Matching Items (26)
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- All Subjects: Obesity
- Creators: School of Life Sciences
- Creators: Gaesser, Glenn A
Description
Cardiovascular disease (CVD) is the number one cause of death in the United States and type 2 diabetes (T2D) and obesity lead to cardiovascular disease. Obese adults are more susceptible to CVD compared to their non-obese counterparts. Exercise training leads to large reductions in the risk of CVD and T2D. Recent evidence suggests high-intensity interval training (HIT) may yield similar or superior benefits in a shorter amount of time compared to traditional continuous exercise training. The purpose of this study was to compare the effects of HIT to continuous (CONT) exercise training for the improvement of endothelial function, glucose control, and visceral adipose tissue. Seventeen obese men (N=9) and women (N=8) were randomized to eight weeks of either HIT (N=9, age=34 years, BMI=37.6 kg/m2) or CONT (N=8, age=34 years, BMI=34.6 kg/m2) exercise 3 days/week for 8 weeks. Endothelial function was assessed via flow-mediated dilation (FMD), glucose control was assessed via continuous glucose monitoring (CGM), and visceral adipose tissue and body composition was measured with an iDXA. Incremental exercise testing was performed at baseline, 4 weeks, and 8 weeks. There were no changes in weight, fat mass, or visceral adipose tissue measured by the iDXA, but there was a significant reduction in body fat that did not differ by group (46±6.3 to 45.4±6.6%, P=0.025). HIT led to a significantly greater improvement in FMD compared to CONT exercise (HIT: 5.1 to 9.0%; CONT: 5.0 to 2.6%, P=0.006). Average 24-hour glucose was not improved over the whole group and there were no group x time interactions for CGM data (HIT: 103.9 to 98.2 mg/dl; CONT: 99.9 to 100.2 mg/dl, P>0.05). When statistical analysis included only the subjects who started with an average glucose at baseline > 100 mg/dl, there was a significant improvement in glucose control overall, but no group x time interaction (107.8 to 94.2 mg/dl, P=0.027). Eight weeks of HIT led to superior improvements in endothelial function and similar improvements in glucose control in obese subjects at risk for T2D and CVD. HIT was shown to have comparable or superior health benefits in this obese sample with a 36% lower total exercise time commitment.
ContributorsSawyer, Brandon J (Author) / Gaesser, Glenn A (Thesis advisor) / Shaibi, Gabriel (Committee member) / Lee, Chong (Committee member) / Swan, Pamela (Committee member) / Buman, Matthew (Committee member) / Arizona State University (Publisher)
Created2013
Description
In adults, consuming a high-fat meal can induce endothelial dysfunction while exercise may mitigate postprandial endothelial dysfunction. Whether exercise is protective against postprandial endothelial dysfunction in obese youth is unknown. The purpose of this study was to determine if high-intensity interval exercise (HIIE) performed the evening prior to a high-fat meal protects against postprandial endothelial dysfunction in obese adolescent males. Fourteen obese adolescent males (BMI%tile=98.5±0.6; 14.3±1.0yrs) completed the study. After initial screening, participants arrived, fasted at 9:00 in the morning where brachial artery flow-mediated dilation (FMD) was measured using duplex ultrasound after 20min of supine rest (7.0±3.0%) and completed a maximal exercise test on a cycle ergometer (VO2peak=2.6±0.5 L/min). Participants were randomized and completed 2 conditions: a morning high-fat meal challenge with evening prior HIIE (EX+M) or a morning high-fat meal challenge without prior exercise (MO). The EX+M condition included a single HIIE session on a cycle ergometer (8 X 2min at ≥90%HRmax, with 2min active recovery between bouts, 42min total) which was performed at 17:00 the evening prior to the meal challenge. In both conditions, a mixed-meal was tailored to participants body weight consisting of 0.7g of fat/kg of body weight consumed (889±95kcal; 65% Fat, 30% CHO). FMD was measured at fasting (>10hrs) and subsequently measured at 2hr and 4hr after high-fat meal consumption. Exercise did not improve fasting FMD (7.5±3.0 vs. 7.4±2.8%, P=0.927; EX+M and MO, respectively). Despite consuming a high-fat meal, FMD was not reduced at 2hr (8.4±3.4 vs. 7.6±3.9%; EX+M and MO, respectively) or 4hr (8.8±3.9 vs. 8.6±4.0%; EX+M and MO, respectively) in either condition and no differences were observed between condition (p(condition*time)=0.928). These observations remained after adjusting for baseline artery diameter and shear rate. We observed that HIIE, the evening prior, had no effect on fasting or postprandial endothelial function when compared with a meal only condition. Future research should examine whether exercise training may be able to improve postprandial endothelial function rather than a single acute bout in obese youth.
