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- All Subjects: Obesity
- Creators: Johnston, Carol
- Creators: School of Human Evolution and Social Change
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 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
Description
Nut consumption, specifically almonds, have been shown to help maintain weight and influence disease risk factors in adult populations. Limited studies have been conducted examining the effect of a small dose of almonds on energy intake and body weight. The objective of this study was to determine the influence of pre-meal almond consumption on energy intake and weight in overweight and obese adults. In this study included 21, overweight or obese, participants who were considered healthy or had a controlled disease state. This 8-week parallel arm study, participants were randomized to consume an isocaloric amount of almonds, (1 oz) serving, or two (2 oz) cheese stick serving, 30 minutes before the dinner meal, 5 times per week. Anthropometric measurements including weight, waist circumference, and body fat percentage were recorded at baseline, week 1, 4, and 8. Measurement of energy intake was self-reported for two consecutive days at week 1, 4 and 8 using the ASA24 automated dietary program. The energy intake after 8 weeks of almond consumption was not significantly different when compared to the control group (p=0.965). In addition, body weight was not significantly reduced after 8 weeks of the almond intervention (p=0.562). Other parameters measured in this 8-week trial did not differ between the intervention and the control group. These data presented are underpowered and therefore inconclusive on the effects that 1 oz of almonds, in the diet, 5 per week has on energy intake and bodyweight.
ContributorsMcBride, Lindsey (Author) / Johnston, Carol (Thesis advisor) / Swan, Pamela (Committee member) / Mayol-Kreiser, Sandra (Committee member) / Arizona State University (Publisher)
Created2011
Description
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
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
Description
Objectives: To investigate the potential of vinegar supplementation as a means for reducing visceral fat in healthy overweight and obese adults, and to evaluate its effects on fasting blood glucose and fasting insulin.
Subjects and Methods: Forty-five sedentary overweight and obese adult participants with a waist circumference greater than 32 inches for women and 37 inches for men were randomly assigned to one of two groups, the vinegar group (VIN, n=21) or the control group (CON, n=24), and instructed to consume either two tablespoons of liquid red wine vinegar (3.6g acetic acid) or a control pill (0.0225g acetic acid) twice daily at the beginning of a meal for 8 weeks. Participants were also instructed to maintain normal diet and physical activity levels. Anthropometric measures, dual-energy x-ray absorptiometry (DXA) scans, blood samples, and 24-hour dietary recalls were collected at baseline and at end of trial. A compliance calendar was provided for daily tracking of vinegar supplementation.
Results: Compliance to vinegar supplementation averaged 92.7 ±13.3% among the VIN group and 89.1 ±18.9% among the CON group. There were no statistically significant differences in anthropometric measurements between baseline and week 8: weight (P=0.694), BMI (P=0.879), and waist circumference (P=0.871). Similarly, DXA scan data did not show significant changes in visceral fat (P=0.339) or total fat (P=0.294) between baseline and week 8. The VIN group had significant reductions in fasting glucose (P=0.003), fasting insulin (P <0.001), and homeostatic model assessment of insulin resistance scores (P <0.001) after treatment.
Conclusions: These data do not support the findings from previous studies that indicated a link between vinegar supplementation and increased fat metabolism, specifically visceral fat reduction.
Subjects and Methods: Forty-five sedentary overweight and obese adult participants with a waist circumference greater than 32 inches for women and 37 inches for men were randomly assigned to one of two groups, the vinegar group (VIN, n=21) or the control group (CON, n=24), and instructed to consume either two tablespoons of liquid red wine vinegar (3.6g acetic acid) or a control pill (0.0225g acetic acid) twice daily at the beginning of a meal for 8 weeks. Participants were also instructed to maintain normal diet and physical activity levels. Anthropometric measures, dual-energy x-ray absorptiometry (DXA) scans, blood samples, and 24-hour dietary recalls were collected at baseline and at end of trial. A compliance calendar was provided for daily tracking of vinegar supplementation.
Results: Compliance to vinegar supplementation averaged 92.7 ±13.3% among the VIN group and 89.1 ±18.9% among the CON group. There were no statistically significant differences in anthropometric measurements between baseline and week 8: weight (P=0.694), BMI (P=0.879), and waist circumference (P=0.871). Similarly, DXA scan data did not show significant changes in visceral fat (P=0.339) or total fat (P=0.294) between baseline and week 8. The VIN group had significant reductions in fasting glucose (P=0.003), fasting insulin (P <0.001), and homeostatic model assessment of insulin resistance scores (P <0.001) after treatment.
