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Description
The body is capable of regulating hunger in several ways. Some of these hunger regulation methods are innate, such as genetics, and some, such as the responses to stress and to the smell of food, are innate but can be affected by body conditions such as BMI and physical activity.

The body is capable of regulating hunger in several ways. Some of these hunger regulation methods are innate, such as genetics, and some, such as the responses to stress and to the smell of food, are innate but can be affected by body conditions such as BMI and physical activity. Further, some hunger regulation methods stem from learned behaviors originating from cultural pressures or parenting styles. These latter regulation methods for hunger can be grouped into the categories: emotion, environment, and physical. The factors that regulate hunger can also influence the incidence of disordered eating, such as eating in the absence of hunger (EAH). Eating in the absence of hunger can occur in one of two scenarios, continuous EAH or beginning EAH. College students are at a particularly high risk for EAH and weight gain due to stress, social pressures, and the constant availability of energy dense and nutrient poor food options. The purpose of this study is to validate a modified EAH-C survey in college students and to discover which of the three latent factors (emotion, environment, physical) best predicts continual and beginning EAH. To do so, a modified EAH-C survey, with additional demographic components, was administered to students at a major southwest university. This survey contained two questions, one each for continuing and beginning EAH, regarding 14 factors related to emotional, physical, or environmental reasons that may trigger EAH. The results from this study revealed that the continual and beginning EAH surveys displayed good internal consistency reliability. We found that for beginning and continuing EAH, although emotion is the strongest predictor of EAH, all three latent factors are significant predictors of EAH. In addition, we found that environmental factors had the greatest influence on an individual's likelihood to continue to eat in the absence of hunger. Due to statistical abnormalities and differing numbers of factors in each category, we were unable to determine which of the three factors exerted the greatest influence on an individual's likelihood to begin eating in the absence of hunger. These results can be utilized to develop educational tools aimed at reducing EAH in college students, and ultimately reducing the likelihood for unhealthy weight gain and health complications related to obesity.
ContributorsGoett, Taylor (Author) / Johnston, Carol (Thesis advisor) / Lee, Chong (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2013
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Description
The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested

The unpleasant bitter taste found in many nutritious vegetables may deter people from consuming a healthy diet. We investigated individual differences in taste perception and whether these differences influence the effectiveness of bitterness masking. To test whether phenylthiocarbamide (PTC) `supertasters' also taste salt and sugar with greater intensity, as suggested by Bartoshuk and colleagues (2004), we infused strips of paper with salt water or sugar water. The bitterness rating of the PTC strip had a significant positive linear relationship with ratings of both the intensity of sweet and salt, but the effect sizes were very low, suggesting that the PTC strip does not give a complete picture of tasting ability. Next we investigated whether various seasonings could mask the bitter taste of vegetables and whether this varied with tasting ability. We found that sugar decreased bitterness and lemon decreased liking for vegetables of varying degrees of bitterness. The results did not differ by ability to taste any of the flavors. Therefore, even though there are remarkable individual differences in taste perception, sugar can be used to improve the initial palatability of vegetables and increase their acceptance and consumption.
ContributorsWilkie, Lynn Melissa (Author) / Phillips, Elizabeth D. (Thesis advisor) / Cohen, Adam (Committee member) / Johnston, Carol (Committee member) / Arizona State University (Publisher)
Created2012
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Description
College students are a niche of young adults, characterized by abnormal sleeping habits and inactive lifestyles. Many students entering college are as young as 18 years old and graduate by 22 years old, a window of time in which their bones are still accruing mineral. The purpose of this cross-sectional

