Browsing by Subject "Overweight"
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Item Associations Impacting Food ChoicesReader, Shane WolfItem Beyond obesity : historical, social change approaches to improve the fitness of Americans(2014-08) Harrell, Baker Christian; Todd, JanAmerica's growing concern about fatness during the twentieth century developed in parallel with a society that made it increasingly harder to live a healthy lifestyle. Since the 1970s, sweeping political, economic, cultural, and familial changes have occurred in the United States. Many researchers argue that these changes have created an "obesogenic" environment that has contributed to the increased prevalence of overweight and obesity in America by favoring inactivity and the over consumption of highly-processed, calorie-dense foods and beverages. As a result, the field of public health has increasingly begun to recognize obesity as a "societal disease." In 2001, The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity categorized the number of overweight and obese Americans as reaching "nationwide epidemic proportions." Since that time, America has waged an all-out "war on obesity." Instead of a broader emphasis on health promotion, some public health researchers have suggested that this heightened focus on obesity is 1) guided by America's historically-rooted social disdain for fatness and 2) insufficient to improve the healthy lifestyles of Americans. In searching for a solution to the so-called "obesity epidemic," a growing number of researchers have begun to look to models of social change. After an introductory chapter describing the scope of the problem, this dissertation provides an historical analysis of two, relevant social change models. The first historical case study is an examination of the Centers for Disease Control and Prevention's VERB social marketing campaign. The second study explores the model of social movements through the history of the aerobics "boom" of 1970s America. Based on these histories, this dissertation concludes by proposing a blended approach that harnesses the strengths of both models to organize and advance America's healthy living movement.Item Dietary fiber linked to decreased inflammation in overweight minority youth(2015-05) Miller, Samantha Jean; Davis, Jaimie Nicole; Bray, Molly SObjective: To examine the relationship between diet and inflammation, and adiposity in minority youth. Design and Methods: A cross-sectional analysis of 142 overweight (≥85th BMI percentile) Hispanic and African American adolescents (14-18 y) with the following measures: anthropometrics, adiposity via magnetic resonance imagine (MRI), dietary intake via 24-hour dietary recalls, and inflammation markers from fasting blood draws utilizing a multiplex panel. Partial correlations were estimated and ANCOVA models fit to examine the relationship between dietary variables, inflammation markers, and adiposity measures with the following a priori covariates: Tanner stage, ethnicity, sex, total energy intake, total body fat, and total lean mass. Results: Inference based on ANCOVA models showed that the highest tertile of fiber intake (mean intake of 21.3 ± 6.1 g/d) versus the lowest tertile of fiber intake (mean intake of 7.4 ± 1.8 g/d) was associated with 36% lower plasminogen activator inhibitor-1 (PAI-1) (P = 0.02) and 43% lower resistin (P = 0.02), independent of covariates. Similar results were seen for insoluble fiber. No other dietary variables included in this study were associated with inflammation markers. Conclusions: These results suggest that increases in dietary fiber could play an important role in lowering inflammation and therefore metabolic disease risk in high-risk minority youth.Item Elementary School Personnel's Perceptions of and Recommendations for Managing Child Obesity: A Naturalistic Study(2012-10-19) Dixon, Mary OdumThis dissertation presents three separate studies investigating elementary school personnel's perceptions of and recommendations for managing child obesity. First, a systematic literature review will be presented with an assessment of the very limited current body of literature related to elementary school personnel's perceptions of child obesity to determine the direction of the second and third studies. The systematic review presents personnel's perspectives of (1) the extent of child obesity, (2) contributing factors of child obesity, (3) solutions for child obesity, and (4) barriers to overcoming child obesity. Second, drawing upon the systematic review, a qualitative investigation of elementary school personnel's perceptions of and recommendations for managing child obesity will be presented. Utilizing an emergent design, data collection comprised one-on-one interviews with 31 elementary school personnel. A thematic analysis was employed on raw data and a socioecological model was utilized to explain emergent themes. Participating school