Conclusions: These data do not support the findings from previous studies that indicated a link between vinegar supplementation and increased fat metabolism, specifically visceral fat reduction.
ContributorsGonzalez, Lisa Ann (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / McCoy, Maureen (Committee member) / Arizona State University (Publisher)
Created2019
Description
Epigenetic mechanisms such as DNA methylation have been found to affect metabolic processes, which leads to conditions like type 2 diabetes and obesity. The aim of this project was to validate differentially methylated cytosines (DMCs) identified in skeletal muscle from seven obese, non-diabetic women pre- and 3 months post- Roux-en-Y gastric bypass surgery. DNA samples extracted from skeletal muscle were sent to the Mayo Genotyping Core to undergo reduced representation bisulfite sequencing (RRBS). Differentially methylated cytosines at chr14.105353824 of the gene CEP170B, chr19.16437949 of the KLF2 gene, chr7.130126082 of MEST, and chr15.62457572 of C2CD4B were captured from the RRBS analysis using MethylSig. Bisulfite sequencing PCR (BSP) was performed on all DMCs listed above which resulted in no significant changes in methylation post-surgery. It was concluded that an alternate, more precise method should be used for validation of the RRBS, such as pyrosequencing.
ContributorsKelley, Conley Lane (Author) / Coletta, Dawn K. (Thesis director) / Roust, Lori R. (Committee member) / School of Human Evolution and Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Obesity has become a major area of research in many fields due to the increasing obesity rate not only in The United States, but also around the world. Research concerning obesity stigma has both physical and mental health implications. Weight bias and obesity stigma represent important research areas for health professionals as they confront these issues on a daily basis in interactions with their patients. To explore how gender, ethnicity, and a person's own BMI affect the stigma of certain weight related terms, a set of 264 participant's surveys on weight related situations on the campus of Arizona State University were analyzed. Using univariate analysis to determine frequency of words deemed most or least acceptable as well as independent t-test for gender and ANOVA for ethnicity and own BMI, we found that participant's view more clinical terms such as "unhealthy BMI" and "BMI" as acceptable words for use during a physician-patient interaction. Analysis across genders revealed the highest number of differences in terms, with females generally ranking terms across the board as less acceptable then men. Differences varied little between ethnicities; however, own BMI revealed more differences between terms; underweight participants did not rank any terms as positive. We analyzed average ATOP (Attitudes Toward Obese People) scores and found that there was no significant difference in average ATOP scores between gender and a participant's own BMI, but a statistical significance did exist between ethnic categories. This study showed that the term "obese/obesity", although normally considered to be a clinical term by many was not ranked as very positive across gender, ethnicity, or own BMI. Based on these findings, new material should be created to inform physicians on how to talk about weight related problems with certain populations of patients.
ContributorsBlasco, Drew Adair (Author) / Wutich, Amber (Thesis director) / Brewis Slade, Alexandra (Committee member) / Barrett, The Honors College (Contributor) / School of Politics and Global Studies (Contributor) / Department of Psychology (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2014-12
Description
This project explores a variety of ways of framing the problem of obesity, beginning with a multidisciplinary assessment of genetic, environmental, cultural, nutritional, and socioeconomic factors involved in the structure and the consequences of each frame. How obesity is framed as a problem has a profound impact on the kinds of solutions that may be deemed scientifically appropriate. But frames are not entirely evidence-based, inasmuch as political and moral values infuse debates about the nature of obesity. Drawing on interdisciplinary resources from bioethics and the philosophy of science, I strive to offer strategic insight in to how to navigate the complexity of these issues.
ContributorsYanamandra, Meghana (Author) / Robert, Jason (Thesis director) / Wharton, Christopher (Committee member) / Drago, Mary (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2014-05
Description
Background:
Pediatric obesity is associated with lower quality of life (QOL) and populations with high obesity rates, such as Latinos, are especially vulnerable. We examined the effects of a 12-week diabetes prevention program on changes in weight-specific QOL in Latino youth.
Method:
Fifteen obese Latino adolescents (BMI%=96.3±1.1;age=15.0±1.0) completed a 12-week intervention. Youth completed weight-specific QOL measures at baseline, post intervention, and 1-year follow-up. For comparison purposes, intervention youth were matched for age and gender with lean controls.