College students are a niche of young adults, characterized by abnormal sleeping habits and inactive lifestyles. Many students entering college are as young as 18 years old and graduate by 22 years old, a window of time in which their bones are still accruing mineral. The purpose of this cross-sectional study was to determine whether sleep patterns and physical activity observed in college students (N= 52) 18-25 years old at Arizona State University influenced bone biomarkers, osteocalcin (OC) and N-terminal telopeptide of type 1 collagen (NTX-1) concentrations. Students completed various dietary and health history questionnaires including the International Physical Activity Questionnaire short form. Students wore an actigraphy watch for 7 consecutive nights to record sleep events including total sleep time, sleep onset latency and wake after sleep onset. Total sleep time had a significant, negative correlation with OC (r = -0.298, p-value =0.036) while sleep onset latency had a significant, positive correlation with NTX-1 serum concentration (r = 0.293, p-value = 0.037). Despite correlational findings, only sleep percent was found to be significant (beta coefficient = 0.271 p-value = 0.788) among all the sleep components assessed, after adjusting for gender, race, BMI and calcium intake in multivariate regression models. Physical activity alone was not associated with either bone biomarker. Physical activity*sleep onset latency interactions were significantly correlated with osteocalcin (r = 0.308, p-value =0.006) and NTX-1 (r = 0.286, p-value = 0.042) serum concentrations. Sleep percent*physical activity interactions were significantly correlated with osteocalcin (r = 0.280, p-value = 0.049) but not with NTX-1 serum concentrations. Interaction effects were no longer significant after adjusting for covariates in the regression models. While sleep percent was a significant component in the regression model for NTX-1, it was not clinically significant. Overall, sleep patterns and physical activity did not explain OC and NTX-1 serum concentrations in college students 18-25 years old. Future studies may need to consider objective physical activity devices including accelerometers to measure activity levels. At this time, college students should review sleep and physical activity recommendations to ensure optimal healthy habits are practiced.
ContributorsMahmood, Tara Nabil (Author) / Whisner, Corrie (Thesis advisor) / Dickinson, Jared (Committee member) / Petrov, Megan (Committee member) / Adams, Marc (Committee member) / Arizona State University (Publisher)
Created2019
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Description
The effects of iron and chromium blood concentrations have been linked to blood glucose control in diabetics. It is suggested that iron causes oxidative stress in the beta cells of the pancreas and adipocytes creating insulin insufficiency and resistance. Chromium is believed to increase the action of insulin

The effects of iron and chromium blood concentrations have been linked to blood glucose control in diabetics. It is suggested that iron causes oxidative stress in the beta cells of the pancreas and adipocytes creating insulin insufficiency and resistance. Chromium is believed to increase the action of insulin through its biologically active molecule chromodulin. Both of these mechanisms are not clear. This 20 week case study tests the feasibility of combining iron depletion therapy followed by chromium supplementation to improve insulin sensitivity. This single case study followed a protocol of two blood donations separated by eight weeks followed by chromium supplementation of 250 µg of chromium picolinate once a day four weeks after the second blood donation. Fasting blood draws were taken at baseline, post blood draws and pre and post chromium supplementation. Results were not promising for the first hypothesis of lowering HbA1c, but the results were promising for the second hypothesis of improving insulin sensitivity by lowering the HOMA score.
ContributorsJarrett, Nia (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2015
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Description
Objectives

This cross-sectional study sought to assess the eating and physical activity behaviors among in-state and out-of-state college freshmen attending Arizona State University and to determine if social connectedness mediated the relationship between residency status and eating and physical activity behaviors.

Methods

College freshmen from two dormitories were recruited for participation from Arizona

Objectives

This cross-sectional study sought to assess the eating and physical activity behaviors among in-state and out-of-state college freshmen attending Arizona State University and to determine if social connectedness mediated the relationship between residency status and eating and physical activity behaviors.

Methods

College freshmen from two dormitories were recruited for participation from Arizona State University’s Tempe campus. A 128-item survey assessing demographics, college life, eating and physical activity behaviors, and social connectedness was administered. In addition, participants completed up to three days of dietary recall. Multivariate linear regression models, adjusting for age, gender, race, ethnicity, highest parental education, dormitory, Pell grant status, number of dietary recalls, and availability of a weekend day of dietary recall were used to assess the relationships between residency status, social connectedness, and eating and physical activity behaviors.

Results

No associations were observed between residency status and calories, grams and percentage of calories from fat, and added sugar. There was a statistically significant association between residency status and moderate-to-vigorous physical activity (MVPA). In-state students reported 21 minutes less per day of MVPA than out-of-state students did (β=-20.85; 95% CI=-30.68, -11.02; p<0.001). There was no relationship between residency status and social connectedness. Social connectedness and eating and physical activity behaviors were not associated. Social connectedness did not mediate the relationship between residency status and eating and physical activity behaviors.

