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Description
ABSTRACT Vitamin C plays an important role in fatty acid metabolism because it is required for carnitine synthesis. Vitamin C has been shown to have an inverse relationship with weight and body fat percent in a number of studies. However, there has been limited research exploring the relationship between vitamin C status and fat oxidation. This cross-sectional study investigates the relationship between plasma vitamin C and fat oxidation in 69 participants and between plasma vitamin C and body fatness in 82 participants. Participants were measured for substrate utilization via indirect calorimetry while at rest and measured for body fatness via DEXA scan. Participants provided a single fasting blood draw for analysis of plasma vitamin C. Results did not show a significant association between vitamin C and fat oxidation while at rest, therefore the data do not support the hypothesis that vitamin C status affects fat oxidation in a resting state. However, a significant inverse association was found between vitamin C and both total body fat percent and visceral fat.
ContributorsObermeyer, Lindsay (Author) / Johnston, Carol (Thesis advisor) / Hall, Rick (Committee member) / Swan, Pamela (Committee member) / Arizona State University (Publisher)
Created2014
Description
Vitamin C is a micronutrient with many important physiological roles. It can function as a reducing agent, a free radical scavenger, and an enzyme cofactor. Much research has examined the potential of vitamin C supplements to enhance exercise capacity in trained athletes; however, little is known regarding the effects of vitamin C supplements on the promotion of leisure-time physical activity in the general population. This area deserves attention since 1/3 of Americans have below adequate vitamin C status, and since aversion to exercise, fatigue, and altered mood states are the earliest signs of poor vitamin C status. This study analyzed the effect of supplementing 500 mg twice daily of vitamin C on self-reported leisure-time activity levels and mood states in young men. Twenty-nine healthy, young men, aged 18-35 years, were stratified by age, BMI, smoking status, and plasma vitamin C concentrations and assigned to either a control (CON) or experimental group (VTC) for the 8-week randomized, double-blinded, parallel arm trial. Subjects were instructed to keep track of their leisure-time physical activity by filling out the validated Godin Leisure-Time Exercise Questionnaire weekly for the entire study. In addition, subjects took the self-administered Profile of Mood States (POMS) at baseline, week 4, and week 8 to observe mood states. Plasma vitamin C concentrations were analyzed at the initial screening, week 4, and week 8 of the study. Plasma vitamin C concentrations significantly differed by group at week 4 and week 8. Furthermore, vitamin C supplementation significantly increased self-reported mild, moderate, and strenuous activity levels during the 8-week trial. Overall, total physical activity scores increased nearly 50% in the VTC group as compared to 18% in the CON group (p=0.001). However, mood states were not significantly impacted by vitamin C supplementation during the trial. This study provides the first experimental evidence that supplementing 500 mg of vitamin C twice daily can be effective in increasing leisure-time physical activity in healthy young men. This study, however, was unable to link improvements in physical activity rates to improved mood states. Since sedentary behaviors have been implicated in the rise of obesity in the U.S., further research should be conducted to substantiate the finding that vitamin C supplementation increases physical activity.
ContributorsSchumacher, Sarah (Author) / Johnston, Carol (Thesis advisor) / Appel, Christy (Committee member) / Swan, Pamela (Committee member) / Arizona State University (Publisher)
Created2012
Description
Nut consumption, specifically almonds, have been shown to help maintain weight and influence disease risk factors in adult populations. Limited studies have been conducted examining the effect of a small dose of almonds on energy intake and body weight. The objective of this study was to determine the influence of pre-meal almond consumption on energy intake and weight in overweight and obese adults. In this study included 21, overweight or obese, participants who were considered healthy or had a controlled disease state. This 8-week parallel arm study, participants were randomized to consume an isocaloric amount of almonds, (1 oz) serving, or two (2 oz) cheese stick serving, 30 minutes before the dinner meal, 5 times per week. Anthropometric measurements including weight, waist circumference, and body fat percentage were recorded at baseline, week 1, 4, and 8. Measurement of energy intake was self-reported for two consecutive days at week 1, 4 and 8 using the ASA24 automated dietary program. The energy intake after 8 weeks of almond consumption was not significantly different when compared to the control group (p=0.965). In addition, body weight was not significantly reduced after 8 weeks of the almond intervention (p=0.562). Other parameters measured in this 8-week trial did not differ between the intervention and the control group. These data presented are underpowered and therefore inconclusive on the effects that 1 oz of almonds, in the diet, 5 per week has on energy intake and bodyweight.