ContributorsRyder, Justin Ross (Author) / Shaibi, Gabriel Q (Thesis advisor) / Gaesser, Glenn A (Committee member) / Vega-Lopez, Sonia (Committee member) / Crespo, Noe C (Committee member) / Katsanos, Christos (Committee member) / Arizona State University (Publisher)
Created2014
Description
Cardiovascular disease and diabetes are major health burdens. Diabetes is a primary risk factor of cardiovascular disease, and there is a strong link between obesity and risk of developing diabetes. With the prevalence of prediabetes highest among overweight/obese individuals, investigation into preventative strategies are needed. Aerobic exercise is a potent stimulus for both insulin and non-insulin dependent glucose uptake into the skeletal muscle. A single exercise session can improve insulin sensitivity within hours after exercise. The effects of intensity, type, and volume of exercise on glucose homeostasis have been studied extensively; however, controlling for muscle contraction frequency with a constant exercise intensity and workload has not been examined. The purpose of this study was to compare muscle contraction frequency during aerobic exercise by altering cycling cadence on insulin sensitivity and vascular health. Eleven obese males (age=28yr, BMI=35kg/m2) completed three conditions in random order: 1) control-no exercise; 2) 45-min cycling at 45 revolutions per minute (45RPM) at 65-75%VO2max; 3) 45-min cycling at 90RPM at 65-75%VO2max. Glucose control and insulin sensitivity were assessed with oral glucose tolerance tests (OGTT) 4 hours post-exercise. Vascular health was assessed via flow-mediated dilation (FMD) pre-exercise, 1-hr and 2-hr post exercise and ambulatory blood pressure was assessed pre-exercise, and continually every 15 min post-exercise. Linear mixed models were used to compare the mean differences in outcome variables. There were no significant differences found between control and both exercise conditions for all OGTT outcomes and no differences were found between control and exercise in FMD (all, p>0.05). Significant effects for exercise were found for both brachial and central blood pressure measures. Brachial systolic blood pressures were lower at 2- and 4-hr post-exercise by approximately -10 and -8mmHg, respectively (p<0.001 and p=0.004) versus control. Central systolic blood pressures were lower at 2-, 3-, and 4-hr post-exercise by approximately -8, -9 and -6mmHg, respectively (p<0.001, p=0.021 and p=0.004) versus control. In conclusion, aerobic exercise, regardless of muscle contraction frequency, were unable to effect glucose control and insulin sensitivity. Similarly, there was no effect on vascular function. However, there was a significant effect of aerobic exercise on reducing post-exercise blood pressure.
ContributorsJarrett, Catherine Lee (Author) / Gaesser, Glenn A (Thesis advisor) / Angadi, Siddhartha S (Committee member) / Dickinson, Jared M (Committee member) / Whisner, Corrie M (Committee member) / Todd, Michael W (Committee member) / Arizona State University (Publisher)
Created2017
Description
Dogs' health and wellbeing is of great importance to their owners. The most common nutritional problem for pet dogs is obesity, with 22-40% of pet dogs being classified as overweight or obese. With many adverse health effects associated with obesity, this is a major concern for owners and veterinarians. The degree to which dogs enjoy consuming certain foods can have substantial implications for their body weight, so it is important to understand which aspects of foods make them appealing to dogs. This study aimed to determine whether nutritional aspects of commercial dog foods predict dogs' preferences for those foods. It was found that consumption preference is positively correlated with protein content (p < .001), therefore implying that the protein content of commercial dry dog foods may predict dogs' consumption preferences. Consumption preferences were not predicted by other available measures of food content or caloric value. Dogs' preference for foods high in protein content may be due to the satiating effect of protein. Since foods high in protein both reduce the amount of energy consumed and are found to be palatable to dogs, high-protein dog foods may offer a way for dog food manufacturers, veterinarians, and pet owners to combat obesity in pet dogs.
ContributorsPrevost, Emily Danielle (Author) / Wynne, Clive (Thesis director) / Hall, Nathaniel (Committee member) / School of Life Sciences (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
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
Obesity is a growing issue in the Western world, as well as other international countries. This is leading to increases in complications associated with obesity. One such complication is osteoarthritis (OA) of load bearing joints that requires surgical treatment by total knee arthroplasty (TKA). Obesity is also associated with an increase in surgical complications that may lead to poor TKA outcomes. Additionally, the female gender is also known to be associated with increased rates of severe, clinical OA. This study was designed to determine the comparative efficacy of two knee implants in the obese female population through retrospective chart review and data analysis. The implants differ in their level of constraint, with the total stabilizing (TS) being more constrained than the posterior stabilizing (PS). We hypothesized that the TS implants would be associated with improved functional outcomes in the obese female population. The TS implant was observed to be associated with earlier improvement of both passive and active range of motion. This implant also showed greater improvement from pre-operative condition in stability, rejecting our null hypothesis and supporting our hypothesis.
