Matching Items (11)
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- All Subjects: vegetarian
- All Subjects: Hydration
- Creators: Johnston, Carol
- Member of: ASU Electronic Theses and Dissertations
- Resource Type: Text
Description
Dietary protein is known to increase postprandial thermogenesis more so than carbohydrates or fats, probably related to the fact that amino acids have no immediate form of storage in the body and can become toxic if not readily incorporated into body tissues or excreted. It is also well documented that subjects report greater satiety on high- versus low-protein diets and that subject compliance tends to be greater on high-protein diets, thus contributing to their popularity. What is not as well known is how a high-protein diet affects resting metabolic rate over time, and what is even less well known is if resting metabolic rate changes significantly when a person consuming an omnivorous diet suddenly adopts a vegetarian one. This pilot study sought to determine whether subjects adopting a vegetarian diet would report decreased satiety or demonstrate a decreased metabolic rate due to a change in protein intake and possible increase in carbohydrates. Further, this study sought to validate a new device called the SenseWear Armband (SWA) to determine if it might be sensitive enough to detect subtle changes in metabolic rate related to diet. Subjects were tested twice on all variables, at baseline and post-test. Independent and related samples tests revealed no significant differences between or within groups for any variable at any time point in the study. The SWA had a strong positive correlation to the Oxycon Mobile metabolic cart but due to a lack of change in metabolic rate, its sensitivity was undetermined. These data do not support the theory that adopting a vegetarian diet results in a long-term change in metabolic rate.
ContributorsMoore, Amy (Author) / Johnston, Carol (Thesis advisor) / Appel, Christy (Thesis advisor) / Gaesser, Glenn (Committee member) / Arizona State University (Publisher)
Created2012
Description
In 2002, a scientifically derived food guide pyramid for vegetarians, the Modified Food Guide for Lacto-ovo-vegetarians and Vegans was published and well received. Now that 10 years have passed, new scientific literature regarding the bioavailability of the nutrients of key concern in vegetarian diets has been published, and the graphical format of the nation's food guide has evolved from a pyramid shape into a circular plate. The objective of this research was to examine the post-2002 literature regarding the bioavailability of key nutrients in vegetarian diets; to use this information to update the recommendations made in the 2002 Modified Food Guide Pyramid for Lacto-ovo-vegetarians and Vegans; and to adapt this revised food plan to the new USDA MyPlate format. This process involved reviewing the scientific literature to determine if the DRIs for the nutrients of key concern in vegetarian diets are adequate for the vegetarian population and using this information to develop new recommendations for vegetarians if necessary, analyzing the nutrient content of representative foods in different food groups, reconfiguring the food groups so that foods with like nutrient components were grouped together, determining the number of servings of each food group required to meet vegetarians' nutrient requirements at three caloric levels, and developing sample menus. A circular plate graphic, the Vegetarian Plate, was designed to illustrate the recommendations of this updated food guide. This updated, scientifically derived food guide provides a sound base for diet planning for lacto-ovo-vegetarians and vegans. Further research is needed to assess the Vegetarian Plate's adequacy for children, pregnant and lactating women, athletes, and individuals with medical conditions or chronic diseases.
ContributorsFladell, Lauren (Author) / Johnston, Carol (Thesis advisor) / Vaughan, Linda (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2013
Description
Diet quality is closely intertwined with overall health status and deserves close examination. Healthcare providers are stretched thin in the current stressed system and would benefit from a validated tool for rapid assessment of diet quality. The Rapid Eating and Activity Assessment for Participants Short Version (REAP-S) represents one such option. The objective of the current study was to evaluate the effectiveness of the REAP-S and Healthy Eating Index 2010 (HEI-2010) for scoring the diet quality of omnivorous, vegetarian and vegan diets. Eighty-one healthy male and female subjects with an average age of 30.9 years completed the REAP-S as well as a 24-hour dietary recall. REAP-S and HEI-2010 scores were calculated for each subject and evaluated against each other using Spearman correlations and Chi Square. Further analysis was completed to compare diet quality scores of the HEI-2010 and REAP-S by tertiles to examine how closely these two tools score diet quality. The mean HEI-2010 score was 47.4/100 and the mean REAP-S score was 33.5/39. The correlation coefficient comparing the REAP-S to the HEI-2010 was 0.309 (p=0.005), and the REAP-S exhibited a precision of 44.4% to the HEI-2010 for diet quality. The REAP-S significantly correlated with the HEI-2010 for whole fruit (r=0.247, p=0.026), greens and beans (r=0.276, p=0.013), seafood proteins (r=0.298, p=0.007), and fatty acids (r=0.400, p<0.001). When evaluated by diet type, the REAP-S proved to have increased precision in plant-based diets, 50% for vegetarian and 52% for vegan, over omnivorous diets (32%). The REAP-S is a desirable tool to rapidly assess diet quality in the community setting as it is significantly correlated to the HEI-2010 and requires less time, labor and money to score and assess than the HEI-2010. More studies are needed to evaluate the precision and validity of REAP-S in a broader, more diverse population.