ContributorsMcBride, Lindsey (Author) / Johnston, Carol (Thesis advisor) / Swan, Pamela (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2011
Description
The popularization of energy drink use as a supplement to exercise is steadily increasing, especially among young adult males. However, the effects of energy drinks on muscular performance in young adults have yet to be clearly elucidated. Eight male subjects (mean age: 23.3 ± 4.3 yrs, height: 181.0 ± 5.3 cm, fat percent 17.8 ± 5.2%, and weight 85.3 ± 12.6 kg) completed this randomized double-blinded cross over study. The purpose of this study was to determine differences in acute muscular strength and endurance and Profile of Mood States (POMS) scores between three treatments (RockStar, sugar-free RockStar, and sugar-free caffeine-free Placebo). It was hypothesized that there would be no significant differences in acute peak torque and endurance of the knee extensors and flexors or on fatigue and vigor subscores from the POMS questionnaire. Each man was tested randomly at least 1 week apart. Diet and time of day were held constant across trials. Peak torque of knee extensors and flexors at 60, 180, 240 degress/second and fatigue index and total work were calculated by performing 50 repetitions at 240 degrees/second. There were no significant differences in peak torque, fatigue index, or total work measures or in subjective measures of fatigue or vigor from the POMS between the treatments. This study indicates that RockStar energy drinks have no acute ergogenic effects in young men performing isokinetic strength or endurance testing.
ContributorsHawley, Michelle (Author) / Swan, Pamela (Thesis advisor) / Campbell, Kathryn (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2012
Description
Most American children consume less than the recommend amount of fruits and vegetables (F&V), 74% and 84%, respectively. Eating too few F&V in childhood is associated with increased risk of cardiovascular disease, hypertension, respiratory symptoms, and some cancers later in life. Adequate F&V consumption favorably impacts antioxidant status, gut flora, mood, and cognitive functioning. Nutrients such as vitamin C and fiber are only naturally occurring in plant foods. For many children, school lunches are an important source of F&V. This pilot study assessed the feasibility of providing condiments to increase children’s consumption of salad bar F&V in an elementary school cafeteria at lunchtime. The trial site was a single Title 1 elementary school in a large, urban district in the greater Phoenix metropolitan area. Taste tests were conducted on three convenience samples of children in grades 3 – 7, aged 8 – 12 years (n=57) to identify the most popular condiment flavors. The five highest rated flavors were made available daily at a “flavor station” in the school’s lunchroom for three consecutive weeks during the Fall 2018 semester. Descriptive and inferential statistics were used to analyze data. A cost analysis was conducted for capital outlays related to the flavor station. School employee perceptions of F&V and the flavor station were assessed via posttest online surveys. Peanut butter was rated the best tasting condiment by children and was the only condiment that increased in popularity throughout the intervention. Overall, daily F&V consumption increased 17 g per child. There was a linear increase in F&V consumption during the study (r=0.986; P=0.014). As a proportion of the total F&V selected, F&V waste decreased by nearly 3%. The average daily cost of providing the flavor station was $0.09 per student. Sixty-five percent of school staff felt that the flavor station should continue at their school. Peanut butter is an affordable, nutrient-dense food that accommodates the USDA Food and Nutrition Service meal patterns and nutrition standards, and thus, is a viable strategy for increasing F&V consumption and decreasing F&V waste. The results herein inform the development of future interventions to improve the palatability of F&V for children.
ContributorsScholtz, Cameron (Author) / Johnston, Carol (Thesis advisor) / Alexon, Christy (Committee member) / Hooker, Steven (Committee member) / Schwake, David (Committee member) / Swan, Pamela (Committee member) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Arizona State University (Publisher)
Created2019
Description
Due to persistent undernutrition in India and the increased demands placed on a woman’s body during childbearing and lactation, the Indian government has implemented a program to provide supplemental nutrition packets to women in rural India. This study examines the factors influencing uptake of nutritional packets by lactating mothers in southern, rural Rajasthan. Women were recruited from 65 villages in Rajasthan, India (n=149, minimum of 2 per village) to evaluate the relationship of nutrition packet uptake and two factors--education levels and distance to the health center.
