-1 receptor antagonist (IL-1ra) is an anti-inflammatory that is positively associated with obesity. IL-6, TNF-α, MCP-1 and IL-1ra have been associated with reduced insulin sensitivity and β-cell dysfunction, two central pathophysiologic mediators of glucose intolerance, while HMW Adpn and IL-10 have been associated with increased insulin sensitivity and β-cell function. The United States Diabetes Prevention Program (DPP) supported lifestyle intervention as the cornerstone approach for preventing T2D among adults with prediabetes, yet no studies to date have assessed the efficacy of an adapted DPP among Latino youth with prediabetes. In this dissertation, three studies were conducted. The first cross-sectional study among Latino youth with prediabetes and obesity (n=65) demonstrated that MCP-1 (β=-0.001, p=0.027; β=0.03, p=0.033), HMW Adpn (β=0.2, p<0.001; β=-2.2, p=0.018), and IL-1ra (β=-0.03, p=0.006; β=0.09, p=0.009) significantly predicted insulin sensitivity (measured by whole body insulin sensitivity index, WBISI) and glucose tolerance (measured by 2-hr glucose concentrations from an oral glucose tolerance test), respectively. Only HMW Adpn significantly predicted β-cell function, measured by oral disposition index, or oDI (β=0.6, p<0.001). The second study was a randomized control trial that demonstrated the efficacy of lifestyle intervention (INT, n=79) for improving oDI among Latino youth with prediabetes and obesity, compared to a usual care control (UCC, n=38) group. No differences were found for changes in WBISI (Δ0.1, p=0.899) or 2-hr glucose (Δ-7.2, p=0.260) between groups. The third study was a secondary analysis (INT n=46, UCC n=29) that demonstrated no significant effects on IL-6, TNF-α, MCP-1, HMW Adpn, IL-10, or IL-1ra (all interactions, p>0.05).
ContributorsPena, Armando (Author) / Shaibi, Gabriel Q. (Thesis advisor) / Vega-Lopez, Sonia (Committee member) / Sears, Dorothy D (Committee member) / Ayers, Stephanie L (Committee member) / Olson, Micah L (Committee member) / Arizona State University (Publisher)
Created2022