Conclusions

In-state and out-of-state students differed in their MVPA; however, this relationship was not mediated by social connectedness. Further studies are needed to confirm the relationship between MVPA and residency status. In addition, more studies are needed to assess the relationship between social connectedness and MVPA.
ContributorsNelson, Stephanie A. (Stephanie Anne), 1958- (Author) / Bruening, Meg (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Whisner, Corrie (Committee member) / Arizona State University (Publisher)
Created2016
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Description
College weight gain and obesity are significant problems impacting our society, leading to a considerable number of comorbidities during and after college. Gut microbiota are increasingly recognized for their role in obesity and weight gain. Currently, research exploring the gut microbiome and its associations with dietary intake and

College weight gain and obesity are significant problems impacting our society, leading to a considerable number of comorbidities during and after college. Gut microbiota are increasingly recognized for their role in obesity and weight gain. Currently, research exploring the gut microbiome and its associations with dietary intake and body mass index (BMI) is limited among this population. Therefore, the purpose of this study was to assess associations between the gut microbiome, BMI, and dietary intake in a population of healthy college students living in two dorms at Arizona State University (n=90). Cross-sectional analyses were undertaken including 24-hour dietary recalls and anthropometrics (height, weight and BMI). High throughput Bacterial 16S rRNA gene sequencing of fecal samples was performed to quantify the gut microbiome and analyses were performed at phyla and family levels. Within this population, the mean BMI was 24.4 ± 5.3 kg/m2 and mean caloric intake was 1684 ± 947 kcals/day. Bacterial community analysis revealed that there were four predominant phyla and 12 predominant families accounting for 99.3% and 97.1% of overall microbial communities, respectively. Results of this study suggested that a significant association occurred between one principal component (impacted most by 22 microbial genera primarily within Firmicutes) and BMI (R2=0.053, p=0.0301). No significant correlations or group differences were observed when assessing the Firmicutes/Bacteroidetes ratio in relation to BMI or habitual dietary intake. These results provide a basis for gut microbiome research in college populations. Although, findings suggest that groups of microbial genera may be most influential in obesity, further longitudinal research is necessary to more accurately describe these associations over me. Findings from future research may be used to develop interventions to shift the gut microbiome to help moderate or prevent excess weight gain during this important life stage.
ContributorsHotz, Ricci-Lee (Author) / Whisner, Corrie (Thesis advisor) / Bruening, Meredith (Committee member) / Vega-Lopez, Sonia (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2016
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Description
ABSTRACT The hormone leptin is an important regulator of body weight and energy balance, while nitric oxide (NO) produced in the blood vessels is beneficial for preventing disease-induced impaired vasodilation and hypertension. Elevations in the free radical superoxide can result in impaired vasodilation through scavenging of NO. Omega 3 is

ABSTRACT The hormone leptin is an important regulator of body weight and energy balance, while nitric oxide (NO) produced in the blood vessels is beneficial for preventing disease-induced impaired vasodilation and hypertension. Elevations in the free radical superoxide can result in impaired vasodilation through scavenging of NO. Omega 3 is a polyunsaturated fatty acid that is beneficial at reducing body weight and in lowering many cardiovascular risk factors like atherosclerosis. The present study was designed to examine the change in plasma concentrations of leptin, nitric oxide, and the antioxidant superoxide dismutase in addition to examining the association between leptin and NO in healthy normal weight adult female subjects before and following omega 3 intakes. Participants were randomly assigned to either a fish oil group (600 mg per day) or a control group (1000 mg of coconut oil per day) for 8 weeks. Results showed no significant difference in the percent change of leptin over the 8 week supplementation period for either group (15.3±31.9 for fish oil group, 7.83±27 for control group; p=0.763). The percent change in NO was similarly not significantly altered in either group (-1.97±22 decline in fish oil group, 11.8±53.9 in control group; p=0.960). Likewise, the percent change in superoxide dismutase for each group was not significant following 8 weeks of supplementation (fish oil group: 11.94±20.94; control group: 11.8±53.9; p=0.362). The Pearson correlation co-efficient comparing the percent change of both leptin and NO was r2= -0.251 demonstrating a mildly negative, albeit insignificant, relationship between these factors. Together, these findings suggest that daily supplementation with 600 mg omega 3 in healthy females is not beneficial for improving these cardiovascular risk markers. Future studies in this area should include male subjects as well as overweight subjects with larger doses of fish oil that are equivalent to three or more servings per week. The importance of gender cannot be underestimated since estrogen has protective effects in the vasculature of females that may have masked any further protective effects of the fish oil. In addition, overweight individuals are often leptin-resistant and develop impaired vasodilation resulting from superoxide-mediated scavenging of nitric oxide. Therefore, the reported antioxidant and weight loss properties of omega 3 supplementation may greatly benefit overweight individuals.
ContributorsAlanbagy, Samer (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Shepard, Christina (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2014
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Description
There are limited studies exploring the direct relationship between coconut oil and cholesterol concentrations. Research in animals and a few intervention trials suggest that coconut oil increases the good cholesterol (high density lipoprotein, HDL) and thus reduces the risk of cardiovascular disease. Preliminary research at Arizona State University (ASU) has

There are limited studies exploring the direct relationship between coconut oil and cholesterol concentrations. Research in animals and a few intervention trials suggest that coconut oil increases the good cholesterol (high density lipoprotein, HDL) and thus reduces the risk of cardiovascular disease. Preliminary research at Arizona State University (ASU) has found similar results using coconut oil as a placebo, positive changes in HDL cholesterol concentrations were observed.

