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Vegetarian diets can provide an abundance of nutrients when planned with care. However, research suggests that vegetarian diets may have lower protein quality than omnivore diets. Current protein recommendations assume that vegetarians obtain a majority of their protein from animal products, like dairy and eggs. Studies have shown that this

Vegetarian diets can provide an abundance of nutrients when planned with care. However, research suggests that vegetarian diets may have lower protein quality than omnivore diets. Current protein recommendations assume that vegetarians obtain a majority of their protein from animal products, like dairy and eggs. Studies have shown that this assumption may not be valid. The recommended dietary allowance (RDA) may not be adequate in vegetarian populations with high protein requirements. The purpose of this study is to analyze dietary protein quality using the DIAAS (Digestible Indispensable Amino Acid Score) method in both vegetarian and omnivore endurance athletes. 38 omnivores and 22 vegetarians submitted 7-day food records which were assessed using nutrition analysis software (Food Processor, ESHA Research, Salem, OR, USA). Dietary intake data was used to calculate DIAAS and determine the amount of available dietary protein in subject diets. Dietary data was compared with the subjects’ lean body mass (obtained using DEXA scan technology), and strength (quantified using peak torque of leg extension and flexion using an isokinetic dynamometer). Statistical analyses revealed significantly higher available protein intake in the omnivore athletes (p<.001). There were significant correlations between available protein intake and strength (p=.016) and available protein intake and lean body mass (p<.001). Omnivore subjects had higher lean body mass than vegetarian subjects (p=.011). These results suggest that vegetarian athletes may benefit from higher overall protein intakes to make up for lower dietary protein quality.
ContributorsZuelke, Corinne (Author) / Johnston, Carol (Thesis advisor) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Dixon, Kathleen (Committee member) / Arizona State University (Publisher)
Created2017
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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

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
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Epidemiological studies have identified obesity as a risk factor for numerous chronic diseases such as adult onset diabetes, hypertension, and hypercholesterolemia. In both humans and laboratory animals, high-fat diets have been shown to cause obesity. Increases in dietary fat lead to increased energy consumption and, consequently, significant increases in body

Epidemiological studies have identified obesity as a risk factor for numerous chronic diseases such as adult onset diabetes, hypertension, and hypercholesterolemia. In both humans and laboratory animals, high-fat diets have been shown to cause obesity. Increases in dietary fat lead to increased energy consumption and, consequently, significant increases in body fat content. CD36 has been implicated in fat perception, preference, and increased consumption, but it is yet to be tested using a behavior paradigm. To study the effect of CD36 on fat taste transmission and fat consumption, four CD36 knockout (experimental) mice and four Black 6 wildtype (control) mice underwent 20 days of fat preference and perception testing. Both groups of mice were exposed to foods with progressively increasing fat content (10%, 12.5%, 15% 17.5%, 20%, 45%) in order to assess the effect of CD36 on fat preference. Afterward, the mice were subjected to an aversive conditioning protocol designed to test the effect of CD36 on fat taste perception; development of a conditioned taste aversion was indicative of ability to taste fat. Especially, knockout mice exhibited diminished preference for and reduced consumption of fat during preference testing and were unable to identify fat taste as the conditioned stimulus during aversive conditioning. A repeated measures ANOVA with Bonferroni correction revealed a significant main effect of group on fat consumption, energy intake, and weight. Linear regression revealed CD36 status to account for a majority of observed variance in fat consumption across both phases of the experiment. These results implicate CD36 in fat taste perception and preference and add to the growing body of evidence suggesting fat as a primary taste.
ContributorsJasbi, Paniz (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Wadhera, Devina (Committee member) / Arizona State University (Publisher)
Created2018
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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

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.
ContributorsOlzinski, Stephanie (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Yudell, Amber (Committee member) / Arizona State University (Publisher)
Created2019
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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

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
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Description
ABSTRACT



Many natural interventions have been effective at lowering postprandial glucose concentrations (PPG) in research trials and, theoretically, should have favorable effects on the prevention and management of T2DM. Natural interventions include vinegar, nuts and exercise. Green tea has been demonstrated to also possessing antiglycemic effects. Thus, green

ABSTRACT



Many natural interventions have been effective at lowering postprandial glucose concentrations (PPG) in research trials and, theoretically, should have favorable effects on the prevention and management of T2DM. Natural interventions include vinegar, nuts and exercise. Green tea has been demonstrated to also possessing antiglycemic effects. Thus, green tea, and its most abundant catechin EGCG, are being consumed for its potential health benefits in cancer prevention and in its inhibitory effects on α-amylase. Many studies have found EGCG to inhibit α-amylase an enzyme needed in the breakdown of carbohydrates (CHO). Other studies have looked at EGCG and its potential for lowering PPG concentrations due to its inhibitory effects on α-amylase in both mice and humans. Yet there is no research on Matcha tea specifically. Matcha tea is green tea in powder form; hence, it is consumed in its entirety unlike traditional teas which are steeped in bags. The purpose of this study was to determine whether Macha tea impacts PPG concentrations in healthy adults. Twelve subjects completed this randomized controlled, single blinded, crossover study. On three separate occasions the twelve subjects consumed a bagel and jam with either water, Lipton green tea, or Macha tea. Fasting blood glucose was taken upon their arrival. Once the tea or water and bagel with jam were consumed PPG concentrations were measured every 30 minutes until 120 minutes were reached. Results showed no statistically significant effects on PPG concentrations in either test groups (p=.960). However, this study did not measure EGCG levels in the tea provided. Therefore, further research should be done with known EGCG amounts to see its effects on PPG concentrations to fully rule out its potential.
ContributorsRomash, Roni (Author) / Johnston, Carol (Thesis advisor) / Dixon, Kathleen (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2018
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Description
The true number of food borne illness occurrences that stem from the home is largely unknown, but researchers believe the number is much greater than represented in national data. The focus on food safety has generally been directed at food service establishments, which have made great strides at improving the

