ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
Displaying 11 - 20 of 38
Description
The purpose of this study was to gather qualitative data on different and novel methods used to self-monitor diet and exercise during a weight loss study. Participants who used either a traditional paper and pencil method or a smart phone weight loss app for diet and exercise tracking were recruited for focus groups. Focus group discussions centered on the liked and disliked aspects of recording, perceived behavior changes, and suggestions for improved self-monitoring. Focus groups were organized based on the method of self-monitoring. The app group tracked calorie intake and expenditure via the "Lose It" app on their smart phones. The paper & pencil group recorded exercise and food intake in a journal and self-regulated diet based on recommended servings from each food group (or exchange lists). Focus group sessions were audio-recorded, transcribed and coded by the researcher and an independent coder. Results indicated that app participants liked the convenience, affordability, and user-friendly features, but wanted more nutrition advice. App participants liked self-managing their diet, not restricting certain foods or food groups and allowing for indulgences by balancing calories and exercise. Also, they desired an accurate estimation of energy expenditure from an app, based on individual characteristics (i.e., gender and age). Participants who recorded on paper liked the size for a visual layout of food entries, but desired a technology-enhanced method with an auto-calculation of calorie intake and expenditure. They also suggested increased accountability and opportunities for social support would enhance self-monitoring. Overall, an ideal technology-assisted self-monitoring app or program would be free and include an auto-calculation of calorie intake, a gender- and age- specific estimation of calories expended, easy entry of foods from a large database, the ability to enter whole recipes, nutrition information and recommendations, and be available via phone, tablet or computer (based on personal preference).
ContributorsSterner, Danielle (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Johnston, Carol (Committee member) / Hall, Richard (Committee member) / Arizona State University (Publisher)
Created2012
Description
Birds have plasma glucose levels that are 1.5-2 times greater than mammals of similar body mass in addition to higher free fatty acid concentrations, both of which would typically impair endothelium-dependent vasodilation if observed in mammals. Endothelium-dependent vasodilation can be stimulated in mammals through the use of acetylcholine (ACh), which primarily acts through nitric oxide (NO) and cyclooxygenase (COX)-mediated pathways, with varying reliance on endothelial-derived hyperpolarizing factors (EDHFs). Very few studies have been conducted on small resistance systemic arteries from birds. The hypothesis was that because birds have naturally high glucose and free fatty acid concentrations, ACh-induced vasodilation of isolated arteries from mourning doves (Zenaida macroura) would be independent of endothelial-derived factors and resistant to high glucose-mediated vascular dysfunction. Small resistance mesenteric and cranial tibial (c. tibial) arteries were pre-constricted to 50% of resting inner diameter with phenyleprine then exposed to increasing doses of ACh (10-9 to 10-5 μM) or the NO donor, sodium nitroprusside (SNP; 10-12 to 10-3 μM). For both vessel beds, ACh-induced vasodilation occurred mainly through the activation of potassium channels, whereas vasodilation of mesenteric arteries additionally occurred through COX. Although arteries from both vessel beds fully dilated with exposure to sodium nitroprusside, ACh-mediated vasodilation was independent of NO. To examine the effect of high glucose on endothelium-dependent vasodilation, ACh dose response curves were conducted following exposure of isolated c. tibial arteries to either a control solution (20mM glucose) or high glucose (30mM). ACh-induced vasodilation was significantly impaired (p = 0.013) when exposed to high glucose, but normalized in subsequent vessels with pre-exposure to the superoxide dismutase mimetic tiron (10 mM). Superoxide concentrations were likewise significantly increased (p = 0.0072) following exposure to high glucose. These findings indicate that dove arteries do not appear to have endogenous mechanisms to counteract the deleterious effects of oxidative stress. Additional studies are required to assess whether endogenous mechanisms exist to protect avian vascular reactivity from systemic hyperglycemia.
ContributorsJarrett, Catherine Lee (Author) / Sweazea, Karen L (Thesis advisor) / Johnston, Carol (Committee member) / Gaesser, Glenn (Committee member) / Arizona State University (Publisher)
Created2012
Description
The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested by Bartoshuk and colleagues (2004), we infused strips of paper with salt water or sugar water. The bitterness rating of the PTC strip had a significant positive linear relationship with ratings of both the intensity of sweet and salt, but the effect sizes were very low, suggesting that the PTC strip does not give a complete picture of tasting ability. Next we investigated whether various seasonings could mask the bitter taste of vegetables and whether this varied with tasting ability. We found that sugar decreased bitterness and lemon decreased liking for vegetables of varying degrees of bitterness. The results did not differ by ability to taste any of the flavors. Therefore, even though there are remarkable individual differences in taste perception, sugar can be used to improve the initial palatability of vegetables and increase their acceptance and consumption.