Results:
At baseline, obese youth exhibited significantly lower weight-specific QOL compared with lean youth (70.8±5.4 to 91.2±2.2, p<0.005). The intervention did not significantly impact weight (90.6±6.8 to 89.9±7.2kg, p=0.44). However, significant increases in weight-specific QOL were observed (70.8±20.9 to 86.2±16.9, p<0.001). Post-intervention QOL scores were no longer significantly different than lean controls (P=0.692). Data from nine youth who returned for follow-up indicated that increases in weight-specific QOL were maintained over time (90.5±4.5 to 85.8±5.9, p=0.74).
Conclusion:
These results indicate that a community-based diabetes prevention program can result in sustained improvements in weight-specific QOL among obese Latino youth. Lifestyle interventions that focus on social interaction and physical activity, rather than weight-loss per se, may help improve the psychosocial health of obese Latino youth.
Pediatric obesity is associated with lower quality of life (QOL) and populations with high obesity rates, such as Latinos, are especially vulnerable. We examined the effects of a 12-week diabetes prevention program on changes in weight-specific QOL in Latino youth.
Method:
Fifteen obese Latino adolescents (BMI%=96.3±1.1;age=15.0±1.0) completed a 12-week intervention. Youth completed weight-specific QOL measures at baseline, post intervention, and 1-year follow-up. For comparison purposes, intervention youth were matched for age and gender with lean controls.
Results:
At baseline, obese youth exhibited significantly lower weight-specific QOL compared with lean youth (70.8±5.4 to 91.2±2.2, p<0.005). The intervention did not significantly impact weight (90.6±6.8 to 89.9±7.2kg, p=0.44). However, significant increases in weight-specific QOL were observed (70.8±20.9 to 86.2±16.9, p<0.001). Post-intervention QOL scores were no longer significantly different than lean controls (P=0.692). Data from nine youth who returned for follow-up indicated that increases in weight-specific QOL were maintained over time (90.5±4.5 to 85.8±5.9, p=0.74).
Conclusion:
These results indicate that a community-based diabetes prevention program can result in sustained improvements in weight-specific QOL among obese Latino youth. Lifestyle interventions that focus on social interaction and physical activity, rather than weight-loss per se, may help improve the psychosocial health of obese Latino youth.
ContributorsBrito, Elizabeth (Author) / Shaibi, Gabriel (Thesis director) / Barroso, Cristina (Committee member) / Patrick, Donald (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2013-05
Description
Problem: Overweight and obesity are global issues. There are several strategies for weight loss and maintenance as well as general lifestyle change for overall better health. The goal is to find an easy and convenient way for people to track their food intake, either for personal use and improvement, or to be used by professionals such as registered dietitians to gather data and help improve diet. Currently food journals, food frequency questionnaires and 24-hour recall are methods that are used by registered dietitians to get an idea of what is general diet is like from their patients or clients. It was proposed that pictures taken of the meal with a phone could be used as a method of recording food intake. It would be quick and extremely easy on the client; then everything from portion size, to type of food and toppings could be analyzed quickly and conveniently. If effective it could also give rise to the ability for foods to be analyzed immediately with the text or email of the picture. Methods: subjects already participating in a separate study where they were instructed to take pictures of their meals for a difference purpose were recruited. There recorded diet intake with phone pictures were able to be used from seven subjects. Subjects took a snapshot of their meals for 3 separate days and also logged on and completed a 24 hour recall with the ASA website. The pictures were analyzed and food intake, based off the pictures was entered in the program Food Processor to generate a nutritional report. The results from the ASA 24 hour recall, based on what the subject entered, were compared to the nutritional report, generated based on review of the pictures. Nutrient values that were compared include: total energy intake (calories), protein, carbohydrates, fat, vitamin C, calcium and fiber. This was done to test if the pictures could be used as a valid source. Results: It was found that there were several problems with using the pictures as a method of analyzing food intake. Out of the seven subjects the result of only one subject was close between the two methods. All other results of calculated nutrient intake varied significantly and it did not prove to be effective to use pictures to analyze food intake. Conclusions: food intake recorded by picture method may prove to be useful in the future, however there would need to be greater compliance and training on picturing food that can be accurately analyzed. Short written explanation of food type and cooking method etc. would be most beneficial to include with actual picture. Pictures of food intake may be useful in other professional areas but as of now are not useful to generate nutritional reports.
ContributorsLouden, Karina Arianne (Author) / Johnston, Carol (Thesis director) / Morse, Lisa (Committee member) / Appel, Christy (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2013-05