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- All Subjects: Nutrition
- Creators: Shepard, Christina
- Member of: ASU Electronic Theses and Dissertations
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
Background. Research suggests that non-O blood types are at an increased risk of thrombosis and related health complications in cardiovascular disease (CVD). This is due in part to higher concentrations of von Willebrand factor (VWF), an important factor involved in blood clotting. Objective. The purpose of this study was to examine the effects of a vegetarian-like diet on blood coagulation and other health parameters in adults with type A blood compared to type O blood over a four week intervention. Given the lack of previous research on blood type and diet, it was hypothesized that no difference in blood coagulation would be observed. Design. This study was a randomized, parallel arm, dietary intervention using healthy, omnivorous adults with blood types A and O. A total of 39 subjects completed the study. Subjects were randomized into two groups: a vegetarian-like diet group made up of 12 type As and 12 type Os and an omnivorous control diet group made up of 11 type As and 12 type Os. At weeks 0 and 4, fasting blood was drawn and analyzed for prothrombin time (PT), activated partial thromboplastin time (APTT), von Willebrand factor (VWF), total cholesterol, LDL, HDL, triglycerides, and CRP. In addition, subjects were weighed and filled out a FFQ at weeks 0 and 4. Results. After adhering to a vegetarian-like diet for four weeks, type Os had a significant increase in PT (+0.24±0.32 sec/ p=0.050), whereas type As saw no significant change. There was a trend of weight loss for type Os in the vegetarian-like diet group (-1.8±2.6 lb/ p=0.092) and significant weight loss for type As (-0.9±2.1 lb/ p=0.037). Both blood types O and A experienced significant decreases in BMI (-0.3±0.4/ p=0.092 and -0.2±0.3/ p=0.037, respectively). No change was seen in APTT, VWF, total cholesterol, LDL, HDL, triglycerides, or CRP. Conclusion. Type Os saw an increase in PT, perhaps indicating a reduction in risk of thrombosis and its related health complications. Type As were less responsive to the dietary intervention and may require more rigid dietary guidelines or a longer time on such a diet to see the benefits.
ContributorsBrown, Jennifer (Author) / Johnston, Carol (Thesis advisor) / Martin, Keith (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2013
Description
Background: Obesity is considered one of the most serious public health issues worldwide. Small, feasible lifestyle changes are necessary to obtain and maintain weight loss. Clinical evidence is inconclusive about whether meal preloading is an example of a small change that could potentially increase the likelihood of weight loss and weight maintenance. Objective: The aim of this study is to determine if consuming 23 grams of peanuts, as a meal preload, before a carbohydrate-rich meal will lower post prandial glycemia and insulinemia and increase satiety in the 2 hour period after a carbohydrate-rich meal. Design: 15 healthy, non-diabetic adults without any known peanut or tree nut allergies were recruited from a campus community. A randomized, 3x3 block crossover design was used. The day prior to testing participants refrained from vigorous activity and consumed a standard dinner meal followed by a 10 hour fast. Participants reported to the test site in the fasted state to complete one of three treatment meals: control (CON), peanut (NUT), or grain bar (BAR) followed one hour later by a carbohydrate-rich meal. Satiety, glucose and insulin were measured at different time points throughout the visit. Each participant had a one-week washout period between visits. Results: Glucose curves varied between treatments (p=.023). Blood glucose was significantly higher one hour after ingestion of the grain bar compared to the peanut and control treatments (p<.001). At 30 minutes after the meal, the control glucose was significantly higher than for the peanut or grain bar (p=.048). Insulin did vary significantly between treatments (p<.001). The insulin change one hour after grain bar consumption was significantly higher than after the peanut or control at the same time point (p<.001). The change in insulin one hour after peanut consumption was significantly higher than for the control treatment (p=.002). Overall satiety, expressed as the 180 minute AUC, differed significantly between treatments (p=.001). One hour after preload consumption, peanut and bar consumption was associated with greater satiety than the water control (p<.001). At 30 minutes post-meal, the grain bar was associated with greater satiety versus the water control (p=.049). The bar was also associated with greater satiety versus peanut and control at 60 and 90 minutes post-meal (p=.003 and .034, respectively). At 120 minutes post-meal, the final satiety measurement, the bar was still associated with greater satiety than the peanut preload (p=.023). Total energy intake, including test meal, on treatment days did not differ significantly between treatment (p=.233). Conclusions: Overall satiety, blood glucose and blood insulin levels differed at different time points depending on treatment. Both meal preloads increased overall satiety. However, grain bar ingestion resulted in sustained satiety, greater than the peanut preload. Grain bar ingestion resulted in an immediate glycemic and insulinemic response. However, the response was not sustained after the test meal was ingested. The results of this study suggest that a low-energy, carbohydrate-rich meal preload may have a positive impact on weight maintenance and weight loss by initiating a sustained increase in overall satiety. More research is needed to confirm these findings.