The goal of this randomized, double blind, parallel two arm study, was to further examine the beneficial effects of a 2g supplement of coconut oil taken each day for 8 weeks on cholesterol concentrations, specifically the total cholesterol to HDL cholesterol ratio, compared to placebo.

Forty-two healthy adults between 18-40 years of age, exercising less than 150 minutes each week, non smoking, BMI between 22-35 and not taking any medications that could effect blood lipids were recruited from the ListServs at ASU. Participants were randomized to receive either a placebo capsule of flour or a coconut oil capsule (Puritan’s Pride brand, coconut oil softgels, 2g each) and instructed to take the capsules for 8 weeks.

Results indicated no significant change in total cholesterol to HDL ratio between baseline and 8 weeks in the coconut oil and placebo groups (p=0.369), no significant change in HDL (p=0.648), no change in LDL (p=0.247), no change in total cholesterol (p=0.216), and no change in triglycerides (p=0.369).

Blood lipid concentrations were not significantly altered by a 2g/day dosage of coconut oil over the course of 8 weeks in healthy adults, and specifically the total cholesterol to HDL ratio did not change or improve.
ContributorsShedden, Rachel (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2017
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Description
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
Obesity is highly prevalence in United States. Obesity can be seen as a positive energy balance, especially a positive fat balance. This may be due in part to how the human body uses energy sources. When a person overconsumes a meal that contains high amounts of both carbohydrate and fat,

Obesity is highly prevalence in United States. Obesity can be seen as a positive energy balance, especially a positive fat balance. This may be due in part to how the human body uses energy sources. When a person overconsumes a meal that contains high amounts of both carbohydrate and fat, carbohydrate will stimulate its own oxidation and suppress fat oxidation. This can result in a positive fat balance, which could eventually lead to obesity. Also, it has been shown that after consuming a meal endothelial function is frequently impaired for several hours during the postprandial period. Long-term endothelial dysfunction is a major cause of different types of cardiovascular disease. Exercise has been shown to stimulate fat oxidation and, when performed the day before meal ingestion, precondition arteries by enhancing endothelial function in the basal state. However, the acute effect of exercise on postprandial period is unknown. The purpose of this study is to examine the effect of high intensity interval exercise (HIIE) on the substrate oxidation and endothelial function in the postprandial period after consumption of “meal” consisting of a sugar-sweetened beverage (SSB) and a candy bar (480 kcal; ~75% sugar). Five subjects (4 males, 1 female; age=25yr, BMI=25 kg/m2) completed two conditions in random order: 1) no exercise control; 2) high-intensity interval exercise on a cycle ergometer: alternating 1-min intervals at 90-95% HRmax separated by 1-min of active recovery at 50W, for a duration sufficient to expend ~480 kcal. Endothelial function was measured by flow-mediated dilation (FMD) at baseline, and at 1, 2 and 4 hours postprandial. Substrate oxidation was measured by indirect calorimetry during the entire first hour postprandial and then during the last 20 min of hours 2-5 postprandial. Absolute postprandial fat oxidation (g/5 hours) was higher in HIIE (exercise: 5.47 ± 9.97, control: -9.78 ± 3.80; p<0.011). Absolute postprandial carbohydrate oxidation (g/5 hours) was higher in control group (control: 27.79 ± 6.20, exercise: -1.48 ± 7.75; p<0.019). Therefore, these results show that HIIE results in greater fat oxidation during the postprandial period in comparison to a no-exercise control condition. For FMD, there was no significant difference between groups, and no group x time interaction. However, there was a significant time effect (p<0.046), with both groups demonstrating a reduction in FMD during the postprandial period. FMD in the control condition decreased from 12% to 7.5% during the first 2 hours postprandial, and from 11.4% to 7.3% in the HIIE condition. These results indicate that HIIE performed 1 hour prior to ingestion of a SSB and candy bar does not prevent postprandial endothelial dysfunction.
ContributorsLin, Chia Yu (Author) / Gaesser, Glenn (Thesis advisor) / Whisner, Corrie (Committee member) / Angadi, Siddhartha (Committee member) / Arizona State University (Publisher)
Created2020