ContributorsBliss, Courtney (Author) / Johnston, Carol (Thesis advisor) / Tasevska, Natasha (Committee member) / Levinson, Simin (Committee member) / Arizona State University (Publisher)
Created2015
Description
Water makes up about 45-70% of a human body's total weight. It is estimated that 80% of the human brain's tissue is composed of water. Cognitive productivity is altered when the body is in a mere 2% dehydrated state. Several cognitive functions impacted by dehydration include: visual motor tracing, short-term recall, attentiveness, and mathematic efficiency. It is estimated that 80% of the U.S. adult population endures the majority of their day in a mildly dehydrated state.
Participants were employees working full-time jobs with Arizona State University or Tri Star Motor Company. Employees had to be 18 or older were invited to join the study. Employees participating in the study lived within the the greater Phoenix area. Participants of all races, genders, activity statuses, and BMIs were encouraged to join.
A one-arm, pre-test, post-test study design was utilized. We examined whether the hydration status of participants in the intervention improved or worsened during the course of the intervention, and then attributed any such improvement or deterioration to the intervention. Urine collections from an afternoon sample were gathered before and after the one-week intervention. For the intervention, the participating offices received a water dispensing system in close proximity to employee desk spaces. A reusable water bottle was also given to each participant. Urine specific gravity (USG) was assessed in all urine samples to indicate hydration status, and all participants completed water intake surveys before and after the intervention.
From this study, the overall change in water intake over the course of the one-week intervention was 143 ounces/day. This is an average of adding two and a half 8 oz glasses of water each day of the week per participant. USG also decreased significantly at the end of the intervention in comparison to the baseline value. In the greater body of research, this study strengthens the viability of inputting a hydration station and offering reusable water bottles to employees. This cost-effective method is an easy way to incorporate employee wellness in the workplace. The benefit of employees to drink more water is numerous, including increased focus, mental reactivity, and overall mood and wellness.
Participants were employees working full-time jobs with Arizona State University or Tri Star Motor Company. Employees had to be 18 or older were invited to join the study. Employees participating in the study lived within the the greater Phoenix area. Participants of all races, genders, activity statuses, and BMIs were encouraged to join.
A one-arm, pre-test, post-test study design was utilized. We examined whether the hydration status of participants in the intervention improved or worsened during the course of the intervention, and then attributed any such improvement or deterioration to the intervention. Urine collections from an afternoon sample were gathered before and after the one-week intervention. For the intervention, the participating offices received a water dispensing system in close proximity to employee desk spaces. A reusable water bottle was also given to each participant. Urine specific gravity (USG) was assessed in all urine samples to indicate hydration status, and all participants completed water intake surveys before and after the intervention.
From this study, the overall change in water intake over the course of the one-week intervention was 143 ounces/day. This is an average of adding two and a half 8 oz glasses of water each day of the week per participant. USG also decreased significantly at the end of the intervention in comparison to the baseline value. In the greater body of research, this study strengthens the viability of inputting a hydration station and offering reusable water bottles to employees. This cost-effective method is an easy way to incorporate employee wellness in the workplace. The benefit of employees to drink more water is numerous, including increased focus, mental reactivity, and overall mood and wellness.