ContributorsWilkie, Lynn Melissa (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2012
Description
Background: Twenty-four hour urinary sucrose and fructose (24uSF) has been developed as a dietary biomarker for total sugars intake. Collection of 24-h urine is associated with high costs and heavy participant burden, while collection of spot urine samples can be easily implemented in research protocols. The aim of this thesis is to investigate the utility of uSF biomarker measured in spot urine. Methods: 15 participants age 22 to 49 years completed a 15-day feeding study in which they consumed their usual diet under controlled conditions, and recorded the time each meal was consumed. Two nonconsecutive 24-hour urines, where each urine void was collected in a separate container, were collected. Four timed voids (morning, afternoon, evening, and next day) were identified based on time of void and meal time. Urine samples were measured for sucrose, fructose and creatinine. Variability of uSF excretion was assessed by coefficient of variation (%CV) and variance ratios. Pearson correlation coefficient and multiple linear regression were used to investigate the association between uSF in each timed void and corresponding 24uSF excretion. Results: The two-day mean uSF was 50.6 mg (SD=29.5) for the 24-h urine, and ranged from 4.5 to 7.5 mg/void for the timed voids. The afternoon void uSF had the lowest within-subject variability (49.1%), and lowest within- to between-subject variance ratio (0.2). The morning and afternoon void uSF had the strongest correlation with 24-h uSF for both mg/void (r=0.80 and r=0.72) and mg/creatinine (r=0.72 and r=0.67), respectively. Finally, the afternoon void uSF along with other covariates had the strongest predictive ability of 24-h uSF excretion (mg/void) (Adjusted R2= 0.69; p=0.002), whereas the morning void had the strongest predictive ability of 24-h uSF excretion (mg/g creatinine) (adjusted R2= 0.58; p=0.008). Conclusions: The afternoon void uSF had the most favorable reproducibility estimates, strong correlation with 24uSF excretion, and explained greatest proportion of the variability in 24uSF. USF in mg/void may be better to use than uSF in mg/g creatinine as a biomarker in spot urine. These findings need to be confirmed in a larger study, and in a study population with a wide range of sugars intake.
ContributorsAverill, Annalisa (Author) / Tasevska, Natasha (Thesis advisor) / Shepard, Christina (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2018
Description
Multiple health-related benefits have been associated with adherence to plant-based diets, including vegan, vegetarian, and pescatarian dietary patterns. Despite a consistent body of evidence on the importance of healthy diets, Americans continue to find difficulty in establishing and adhering to dietary goals that could elicit long-term health benefits. Recent research suggests an important role for goal-setting strategies in health behavior change attempts, with some success shown in dietary behavior change, specifically. The current study thus aimed to explore whether having multiple goals alongside one primary goal of following a vegetarian, vegan, or pescatarian diet would increase the achievability of that goal. Participants of this study were broken into two groups: currently following a plant-based diet (ADHERE) and striving to follow a plant-based diet (STRIVE). Researchers hypothesized that the number of health and/or diet related alternative goals set by participants would differ between the two groups, that the ADHERE group would report that their alternative goals were more helpful and less interfering in achieving their dietary goal than the STRIVE group, and that a higher rank of importance of the dietary goal would predict being in the ADHERE group. Results showed that the number of health and/or diet related alternative goals did not differ between groups. The ADHERE group and STRIVE group did not have significantly different helpfulness and interference reports. Although, in an exploratory analysis, it was shown that those participants who reported at least 2 health/diet related alternative goals found those goals to be significantly more helpful than those who reported 0 or 1 health/diet goal. Results showed that rank of dietary goal did not predict group assignment. Overall, the results from this study showed that the type of alternative goal was very important when pursuit of multiple goals was in effect. Type of alternative goal seemed to be a higher predictor of the perceived helpfulness of the alternative goals than previous achievement of goals.
ContributorsShilling, Katy (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Karoly, Paul (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2018
Description
Exposure to sun radiation (SUR) with ambient temperature may be an influencer on athletes’ sweat loss in different environments, but the results are not currently known. The purpose of this study was to determine the effects of SUR on fluid balance (FB) and hydration status (HS) in athletes exercising indoors and outdoors.