Level of education had little impact on whether or not women received the nutrition packet. Of those women with no education, 63.1% received the packet. Of those with any education, 63.9% got the packet.
In contrast, distance was strongly correlated with whether or not women received the packet. For example, of the women living within 200 meters of the health center, 93.2% received a nutrition packet. Of the women living between 250 meters and one kilometer of the health center, 68.4% received a nutrition packet. Of the women living over one kilometer from the health center, only 25% received a nutrition packet. The relationship between uptake of packets and women’s perception of distance to the health center was also explored. Out of 50 women who did not receive the packet, all of the women who said there was no health center in their village did live more than one kilometer from a health center. Of the women who lived between 250 meters and one kilometer from the health center, 40% felt it was too far. Of the women who lived more than a kilometer from the health center, 66.7% felt it was too far and 29.6% said there was no health center in their village. Again, it does not appear that ‘too far’ is just a default reason for women, but that actual distance, more so than education, is a major contributing factor in their ability to take the nutrition packet. These findings suggest that improving access to supplemental nutrition packets at the village level may increase uptake by the women.
Level of education had little impact on whether or not women received the nutrition packet. Of those women with no education, 63.1% received the packet. Of those with any education, 63.9% got the packet.
In contrast, distance was strongly correlated with whether or not women received the packet. For example, of the women living within 200 meters of the health center, 93.2% received a nutrition packet. Of the women living between 250 meters and one kilometer of the health center, 68.4% received a nutrition packet. Of the women living over one kilometer from the health center, only 25% received a nutrition packet. The relationship between uptake of packets and women’s perception of distance to the health center was also explored. Out of 50 women who did not receive the packet, all of the women who said there was no health center in their village did live more than one kilometer from a health center. Of the women who lived between 250 meters and one kilometer from the health center, 40% felt it was too far. Of the women who lived more than a kilometer from the health center, 66.7% felt it was too far and 29.6% said there was no health center in their village. Again, it does not appear that ‘too far’ is just a default reason for women, but that actual distance, more so than education, is a major contributing factor in their ability to take the nutrition packet. These findings suggest that improving access to supplemental nutrition packets at the village level may increase uptake by the women.
ContributorsJeffers, Eva Marie (Author) / Hruschka, Daniel (Thesis director) / Maupin, Jonathan (Committee member) / Cook, Jeffrey (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2015-05
Description
Currently, there has been limited research on evaluating the social media use and
competency level of registered dietitian
utritionists (RD/N). With health information increasingly sought on social media, it is imperative to understand the social media competency of health professionals. The social media use, reach, and competency level of a nationwide RD/N sample was assessed utilizing an online survey. The sample (n=500) while mostly female (97%) was representative of RD/Ns compared to the nationwide statistics from the Commission on Dietetic Registration. The sample included RD/Ns from forty-six states with California (n=44), New York (n=42), and Texas (n=34) having the largest proportion of respondents. The majority of RD/Ns engage in social media for personal use (92.4%) and 39.2% engage for professional use. One hundred and twenty-five RD/Ns reported 777 ± 1063 (mean ± SD) social media followers. As compared to non-millennial RD/Ns, millennial RD/Ns engaged significantly more in social media for personal and professional use (+10% and +13.5% respectively, p<0.001) and scored significantly higher for social media competency (p<0.001). Additionally, food and nutrition management and consultant/private practice/industry RD/Ns had significantly higher competency scores than clinical RD/Ns (p=0.015 and p=0.046, respectively). RD/Ns who use social media personally and professionally had a significantly higher competency score than RD/Ns who did not (p<0.001). There were significant associations of Facebook, Twitter, total followers and total average followers with the social media competency score (r=0.265, 0.404, 0.338, & 0.320, respectively) in RD/Ns. Specifically, the social media competency score, was found to explain 16% of the variation in the number of Twitter followers and 10% of the variation in the average number of followers by platform. These data suggest an opportunity to increase RD/Ns’ social media reach (i.e. following) by improving competency level.