ContributorsWildermuth, Kelsi (Author) / Johnston, Carol (Thesis advisor) / Dixon, Kathleen (Committee member) / Levinson, Simin (Committee member) / Arizona State University (Publisher)
Created2018
Description
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
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
It is widely documented and accepted that athletes have difficulty maintaining adequate hydration status and that dehydration is a key risk factor for the heat-related illnesses commonly observed among athletes. Research has also suggested that hydration status can influence cognitive performance. Educational interventions focused on rehydration strategies have had minimal success reducing dehydration rates; hence, alternative interventions promoting adequate hydration status in athletes should be explored. This trial examined the efficacy of a commercial hydration mobile application (app) for reducing dehydration rates in campus athletes. Fifty-eight college students aged 18-40 y, who participated in club-level collegiate athletics were recruited from a large Southwestern university and randomized by team to one of two study arms, the Standard of Care – Education (EDU) or the hydration mobile app (APP), to determine if app technology improved hydration status as compared to traditional education messaging. Twenty-three (79%) in the EDU group and twenty (69%) in the APP group were mildly-dehydrated at baseline based on the three-day averages of hydration assessment (USG 1.010). Moreover, 31% (n=9) and 28% (n=8) of the EDU and APP groups, respectively, were dehydrated (USG 1.020). No significant differences were found between the EDU and APP groups following the intervention. Three-day average post-intervention USG testing showed 76% (n=22) and 72% (n=21) of the EDU and APP groups respectively were at best mildly-dehydrated. Additionally, 28% (n=8) and 17% (n=5) were considered dehydrated. Neither intervention improved hydration status after four weeks of treatment. Further analyses of cognitive measures were conducted by hydration assessment groups at baseline and post-intervention: hydrated (HYD) (USG < 1.020) or dehydrated (DEH) (USG 1.020). No significant differences between hydration status were found between intervention groups. Additionally, no significant improvements were seen for either group, which indicates there is still a need for a novel way to improve hydration status in this population. Multi-dimensional interventions and individualized interventions to improve hydration status in this at-risk population may be more effective. Additional research should be conducted to determine if there is any cognitive performance enhancement associated with dehydration or mild-dehydration by reassessing previous data and conducting future trials.
ContributorsZemek, Kate A (Author) / Johnston, Carol (Thesis advisor) / Hekler, Eric (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Ransdell, Lynda (Committee member) / Swan, Pamela (Committee member) / Arizona State University (Publisher)
Created2017
Description
Water is an essential nutrient that is often overlooked. As a result of this hydration status is often forgotten as well. Becoming hypohydrated puts athletes at risk of decreased performance and potentially life-threatening heat illness. Being able to self-assess hydration status is may be instrumental in helping athletes safely optimize performance. Therefore, this study investigated, 1) the ability of an athletic population vs. trained investigators to self-diagnose underhydration, 2) the diagnostic ability of urine color (Ucol) charts as a method for diagnosing underhydration, and 3) the accuracy of participant and investigator assessments. Members of an athletic population each provided a urine sample and scored samples using both the traditional 8-color and newly developed 7-color Ucol chart. Investigators then scored the samples using the same methods. To determine the diagnostic value of the Ucol charts, Ucol scores were compared to concentration measures of Urine Specific Gravity (USG) and Urine Osmolality (Uosm). Differences in participant and investigator scores were compared using Mann-Whitney U and Spearman’s Correlation. Bland-Altman plots were drawn to assess individual differences in reporting against the mean of the two methods. Receiver Operating Characteristic (ROC) analysis was used to both determine the ability of both charts to diagnose underhydration and to determine how well participants and investigators can determine their level of hydration. Athletes reported Ucol significantly lighter compared to investigators. Investigators showed no difference in reporting between the two charts but, athletes reported less than a color shade difference. The charts performed fair (8-color) to good (7-color) at diagnosing hypohydration. Athletes reported with less accuracy compared to investigators, and Ucol classification was found to be more accurate when compared to USG. Ucol charts are a practical tool to determine hydration status. Ucol scoring is similar regardless of the type of chart used. Trained investigators reported with slightly higher accuracy on both charts compared to untrained athletes. Athletes score Ucol fair to good in comparison to investigators. Ucol scoring is similar regardless of the type of chart used. The diagnostic ability of both Ucol charts is good in relation to USG. With education, athletes may be able to improve scores.