Initial FB and HS were assessed in NCAA-DI female soccer athletes (n=10) of a single team in temperate, dry conditions (55-68°F, 18-48% humidity) who were monitored during 3 practices of equal estimated energy expenditure (EE): two outdoors in direct SUR (cold/moderate temperatures) and one indoors without SUR (moderate temperatures). Humidity, temperature, and wet bulb globe temperature (WBGT – a measurement partly based on SUR, including ambient temperature/relative humidity) were recorded using Heat Stress Meters placed in the direct sun or in the shade. Each athlete’s semi-nude dry body weight was recorded before and after exercise. Urine samples were taken before, after, and the morning after. Urine specific gravity (USG) was tested to assess HS. Athletes wore combined heart rate and activity monitors to estimate EE and were provided ad libitum water and/or a zero-calorie sports drink. Their total intake included weights of consumed food and drink. Sweat rate was calculated using body weight change and intakes of liquids minus urine losses/hour.
Two-way repeated measures ANOVA analyzed group-level differences. No significance was found in total FB (1.01±0.32 L/hr) or EE/hr (444±97.1 kcal/hr) across all days (p>0.05). In analyzing individual athlete results, 40% had consistent USG >1.025 (p=0.001) suggesting potential dehydration. These 4 athletes selected water as their beverage, of which is known that consuming only water does not stimulate drinking behavior as does electrolyte drinks. The remaining 60% were overall not dehydrated (USG <1.025) but must be aware of incidental dehydration in hotter temperatures.
The conclusion is that in low-moderate temperatures, athletes self-regulate drinking habits and achieve fluid balance during exercise with or without sun radiation. However, athletes with average USG >1.025 are likely to remain dehydrated in moderate temperatures. The findings suggest that more education would benefit these athletes by ensuring hydration in any environment.
Initial FB and HS were assessed in NCAA-DI female soccer athletes (n=10) of a single team in temperate, dry conditions (55-68°F, 18-48% humidity) who were monitored during 3 practices of equal estimated energy expenditure (EE): two outdoors in direct SUR (cold/moderate temperatures) and one indoors without SUR (moderate temperatures). Humidity, temperature, and wet bulb globe temperature (WBGT – a measurement partly based on SUR, including ambient temperature/relative humidity) were recorded using Heat Stress Meters placed in the direct sun or in the shade. Each athlete’s semi-nude dry body weight was recorded before and after exercise. Urine samples were taken before, after, and the morning after. Urine specific gravity (USG) was tested to assess HS. Athletes wore combined heart rate and activity monitors to estimate EE and were provided ad libitum water and/or a zero-calorie sports drink. Their total intake included weights of consumed food and drink. Sweat rate was calculated using body weight change and intakes of liquids minus urine losses/hour.
Two-way repeated measures ANOVA analyzed group-level differences. No significance was found in total FB (1.01±0.32 L/hr) or EE/hr (444±97.1 kcal/hr) across all days (p>0.05). In analyzing individual athlete results, 40% had consistent USG >1.025 (p=0.001) suggesting potential dehydration. These 4 athletes selected water as their beverage, of which is known that consuming only water does not stimulate drinking behavior as does electrolyte drinks. The remaining 60% were overall not dehydrated (USG <1.025) but must be aware of incidental dehydration in hotter temperatures.
The conclusion is that in low-moderate temperatures, athletes self-regulate drinking habits and achieve fluid balance during exercise with or without sun radiation. However, athletes with average USG >1.025 are likely to remain dehydrated in moderate temperatures. The findings suggest that more education would benefit these athletes by ensuring hydration in any environment.