ContributorsFleming, Katie R (Author) / Johnston, Carol (Thesis advisor) / Wharton, Christopher (Christopher Mack), 1977- (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2012
Description
ABSTRACT This randomized, controlled, double-blind crossover study examined the effects of a preprandial, 20g oral dose of apple cider vinegar (ACV) on colonic fermentation and glycemia in a normal population, with the ultimate intention of identifying the mechanisms by which vinegar has been shown to reduce postprandial glycemia and insulinemia. Fifteen male and female subjects were recruited, ages 20-60y, who had no prior history of gastrointestinal (GI) disease or resections impacting normal GI function, were non-smokers, were non-vegetarian/vegan, were not taking any medications known to alter (glucose) metabolism, and were free of chronic disease including diabetes. Subjects were instructed to avoid exercise, alcohol and smoking the day prior to their trials and to consume a standardized, high-carbohydrate dinner meal the eve prior. There was a one-week washout period per subject between appointments. Breath hydrogen, serum insulin and capillary glucose were assessed over 3 hours after a high-starch breakfast meal to evaluate the impact of preprandial supplementation with ACV or placebo (water). Findings confirmed the antiglycemic effects of ACV as documented in previous studies, with significantly lower mean blood glucose concentrations observed during ACV treatment compared to the placebo at 30 min (p=0.003) and 60 min (p=0.005), and significantly higher mean blood glucose concentrations at 180 min (p=0.045) postprandial. No significant differences in insulin concentrations between treatments. No significant differences were found between treatments (p>0.05) for breath hydrogen; however, a trend was observed between the treatments at 180 min postprandial where breath hydrogen concentration was visually perceived as being higher with ACV treatment compared to the placebo. Therefore, this study failed to support the hypothesis that preprandial ACV ingestion produces a higher rate of colonic fermentation within a 3 hour time period following a high-carbohydrate meal. Due to variations in experiment duration noted in other literature, an additional study of similar nature with an expanded specimen collections period, well beyond 3 hours, is warranted.
ContributorsMedved, Emily M (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2012
Description
Background: Adequate consumption of fruit and vegetables has been shown to prevent chronic diseases, such as cardiovascular disease, high blood pressure, and type two diabetes. The majority of Americans still consume inadequate daily servings of fruit and vegetables, which include women. Inadequate consumption of fruit and vegetables can be contributed to multiple barriers that hinder consumption in both urban and non-urban areas. The Special Supplemental Nutrition Program for Women, Infant, and Children (WIC) has been shown to positively influence fruit and vegetable consumption by providing healthy foods, such as fruit and vegetables. This study aims to compare the fruit and vegetable consumption of WIC and non-WIC participants between urban and non-urban Rural-Urban Commuting Area (RUCA) codes. Methods: This study was a cross-sectional, secondary analysis of a single time point from the Snuggle Bug/Acurrucadito Study, which had a sample size of (n=53) participants. The participants were separated into two groups, WIC participants, and non-WIC participants, and then further divided based on their respected RUCA code for comparison purposes. The assessment of fruit and vegetable consumption assessment derived from the participant’s 3-day food record. Results: The average consumption of fruit and vegetable consumption among participants was 3.8±2.5 servings There was an inverse relationship between WIC participation and fruit and vegetable consumption among all categories (fruit no juice -0.79, vegetables -0.32, vegetables no potato -0.32, fruit no juice and vegetables -1.1, and fruit no juice and vegetables no potato -1.1). However, none of the results were considered statistically significant. In addition, our study was unable to identify an association between fruit and vegetable consumption and locale due to the small sample size. Conclusions: There was no link observed between fruit and vegetable consumption and WIC participation. Further research of high quality is needed to confirm the relationship between fruit and vegetable consumption of WIC and non-WIC participants in urban and non-urban populations.
ContributorsOrtiz, Steven Michael (Author) / Bruening, Meg (Thesis advisor) / Whisner, Corrie (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2022
Description
Objective: This research examined the impact of daily ingestions of commercial high protein nutrition bars (with or without added fiber) on 24-h energy intake and satiety
for one week among free-living young healthy adults.
Design: In a 4-week double-blind, randomized crossover trial, 21 normal and
overweight participants (Mean BMI 23.9 ± 2.7 kg/m²), free of chronic diseases, were
randomized assigned to HP (high protein: 21 g protein) or HPHF (high protein high fiber:
20g, 14 g fiber) nutrition bars. Participants were included in the trial if they meet the
criteria for non-smoking, and not taking prescribed medication for chronic diseases.
Participants were instructed to consume commercial nutrition bars daily for seven
consecutive days. Body composition was measured with a bioelectrical impedance scale
at weeks 1, 3, and 5. Dietary data was recorded by the MyFitnessPal app on Wednesday,
Friday, and Sunday of each week.