The true number of food borne illness occurrences that stem from the home is largely unknown, but researchers believe the number is much greater than represented in national data. The focus on food safety has generally been directed at food service establishments, which have made great strides at improving the methods of how their food is prepared. However, that same drive for proper food safety education is lacking in home kitchens, where the majority of food is prepared. Young adults are among some of the riskiest food preparers, and limited research and education methods have been tested on this vulnerable population. This study examined the effect of a basic food safety intervention on consumer food safety knowledge in young adults in the United States (U.S.) over a week period. The study had a pre/post survey design, where participants answered a survey, watched a short 10-minute video, and then recompleted the same survey a week later. Ninety-one participants age 18-29 years completed the initial food safety knowledge questionnaire. Twenty-six of those participants completed both the pre- and post-intervention food safety knowledge questionnaires. A paired t-test was used to analyze changes in questionnaire scores pre/post intervention. The majority of participants were female (78.9%), Arizona State University (ASU) students (78.0%), did not have any formal food safety education (58.2%), prepared a minimum of one meal per week from home (96.7%), and had completed 0-1 college nutrition courses (64.8%). The average overall score for all participants who completed the initial questionnaire was 62.6%. For those that took both the initial questionnaire and the follow up questionnaire (n=26), their scores shifted from 66.8% to 65.5% after the intervention. Scores increased significantly only for one question post-intervention: 38.5% (n=10) to 53.8% (n=14) for the safest method for cooling a large pot of hot soup (p = 0.050). This was the first study of its kind to test a video intervention in attempts to increase food safety knowledge in young adults, and additional studies must be done to solidify the results of this study. Other means of education should be explored as well to determine the best way of reaching this population and others.
ContributorsClifford, Brooke (Author) / Johnston, Carol (Thesis advisor) / Grgich, Traci (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2019
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Description
Background: The Academy of Nutrition and Dietetics states that it is possible for a vegetarian to obtain the recommended amount of nutrients with a properly planned diet but nutrient deficiencies, such as vitamin B12 deficiency, may occur if diet planning is not optimal. An early indicator of B12 deficiency is

Background: The Academy of Nutrition and Dietetics states that it is possible for a vegetarian to obtain the recommended amount of nutrients with a properly planned diet but nutrient deficiencies, such as vitamin B12 deficiency, may occur if diet planning is not optimal. An early indicator of B12 deficiency is raised homocysteine concentrations in blood which can cause health issues.

Objective: The amino acid methionine is consumed via dietary protein. Methionine is used in the biosynthesis of other proteins. After a removal of a methyl group, it makes homocysteine. Slightly raised homocysteine may promote greater synthesis of glutathione, an important endogenous antioxidant protectant. It can then be recycled back into methionine or converted into cysteine with the addition of various B-vitamins such as vitamin B12, folic acid, and vitamin B6. Cysteine then uses outside sources of glutamate and glycine to create glutathione (GSH). With the catalyst glutathione peroxidase it donates an electron and becomes the oxidized form, glutathione disulfide (GSSG). It can then convert back to GSH with the aid of glutathione reductase by using the reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) as an electron donor. This study will examine glutathione levels in omnivores and vegetarians and see if it is related to vitamin B12 and homocysteine levels.

Design: This cross-sectional study encompassed 16 omnivores and 17 vegetarians from Phoenix, Arizona. A vegetarian diet was defined as one that excludes red meat, poultry, pork and seafood but allows dairy products and/or eggs; the diet had to be followed for at least one year. An omnivore diet is defined as eats meat daily. Participants completed a diet questionnaire and a vitamin B12, B6 and folate food questionnaire and provided a fasting blood sample.

Results: The mean plasma B12 and homocysteine did not differ between diet groups. Glutathione was significantly lower among vegetarians in comparison to omnivores, 1.9±0.5 and 2.3±0.7 mmol respectively (p=0.046).

Conclusions: The hypothesis was shown to be incorrect that vegetarians would have a higher glutathione level than omnivores as a result of their modest consumption of vitamin B12. The implications of a reduced glutathione status are discussed.
ContributorsManley, Rachel Christine (Author) / Johnston, Carol (Thesis advisor) / Levinson, Simin (Committee member) / Barth, Christina (Committee member) / Arizona State University (Publisher)
Created2019
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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

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.
ContributorsIncollingo, April (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Johnston, Carol (Committee member) / Grgich, Traci (Committee member) / Arizona State University (Publisher)
Created2020
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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

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