ContributorsOlzinski, Stephanie (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Yudell, Amber (Committee member) / Arizona State University (Publisher)
Created2019
Description
Cardiovascular disease has reached epidemic proportions resulting in its ranking as the number one cause of mortality in the Western world. A key player in the pathophysiology of vascular disease is oxidative stress due to free radical accumulation. This intervention study was conducted to evaluate any potential mediation of oxidative stress using a soil-derived organometallic compound (OMC) with suspected antioxidant properties. A 10-week study was conducted in male Sprague-Dawley rats (n = 42) fed either a high-fat diet (HFD) consisting of 60% kcal from fat or a standard Chow diet containing only 6% kcals from fat. Rats from each diet group were then subdivided into 3 subgroups (n = 6-10 each) that received 0.0 mg/mL, 0.6 mg/mL or 3.0 mg/mL OMC. Neither the diet nor OMC significantly changed protein expression of inducible nitric oxide synthase (iNOS) in isolated aortas. Plasma levels of the inflammatory marker, tumor necrosis factor alpha (TNFα) were below detection after the 10-week trial. Superoxide dismutase (SOD), a scavenger of the free radical, superoxide, was not significantly different following HFD although levels of SOD were significantly higher in Chow rats treated with 0.6 mg/mL OMC compared to HFD rats treated with the same dose (p < 0.05). Lipopolysaccharides (LPS) were significantly increased following 10 weeks of high fat intake (p < 0.05). This increase in endotoxicity was prevented by the high dose of OMC. HFD significantly increased fasting serum glucose levels at both 6 weeks (p < 0.001) and 10 weeks (p < 0.025) compared to Chow controls. The high dose of OMC significantly prevented the hyperglycemic effects of the HFD in rats at 10 weeks (p = 0.021). HFD-fed rats developed hyperinsulinemia after 10 weeks of feeding (p = 0.009), which was not prevented by OMC. The results of this study indicate that OMC may be an effective strategy to help manage diet-induced hyperglycemia and endotoxemia. However, further research is needed to determine the mechanism by which OMC helps prevent hyperglycemia as measures of inflammation (TNFα) and vascular damage (iNOS) were inconclusive.
ContributorsWatson, Deborah F (Author) / Sweazea, Karen L (Thesis advisor) / Johnston, Carol (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2018
Description
Chronic diseases, such as diabetes, heart disease, and cancer are leading causes of death in the United States. Although they result from a host of personal and environmental factors, diet remains a critical way to reduce the risk. Plant-based diets in particular are associated with reduction in risk for chronic disease due to an intake that closely mirrors the Dietary Guidelines for fruit and vegetable consumption, fiber, and fat intake. Additionally, plant-based diets offer a sustainable alternative in relation to food production as they often require fewer natural resources overall.
While there are many benefits to following a plant-based diet, potential concerns arise as well. Certain micronutrients can be lacking and protein intake can be inadequate without careful consideration of dietary intake. Protein is especially important for its role in maintaining lean body mass, which allows individuals to function in activities of daily living. Plant-based sources of protein are often less digestible; therefore, those consuming vegetarian and vegan diets may benefit from increased protein intake for preservation and perhaps improved lean body mass as well as strength changes.
Recent research has shown that vegetarians had significantly less muscle mass compared to omnivores despite similar amounts of protein intake in grams per day. Other research has shown that vegetarians do not necessarily see an increase in muscle mass when exposed to resistance exercise, whereas those following an omnivorous diet or lacto-ovo-vegetarian diet do. However, other studies have found that vegetarians can achieve increases in lean body mass comparable to omnivores if 30g/meal of plant-based protein is ingested consistently.
It remains unclear what effect protein supplementation might have on strength and muscle mass among sedentary plant-based eaters. As such, the present study assessed sedentary vegetarian and vegan individuals as to whether increases in dietary plant-based protein could elicit changes in body composition, hand grip and lower body strength independent of exercise. After an 8-week intervention, no significant differences for lean body mass or strength were noted. Results are discussed in the context of trial integrity and supplement consumption issues.
While there are many benefits to following a plant-based diet, potential concerns arise as well. Certain micronutrients can be lacking and protein intake can be inadequate without careful consideration of dietary intake. Protein is especially important for its role in maintaining lean body mass, which allows individuals to function in activities of daily living. Plant-based sources of protein are often less digestible; therefore, those consuming vegetarian and vegan diets may benefit from increased protein intake for preservation and perhaps improved lean body mass as well as strength changes.
Recent research has shown that vegetarians had significantly less muscle mass compared to omnivores despite similar amounts of protein intake in grams per day. Other research has shown that vegetarians do not necessarily see an increase in muscle mass when exposed to resistance exercise, whereas those following an omnivorous diet or lacto-ovo-vegetarian diet do. However, other studies have found that vegetarians can achieve increases in lean body mass comparable to omnivores if 30g/meal of plant-based protein is ingested consistently.
It remains unclear what effect protein supplementation might have on strength and muscle mass among sedentary plant-based eaters. As such, the present study assessed sedentary vegetarian and vegan individuals as to whether increases in dietary plant-based protein could elicit changes in body composition, hand grip and lower body strength independent of exercise. After an 8-week intervention, no significant differences for lean body mass or strength were noted. Results are discussed in the context of trial integrity and supplement consumption issues.