Results: The mean energy intake for the weeks HPHF bars were consumed is
significantly higher compared to baseline (1998 ± 534 vs. 1806 ± 537 respectively; p =
0.035). The mean fat mass following one week of HPHF bar consumption was
significantly higher than the baseline value (18.8 ± 6.8 vs. 18.3 ± 6.7 respectively; p =
0.023) and trended higher (18.8 ± 6.8 vs. 18.3 ± 6.7 respectively; p = 0.057) in
comparison to the value following one week of HP bar consumption. For the high
physical activity level group (n = 10), the mean energy intakes for the baseline week and
the weeks the HP and HPHF bars were consumed were 1883 ± 597 kcal, 2154 ± 712 kcal,
and 2099 ± 603 kcal respectively (p ˂ 0.04; energy intakes for both bars were
significantly different from baseline). Nutrient intakes differed significantly mirroring the
nutrient profile for each specific bar. There are significant effects after both bars on
satiety, but there were no differences between each bar.
Conclusions: Sales of nutrition bars gained rapid growth and may represent a
unique source for specific nutrients. However, ingestion of commercial high protein
nutrition bars may increase the risk of gaining fat mass and eventual body mass over
time.
ContributorsPang, Minghan (Author) / Johnston, Carol (Thesis advisor) / Shepard, Christina (Committee member) / Alexon, Christy (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
Low water intake and underhydration are public health issues that may increase risk for diseases such as Type 2 Diabetes Mellitus. Studies suggest that high vasopressin (AVP) levels associated with low water intake may contribute to hyperglycemia. This study explored the physiological system by which AVP impairs glucose regulation through a single-blind randomized, counterbalanced, crossover design. This is a pilot and feasibility study of AVP infusion at increasing incremental rates, which was completed to determine the rate of infusion for the cross-over study. Participants completed a control and experimental trial. The experimental trial included a 3-hour AVP infusion and a 2-hour euglycemic-hyper insulinemic clamp at the end of the first hour versus control of 0.9% sodium chloride replacing AVP. In both trials, blood samples were taken every 5 minutes to measure glucose, as well as 7 other time points of insulin infusion. Two participants completed the pilot (47.5±3.5 years, 172.5 ±7.5cm, 82.5±17.7kg, 27.5±3.5 kg/m2, 5.1±0.64% HbA1c), and 3 participants completed the cross-over study (49±1.7 years, 173.7±6.7cm, 80.4±150kg, 26.5±3.2kg/m2, 5.3±0.2% HbA1c), all females. The rate of AVP infusion for the cross-over study was 12.5 mU/min. Compared to the control, the AVP trial blood glucose trended higher towards the end of the experiment, as did glucose metabolism, plasma osmolality, and plasma volume. Blood pressure was slightly higher in the AVP trial versus the saline, while plasma sodium and potassium levels did not differ. Total plasma protein seemed higher in the saline trials than in the AVP trials. This study supports the notion that increased levels of vasopressin over time may increase blood glucose. This could lead to supplementation of type 2 diabetes interventions with increased water intake.
ContributorsAcri, Emily Suzanne (Author) / Kavouras, Stavros (Thesis advisor) / Johnston, Carol (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2024
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 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
Description
Nutrition instruction has become more accessible; it is no longer relegated to the doctor’s office, dietitian briefing, outpatient clinic, or hospital. Now it is available in people’s hands, pockets, and purses via their smartphone. Since nutrition instruction has become more accessible, health professionals and members of the general public are increasingly interested in using smartphone apps to assist with health-related dietary changes. With more and more of the population required to follow certain dietary recommendations and/or monitor specific nutrient intake, commercially available apps may be a useful and cost-effective resource for the public. The purpose of this four-week intervention was to determine if the popular calorie counter app, MyFitnessPal, can be used to reduce sodium intake to ≤ 2,300 mg/day compared to the traditional paper-and-pencil method. This four-week randomized parallel trial enrolled 30 generally healthy adults who were 18 to 80 years of age. Participants were randomly assigned to the MyFitnessPal (“APP”) group or to the paper (“PAP”) group and required to meet three times with the researcher for screening, baseline (start), and completion of the study. There was a significant difference in the mean urinary sodium change between the APP group and the PAP group from the start of the intervention to the completion (-24.0±32.6 and 8.5±41.9 mmol/g creatinine respectively, p = 0.027). Other positive trends that resulted from the intervention included a decline in dietary sodium in both groups and a higher adherence in the APP group compared to the PAP group regarding recording method. The MyFitnessPal app proved to be a useful tool in reducing and/or monitoring sodium intake. Thus, this trial reinforces the potential of this app to be used for monitoring other nutrients, but further research needs to be conducted.
ContributorsIpjian, Michelle (Author) / Johnston, Carol (Thesis advisor) / Shepard, Christina (Committee member) / Johnson, Melinda (Committee member) / Arizona State University (Publisher)
Created2016