ContributorsWorhacz, Kellen Michael (Author) / Hinrichs, Richard (Thesis director) / Jacofsky, Marc (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
There has been an alarming rise in the prevalence of obesity which has been attributed to the paralleled rise in consumption of high-fat foods. It’s commonly accepted that high-fat diets can lead to increased weight gain, however not all fats have the same physiological action. This study primarily focuses on the effect of canola oil, a monounsaturated fat, on energy homeostasis and body composition when it’s given as a supplement to a high-fat diet composed of saturated fatty acid. Rodent models were divided into three dietary groups: 1) low-fat diet (LFD), 2) high-fat diet (HFD) and 3) canola oils supplemented HFD (HF+CAN). After 4 weeks of dietary intervention, samples of epididymal fat, perinephric fat, and liver were analyzed across the three groups to see if the changes in energy homeostasis could be explained by the cellular behavior and composition of these tissues. Interestingly, the supplement of canola oil appeared to reverse the deleterious effects of a saturated fat diet, reverting energy intake, body weight gain and adipose tissue sizes to that (if not lower than that) of the LFD group. The only exception to this effect was the liver: the livers remained larger and fattier than those of the HFD. This occurrence is possibly due to a decrease in free fatty acid uptake in the adipose tissues—resulting in smaller adipose tissue sizes—and increased fatty acid uptake in the liver. The mechanism by which this occurs has yet to be elucidated and will be the primary focus of upcoming studies on the effect of monounsaturated fat on other diets.
ContributorsZuo, Connie Wanda (Author) / Washo-Krupps, Delon (Thesis director) / Deviche, Pierre (Committee member) / Herman, Richard (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
In the United States, the prevalence of pediatric obesity has increased to 17% in the general population and even more so in the Hispanic pediatric population to 22.4%. These children are at a higher risk for associated comorbidities, including cardiovascular disease and insulin resistance. The purpose of the following study is to determine the effectiveness of the Nutrition and Health Awareness curriculum at reducing childhood obesity by evaluating alterations in the gut microbial composition, diet, and overall health of the students throughout the five-week program. Nutrition and Health Awareness (NHA) is a student organization that strives to reduce the prevalence of obesity, diabetes, and cardiovascular diseases, specifically in children, by providing active nutrition education services through peer mentoring in elementary schools and community programs. This study went through ASU's Institutional Review Board process and all forms were translated into Spanish. The control group maintained their normal routines and the experimental group received the 5 week NHA program and then continued with their normal routines. Anthropometric measures (Body Mass Index, waist-to-hip ratio, and blood pressure), diet measures (Hispanic food frequency questionnaire), fecal swabs, and content surveys were collected on weeks 0, 5, and 8. Contrary to expected, alpha diversity, kilocalorie intake, and macronutrient intake decreased as the study progressed for both the control and experimental groups. Anthropometric measurements were relatively stable. Though not statistically significant, the greatest difference in time points is between weeks 1 and 8. This decrease in alpha diversity and kilocalorie intake could be due to a change in environment since the children started school on week 8. Future implications of this study are that parental involvement is necessary for an effective, sustainable change in these children. More research in different settings is necessary to determine NHA's effectiveness
ContributorsPatel, Kapila Cristina (Author) / Krajmalnik-Brown, Rosa (Thesis director) / Whisner, Corrie (Committee member) / School of Nutrition and Health Promotion (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
It is presently believed that brown adipose tissue (BAT) is an important tissue in the control of obesity because it has the propensity to increase energy expenditure. The purpose of this study was to attempt to quantify the thermogenesis of BAT when four rats were exposed to a progression of low-fat to high-fat diet. Exogenous norepinephrine (NE) injections (dose of 0.25 mg/kg i.p.) were administered in order to elicit a temperature response, where increases in temperature indicate increased activity. Temperatures were measured via temperature sensing transponders that had been inserted at the following three sites: interscapular BAT (iBAT), the abdomen (core), and lower back (reference). Data showed increased BAT activity during acute (2-3 weeks) high fat diet (HFD) in comparison to low fat diet (LFD), but a moderate to marked decrease in BAT activity during chronic HFD (6-8 weeks) when compared to acute HFD. This suggests that while a HFD may initially stimulate BAT in the short-term, a long-term HFD diet may have negative effects on BAT activation.
ContributorsSivak, Hanna (Author) / Sweazea, Karen (Thesis director) / Herman, Richard (Committee member) / Caplan, Michael (Committee member) / School of Life Sciences (Contributor) / College of Integrative Sciences and Arts (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Obesity has developed into a worldwide health problem that is associated with many risks. The elements causing obesity are complex and numerous including behavioral, psychological, and physiological. Traditional methods of weight loss have demonstrated short-lived positive health benefits and minimal long-term weight loss, which has led to the prevalence of bariatric surgery as an answer to long-term weight loss for Class III obesity. Gastric bypass surgery has become especially popular for its numerous benefits including successful weight loss, improvements in obesity-related diseases, and increased lifespan. Bariatric surgery is still not a perfect solution. Negative effects after surgery range from surgical complications and vitamin deficiencies to altered hormonal levels and metabolic rates. Many questions regarding bariatric surgery still remain including the impact of adolescent bariatric surgery, long-term bone effects, and long-term psychosocial and lifestyle components of bariatric patients. Understanding the good, the bad, and several of the remaining questions regarding bariatric surgery, will help health professionals be more appreciative of the complexity of treating their obese patients.
ContributorsStich, Alexandra M. (Author) / Swan, Pamela (Thesis director) / Sebren, Ann (Committee member) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05