personnel identified the home environment and parental factors as the leading factors contributing to child obesity. Personnel also emphasized child control of dietary and physical activity choices, most notably within the home environment. Third, a qualitative case study examining an elementary physical education (P.E.) teacher's perspectives of the impact of obesity on her obese students' experiences in her classroom will be presented. A narrative framework was employed, utilizing both thematic and structural analyses to examine the narratives elicited during the interview. The thematic analysis illuminated a participation refusal pattern of obese students within this P.E. teacher's classroom. The structural analysis highlighted the participating P.E. teacher's customized intervention for her obese students' participation refusals. The combination of thematic and structural methodologies resulted in a preliminary model of the behavioral impact of obesity in this P.E. classroom, which provided a more holistic view than either method alone. Prior to this study, just seven studies had investigated elementary school personnel's perceptions of and recommendations for managing child obesity; only three of which were published in the past decade. Thus, this study is both timely and desperately needed. The valuable insights gained from participating elementary school personnel in this study provide a justification for their inclusion in future studies addressing child obesity.Item Health promotion : predicting physical activity in normal weight and overweight rural adolecents(2014-05) McAdams, Cynthia Ann Brooks; Rew, Lynn; García, Alexandra Anne, 1964-; Brown, Adama; Brown, Sharon A; Walker, LorraineAdolescent obesity is ubiquitous and is often antecedent to adverse physical and psychosocial health outcomes. Physical activity is a leading modality for preventing and treating overweight and obesity. A modified resilience framework was used in this study to examine six empirically supported risk factors for physical inactivity and low activity (i.e., body mass index, media use, parental activity, Hispanic ethnicity, minority race, and female sex) along with moderating protective resources (i.e., sense of ethnic identity, health awareness, and social connectedness). The study sample consisted of 251 adolescents, in Grades 8 and 9, recruited from three rural and economically disadvantaged school districts in the southwestern U.S. Data were retrieved from the Longitudinal Health Risk Behaviors in Youth (LongHerby; Grade 8) and Developing Health Behaviors in Middle Adolescence (DHBMA; Grade 9) databases for this secondary analysis of extant longitudinal data. One parent of each participant contributed data used in the study. Demographic analysis revealed the sample was mostly of female sex (56%), White race (81%), and non-Hispanic ethnicity (55%). A descriptive, correlational design was used to examine relationships among variables. Data analysis included correlation, linear regression, and hierarchical multiple regression techniques. The findings showed the outcome of physical activity in Grade 8 was the most statistically significant predictor of physical activity in Grade 9, using two different measures for the outcome (i.e., the Youth Risk Behavior Surveillance Scale [YRBSS] and the Adolescent Lifestyle Questionnaire [ALQ]). Two hierarchical multiple regression models explained 20% (YRBSS) and 21% (ALQ) of the variances in adolescent physical activity practices with female sex (R2Δ = .101, p < .001; YRBSS) and health awareness (R2Δ = .114, p < .001; ALQ) contributing the largest proportion to the hierarchical variances. Body mass index percentiles were not correlated with physical activity (YRBSS or ALQ), but did show a small inverse correlation with female sex (r = -151, p = ≤ .005) and a small positive relationship with Hispanic ethnicity (r = .168, p = ≤ .001). Findings of this study are congruent with previous research and could be used in planning health promotion strategies to improve adolescent physical activity.Item Internet Technology and Social Support: Are They Beneficial for Overweight Older Adolescents?(2011-10-21) Olson, Wendy AnnIn recent years, literature in the area of web-based interventions for health-related concerns has burgeoned due to the increasing popularity and accessibility of the World Wide Web. Researchers have investigated the success of web-based programs to facilitate improved health behaviors, weight loss, and social support. However, due to the relatively recent application of web-based health-behavior programs, little research has studied whether these interventions are effective with overweight older adolescents. The purpose of this study was to test the application of health behavior theory in an on-line intervention designed to address health behaviors such as exercise and nutrition in a sample of overweight older adolescents. Using a