competency level of registered dietitian
utritionists (RD/N). With health information increasingly sought on social media, it is imperative to understand the social media competency of health professionals. The social media use, reach, and competency level of a nationwide RD/N sample was assessed utilizing an online survey. The sample (n=500) while mostly female (97%) was representative of RD/Ns compared to the nationwide statistics from the Commission on Dietetic Registration. The sample included RD/Ns from forty-six states with California (n=44), New York (n=42), and Texas (n=34) having the largest proportion of respondents. The majority of RD/Ns engage in social media for personal use (92.4%) and 39.2% engage for professional use. One hundred and twenty-five RD/Ns reported 777 ± 1063 (mean ± SD) social media followers. As compared to non-millennial RD/Ns, millennial RD/Ns engaged significantly more in social media for personal and professional use (+10% and +13.5% respectively, p<0.001) and scored significantly higher for social media competency (p<0.001). Additionally, food and nutrition management and consultant/private practice/industry RD/Ns had significantly higher competency scores than clinical RD/Ns (p=0.015 and p=0.046, respectively). RD/Ns who use social media personally and professionally had a significantly higher competency score than RD/Ns who did not (p<0.001). There were significant associations of Facebook, Twitter, total followers and total average followers with the social media competency score (r=0.265, 0.404, 0.338, & 0.320, respectively) in RD/Ns. Specifically, the social media competency score, was found to explain 16% of the variation in the number of Twitter followers and 10% of the variation in the average number of followers by platform. These data suggest an opportunity to increase RD/Ns’ social media reach (i.e. following) by improving competency level.
ContributorsThompson-Felty, Claudia (Author) / Johnston, Carol (Thesis advisor) / Swan, Pamela (Committee member) / Lespron, Christy (Committee member) / Thornton, Leslie-Jean (Committee member) / Lee, Chong (Committee member) / Arizona State University (Publisher)
Created2017
Description
This study addresses the problem of high school graduates with learning disabilities who are unprepared for higher education and the workplace because of limited exposure to career professionals and perceived barriers. The purpose of this study is to examine how a career exploration model, entitled CaMPs (Career Model Professionals) influences students’ career decision-making self-efficacy. CaMPs incorporates exposure to career role models, as well as career research and self-reflection. CaMPs proivides students with learning disabilities first-hand accounts of successful career professionals, to assist them in setting academic and career goals that are aligned to their personal strengths. This mixed methods study develops and evaluates a career based innovation for high school students and reviews the relationship between the innovation and students’ self-efficacy. Students completed a self-efficacy survey (Career Decision Self-Efficacy - Short Form: CDSE) before and after the implementation of the CaMPs program. A t-test comparing pre- and post-survey scores indicated that there was a significant increase in self-efficacy after completion of the program. Qualitative data revealed changes in students’ career interests and new considerations to their career preparation process after participating in the CaMPs innovation. This study will be useful in the development of career programs for high school students, particularly those with learning disabilities, to assist them in choosing and preparing for their future careers.
ContributorsCook, Jeffrey (Author) / Caterino, Linda C (Thesis advisor) / Carlson, David L. (Committee member) / Dawes, Mary E (Committee member) / Arizona State University (Publisher)
Created2017
Description
While literature has examined the associations between emotions and overeating, rarely is the relationship between emotions and food choices included. The purpose of this secondary data analysis was to utilize mobile-based ecological momentary assessment (EMA) surveys to determine the associations among negative, positive, apathetic, and mixed emotions and a variety of food choices in college freshmen living in residence halls. A total of 2142 survey responses from 647 college freshmen were included in this analysis (70.3% female, 51.5% non-white). Mixed model logistic regression assessed the cross-sectional association between emotions and food choices adjusting for gender, race/ethnicity, Pell grant status, highest parental education, and the clustering of repeated measures within person and of students within residence hall. There were no significant associations between negative emotions and food choices. Positive emotions were significantly and inversely associated with eating pizza/fast food (OR=0.6; 95% CI=0.5, 0.8) and cereals (OR=0.6; 95% CI=0.4, 1.0), while apathetic emotions were significantly and positively associated with consuming salty snacks/fried foods (OR=1.6; 95% CI=1.1, 2.5) and inversely associated with consuming sandwiches/wraps (OR=0.5; 95% CI=0.3, 0.8) and meats/proteins (OR=0.6; 95% CI=0.4, 1.0). It was also found that there were several instances of surveys with mixed emotions, in which participants reported feeling two conflicting emotions at once (i.e. positive and negative). Mixed emotions were significantly associated with consuming sweets (OR=1.6; 95% CI=1.2, 2.1), meats/proteins (OR=1.6; 95% CI=1.2, 2.0), and cereals (OR=1.9; 95% CI=1.2, 2.9). Understanding the relationships between different types of emotions and food choices is helpful in understanding the motivation behind healthy versus unhealthy food choices. These findings can be used to develop interventions that encourage positive emotions in college freshmen to better promote healthy food choices and ultimately reduce the risk of weight gain and other health disparities. Future research should examine how college freshmen differ from other college students (i.e. upper classmen and graduate students), particularly related to their emotions and food choices, so that dietary interventions can be better suited to those who are vulnerable.