ContributorsIncollingo, April (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Johnston, Carol (Committee member) / Grgich, Traci (Committee member) / Arizona State University (Publisher)
Created2020
Description
Background: Higher intake of carbohydrates in the evening and later eating times has been associated with higher total energy intake (TEI)1-3 and higher risk of being overweight or obese.1,4 Though existing evidence indicates a link between added sugars intake and increased body mass index (BMI), the effect of daily patterns of added sugars intake on TEI and BMI is unknown. Research on added sugars has relied on self-report dietary assessments with limited days of dietary data, resulting in unreliable estimates. The purpose of this thesis was to describe patterns of added sugars consumption, and to investigate the relationship between dietary sugars, eating patterns, TEI, and BMI using 15-days of dietary data from a feeding study. Methods: 40 participants age 18 to 70 years completed a 15-d highly controlled feeding study which imitated their normal diet, while recording meal times. Meals and snacks were coded based on participant identified, time-of-day, and meal content specific criteria. All consumed foods and beverages were carefully weighed and entered into the Nutrition Data System for Research (NDSR) for analysis. Pearson correlation, independent t-test, one-way repeated measures analysis of variance (ANOVA) with post hoc tests, and multiple linear regressions were used to investigate the association between patterns of added sugars and energy intake, as well as eating frequency (EF), with TEI and BMI. Results: 15-d median added sugars intake was 9.7% of total calories. The highest contribution to added sugars intake (% of g/d) came from snacks (44%) in women and from afternoon (39%) consumption in men. The highest contribution to TEI came from dinner (30%) and afternoon (34%) consumption in women, and from lunch (31%) or dinner (30%) and afternoon (35%) consumption in men. Total eating occasion (EO) frequency had a negative association with TEI (r = -0.31) and no association with % energy from added sugars. In multivariate regression models, besides sex, % energy from beverages only (Adjusted R2 = 0.41) and % added sugars from dinner (Adjusted R2 = 0.39) were significant predictors of TEI, while none of the variables were associated with BMI. Conclusion: Changing one’s pattern of eating, (EF and % energy from beverages only and % added sugars from dinner), may reduce TEI, potentially reducing BMI.
ContributorsGunnerson, Hannah Marie (Author) / Tasevska, Natasha (Thesis advisor) / Johnston, Carol (Committee member) / Ohri-Vachaspati, Punam (Committee member) / Arizona State University (Publisher)
Created2019
Description
Urinary sucrose and fructose has been suggested as a predictive biomarker of total sugars intake based on research involving UK adults. The purpose of this study was to determine the association between total sugars consumption and 24-hour urinary sucrose and fructose (24uSF) in US adult population and to investigate the effect of physical activity on this association. Fifty seven free-living healthy subjects 20 to 68 years old, participated in a 15-day highly controlled feeding study, consuming their habitual diet, provided by the research metabolic kitchen. Dietary sugars were estimated using Nutrition Data System for Research (NDSR). Subjects collected eight 24-hour urine samples measured for urinary sucrose and fructose. Physical activity was assessed daily using a validated 15-day log that inquired about 38 physical activities across six domains; home activities, transportation, occupation, conditioning, sports and leisure. The mean total sugars intake and added sugars intake of the sample was 112.2 (33.1) g/day and 65.8 (29.0) g/day (9.7%EI), respectively. Significant moderate positive correlation was found between 15-d mean total sugars intake and 8-day mean 24uSF (r = 0.56, p < 0.001). Similarly, added sugars were moderately correlated with 24uSF (r = 0.56, p < 0.001), while no correlation was found between naturally-occurring sugars and 24uSF (r = 0.070, p < 0.001). In a linear multiple regression, total and added sugars each explained 30% of variability in 24uSF (Adjusted R2, p value; total sugars: 0.297, 0.001; added sugars: 0.301, p < 0.001). Physical activity had no effect on the association between dietary and urinary sugars in neither the correlation nor the linear regression analysis. 24uSF can be used as a biomarker for total and added sugars consumption in US adults, although its predictability was weaker compared to findings involving UK adults. No evidence was found showing that physical activity levels affect the association between 24uSF and total sugars intake in US adults. More detailed investigation through future feeding studies including subjects with wide range of sugars intake and of different ethnic/racial backgrounds are needed to better understand the characteristics of the biomarker and its uses.
ContributorsMohan, Chitra (Author) / Tasevska, Natasha (Thesis advisor) / Ainsworth, Barbara (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2019