pre-test, post-test, randomized, control group design, participants (n=71) were randomly assigned to either the comparison (Information) group, or the treatment (Information plus Discussion) group. Specific aims of the study were: 1) To test a new health behavior theory, the Model of Influence of Social Support on Health Behavior (MISSHRB), in a group of older adolescents; 2) To determine the feasibility and clinical utility of an internet intervention for social support for overweight older adolescents, and 3) To examine the impact of that intervention on the MISSHB variables. Results provided partial support for the MISSHRB, with social support correlating significantly with expectancies, attitudes, and perceived behavioral control. Results also provided support for the hypotheses that family general support, family specific support, attitudes, and engagement in health behaviors would improve over time. Results supported the feasibility of using an internet intervention with overweight older adolescents, with participants easily engaging in the study, fulfilling study requirements and reporting improved perceptions of the utility of online groups for providing social support. Additionally, results approached significance for medical outcomes, with trends representing Body Mass Index decrease over time, and suggesting that the Information plus Discussion group lost more weight than the Information group. These data suggest that internet information and discussion groups have promise as a means of social support for older overweight adolescents who are interested in improving their health behaviors. These results also provide information about the usefulness of web-based programs in facilitating overweight older adolescents? engagement in health-related behaviors and the utilization of internet support groups for other marginalized or socially stigmatized groups.Item Mechanisms of heat stress- and obesity-induced reductions in orthostatic tolerance(2013-08) Lee, Joshua Floyd; Brothers, Robert MatthewThese studies investigated 1) mechanisms underlying the well-established reduction in orthostatic tolerance (OT) that occurs in humans during heat stress (HS) relative to normothermia (NT) with particular focus on determining factors contributing to the high degree of inter-individual variability in this phenomenon; and 2) influence of obesity on OT, and mechanisms underlying reduced OT, should it exist. In Study #1, OT was assessed during lower body negative pressure (LBNP), and quantified with a cumulative stress index (CSI). Differences in CSI (CSIdiff) between thermal conditions were used to categorize individuals most (LargeDiff) and least (SmallDiff) affected by HS (P<0.001). Cerebral perfusion [indexed as middle cerebral artery blood velocity (MCA Vm̳̳e̳a̳n̳)] was reduced during HS compared to NT (P<0.001); however, the magnitude of reduction did not differ between groups (P=0.51). In the initial stage of LBNP during HS (LBNP20), MCA Vm̳̳e̳a̳n̳ and end-tidal CO₂ (PETC̳O̳₂) were reduced, and heart rate (HR) was higher in the LargeDiff group compared to SmallDiff group (all P<0.05); yet, mean arterial pressure was similar (P=0.23) suggesting impaired mechanisms regulating MCA Vm̳̳e̳a̳n̳ may affect OT. In Study #2, mechanisms of cerebrovascular control were compared in LargeDiff and SmallDiff individuals. Although estimates of cerebral autoregulation (CA) and cerebrovascular reactivity to CO₂ were improved and reduced respectively, during HS compared to NT (all P<0.05), no relationship existed between CA or cerebral reactivity to hypocapnia and CSIdiff (all P>0.05). In Study #3, OT was lower in obese compared to non-obese individuals (P<0.01), and BMI was negatively correlated with CSI (R = -0.47; P < 0.01). HR was elevated at rest and in every level of LBNP (all P<0.05) in obese; yet, peak HR during LBNP was similar between groups (P=0.90). MCA Vm̳̳e̳a̳n̳ and cerebral vascular conductance were similar at rest and during LBNP (both P>0.05), and CA was similar between groups (P>0.05). In summary, a high HR prior to-, and a high HR and reduced MCA Vm̳̳e̳a̳n̳ at the onset of an orthostatic challenge result in reduced OT during HS in healthy individuals; however, reduced OT in obese is related to a higher %peak HR at rest.Item Physical activity in early adolescent girls : an examination of biological, affective, interpersonal and sociocultural influences(2013-08) Standiford, Anne Elizabeth; García, Alexandra Anne, 1964-; Rew, LynnPediatric overweight is defined as a body mass index (BMI) for age of 85th-95th percentile, and occurs in approximately 33.6% of adolescents 12-19 years of age. Hispanic adolescents are disproportionately at risk for overweight. Excess weight can predispose adolescents to develop diabetes mellitus type 2, coronary artery disease, hypertension, hypercholesterolemia, sleep apnea, osteoporosis, asthma, and certain types of cancer, whereas physical activity can help prevent