ContributorsAshurst, Jessica (Author) / Bruening, Meg (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Swan, Pamela (Committee member) / Arizona State University (Publisher)
Created2016
Description
Sustainability, as it relates to nutrition, affects all aspects of food from systems-level production to consumption. Viability of local food systems in the southwest of the United States has been largely understudied. In order to address this gap in the literature, semi-structured interviews were conducted with 20 farmers in Arizona and New Mexico to determine best practices, challenges and barriers to farming. Interviews were recorded, transcribed, and coded for themes. Many trends were consistent with those reported elsewhere in the US, but the importance of water emerged, a unique need not explicitly noted in other regional studies.
Vegetarian diets are typically more sustainable than omnivorous ones due to using less environmental resources in the production of food. An important consideration with plant protein and vegetarian diets, however, is whether this would affect athletic performance. To examine this, 70 male and female endurance athletes were compared for maximal oxygen uptake (VO2 max), peak torque when doing leg extensions, and body composition. Vegetarians had higher VO2 max, but peak torque was not significantly different by diet. Omnivores had higher total body mass, lean body mass, and there was a trend for peak torque to be higher.
To investigate whether plant-protein can comparably support development of lean body mass and strength development in conjunction with strength training, 61 healthy young males and females began a 12-week training and protein supplementation study. While previous training studies have shown no differences for lean body mass or strength development when consuming either soy (plant) or whey (animal) protein supplements in very large amounts (>48 grams), when consuming around 15-20 grams, whey has contributed to greater lean body mass accrual, although strength increases remain similar. The present study matched supplements by leucine content instead of by total protein amount since leucine has been shown to be a key stimulator of muscle protein synthesis and is more concentrated in animal protein. There were no significant differences between the whey or soy group for lean body mass or strength development, as assessed using isokinetic dynamometry doing leg extensions and flexions.
Vegetarian diets are typically more sustainable than omnivorous ones due to using less environmental resources in the production of food. An important consideration with plant protein and vegetarian diets, however, is whether this would affect athletic performance. To examine this, 70 male and female endurance athletes were compared for maximal oxygen uptake (VO2 max), peak torque when doing leg extensions, and body composition. Vegetarians had higher VO2 max, but peak torque was not significantly different by diet. Omnivores had higher total body mass, lean body mass, and there was a trend for peak torque to be higher.
To investigate whether plant-protein can comparably support development of lean body mass and strength development in conjunction with strength training, 61 healthy young males and females began a 12-week training and protein supplementation study. While previous training studies have shown no differences for lean body mass or strength development when consuming either soy (plant) or whey (animal) protein supplements in very large amounts (>48 grams), when consuming around 15-20 grams, whey has contributed to greater lean body mass accrual, although strength increases remain similar. The present study matched supplements by leucine content instead of by total protein amount since leucine has been shown to be a key stimulator of muscle protein synthesis and is more concentrated in animal protein. There were no significant differences between the whey or soy group for lean body mass or strength development, as assessed using isokinetic dynamometry doing leg extensions and flexions.
ContributorsLynch, Heidi (Author) / Wharton, Christopher M (Thesis advisor) / Johnston, Carol (Committee member) / Dickinson, Jared (Committee member) / Buman, Matthew (Committee member) / Swan, Pamela (Committee member) / Ransdell, Lynda (Committee member) / Arizona State University (Publisher)
Created2017