ContributorsPesek, Kathryn Margaret (Author) / Wardenaar, Floris (Thesis advisor) / Johnston, Carol (Committee member) / Yudell, Amber (Committee member) / Arizona State University (Publisher)
Created2022
Description
Plant-based eaters are known to reap nutritional benefits due to their dietchoice, but it is important to evaluate dietary differences that may put them at a disadvantage compared to omnivores. Stark differences exist in daily intakes of protein between vegans and omnivores, which may lead to several risks including decreased strength and bone density. The purpose of this study was to analyze the differences in protein intake, lean mass, strength, and bone density in vegans versus omnivores in order to support the argument for an increased recommended daily allowance (RDA) for protein for plant-based eaters. Participants in this study were assigned to groups based on omnivorous (n = 25) or vegan (n = 19) dietary pattern. Nineteen matched pairs were created based on age and BMI. Data was collected at a single lab visit and included health history and physical activity readiness questionnaires, 24-hr food recall, and anthropometric measures. Bone mineral density (BMD) was measured using DEXA and strength was assessed using hand and Biodex dynamometers. Statistical analyses were conducted using independent samples t-tests and Pearson’s correlation tests to evaluate differences in body composition, bone density, strength, and dietary intake between the two groups with significance set at p.05. Differences were seen in daily calorie (p=.007), protein (p<.001), fat (p<.001), and fiber (p=.009) intake. Lean mass (p=.282) and bone density (p=.651) were not different between groups, but lower body strength was different (p=.008). There was a correlation between lower body strength and protein intake (p<.001), and lean mass was correlated with lower body strength (p<.001), grip strength (p<.001), and bone density (p<.001), but not
i
LBM (p=0.158). Correlations were also observed between BMD and lower body strength (p=.004). These data suggest that there is a significant difference between protein intake in vegans versus omnivores, which appears to have a positive association with strength. BMD also has a positive association with strength as well as lean mass. Cumulatively, the results suggest that it may be beneficial for vegans to increase daily protein intake.
ContributorsNadalet, Camila R (Author) / Johnston, Carol (Thesis advisor) / Shepard, Christina (Committee member) / Hooshmand, Shirin (Committee member) / Arizona State University (Publisher)
Created2023
Description
Background: Vegan and vegetarian diets have gained in popularity in recent years. Stated reasons for this include some possible health benefits and concerns of animal welfare. Though considered to be nutritionally adequate, questions remain over whether current protein recommendations of 0.8 g/kg/d are sufficient to maintain body processes and growth. Protein is unique in that it is the only macronutrient that contains nitrogen. Its status can be determined through nitrogen balance analysis of the urine if protein content of the diet is known. Nitrogen balance is considered the gold standard for determining protein intake requirements. A negative balance indicates a catabolic state, whereas a positive nitrogen balance is seen during anabolism. In healthy people, nitrogen equilibrium is desired under normal circumstances. This equilibrium reflects the net synthesis and breakdown of proteins. While nitrogen balance techniques have been used for decades, currently, there are no known studies measuring nitrogen balance and protein intake in strict vegans. Methods: Twenty vegan, inactive, male participants were recruited and received a 5-day eucaloric diet with a known protein content held constant at 0.8 g/kg/d. On day five, 24-hour urine was collected by participants and aliquoted for future analysis. Nitrogen content of the urine was determined through photometric assay and compared to the known nitrogen content of the diet to calculate nitrogen balance status.
Results: Mean absolute nitrogen balance (-1.38 ± 1.22 g/d, effect size = -1.13) was significantly lower than zero (equilibrium) (p < .001). Mean relative nitrogen balance (-18.60 ± 16.96 mg/kg/d, effect size = -1.10) was significantly lower than zero (p < .001). There were no correlations seen between nitrogen balance and age, years as vegan, or fat- free mass.
Conclusion: Consuming 0.8 g/kg/d of protein is insufficient to produce nitrogen balance in long-term vegans.
ContributorsBartholomae, Eric (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Wharton, Christopher (Committee member) / Lee, Chong (Committee member) / Kressler, Jochen (Committee member) / Arizona State University (Publisher)
Created2022