and treat these diseases. Little is known about the factors that contribute to physical activity in Hispanic adolescent girls. The purpose of this study was to examine and compare the influence of personal characteristics, perceptual influences, interpersonal influences and sociocultural influences on physical activity in White and Hispanic adolescent girls. The theoretical framework for this study was self-designed--the Physical Activity Lifestyle Model. Data for this cross-sectional study was collected from girls age 11-14 who presented to the Children's Wellness Center in Del Valle, TX (N = 121) in the summers of 2011 and 2012. Most participants self-identified as Hispanic (n = 106). Participants completed a survey consisting of a 1-day physical activity recall, a demographic questionnaire, and several validated (primarily Likert-type) questionnaires. Height and weight were measured in the clinic. Data analysis began with descriptive analysis (mean, standard deviation and percentage) of demographic characteristics, dependent and independent variables, then Pearson correlations, and finally multiple linear regression to determine the influence of the independent variables on physical activity. No significant differences were found between ethnic groups on age, grade or school (p > .05). Physical activity was significantly related to body image (r = .189, p < .05), friend social support (r = .279, p < .01), and family social support (r = .401, p < .01). In addition, physical activity significantly predicted BMI percentile (B = -.043, SE = .019, t = -2.249, p = .027), appearance-related media messages (B = .259, SE = .127, t = 2.038, p = .044), pressures to be thin (B = .311, SE = .149, t = 2.082, p = .040), family social support for physical activity (B = .089, SE = .042, t = 2.139, p = .035), body image (B = .367, SE = .123, t = 2.987, p = .004), and physical activity enjoyment (B = .083, SE = .040, t = 2.089, p = .040). When designing an intervention to promote physical activity, health care providers and educators should consider that multiple external factors influence physical activity participation in Hispanic adolescent girls. Healthcare providers should involve parents and siblings in physical activity interventions for overweight adolescent girls. Interventions should be tailored to work with the adolescent girls' physical and social environment. Public health nurses should work with schools and communities to increase physical activity opportunities for adolescent girls in physical education classes, girls' sports, and after-school programs.Item Trajectories, predictors, and adolescent health outcomes of childhood weight gain : a growth mixture model(2014-12) Bichteler, Anne; Gershoff, Elizabeth T.Obesity, as defined as BMI at or above the 95th percentile on the Centers for Disease Control and Prevention’s growth charts, has increased almost 3-fold among children in the United States since 1980. Overweight in adolescence has been associated with increased fat retention and high blood pressure in adulthood, among other symptoms of metabolic syndrome. However, normative patterns of weight change in childhood have not been developed. Groups of children may follow different trajectory patterns of BMI change over time. If common trajectory patterns could be identified, and their risk factors and outcomes understood, more nuanced intervention with families and children at risk for obesity could be developed. This study used a national dataset of 1,364 children whose weight and length was measured 12 times from birth through 15 ½ years. Testing both latent class growth analysis and growth mixture modeling identified four distinct subgroups, or classes, of BMI growth trajectory from 24 months – 8th grade. These classes were compared on numerous demographic, biological, and psychosocial risk factors identified in previous research as related to obesity. Classes were differentiated primarily on the child’s BMI at 15 months, the mother’s BMI at 15 months, birth weight for age, and percent increase in birth weight. Being male, Black, and lower SES were also related to membership in the higher-BMI trajectory classes. Of the psychosocial factors, maternal sensitivity, maternal depression, and attachment classification were also related to BMI class. Membership in these trajectories strongly predicted weight-related and blood-pressure outcomes at 15 ½ years over and above individual risk factors, demonstrating that patterns of change themselves are highly influential. The best-fitting models of weight-related outcomes at 15 ½ years included change trajectory in combination with biological, psychosocial, and SES risk factors from 0-24 months, with R² ranging from .31 = .50. Characteristics predicting adolescent overweight can be identified in the first years of life and should trigger the development and implementation of early intervention protocols in obstetrics and pediatrics.