Life Sciences Commons^™

Milk-Fat Intake And Differences In Abdominal Adiposity And Bmi: Evidence Based On 13,544 Randomly Selected Adults, Klarissa Rae Wilkinson

Theses and Dissertations

The primary objective of this study was to evaluate the relationship between milk-fat intake and obesity, particularly abdominal obesity, in 13,544 U.S. adults. A secondary objective was to determine the extent to which the association was influenced by multiple potential confounding variables. This cross-sectional study used data from the 2011–2016 National Health and Nutrition Examination Survey (NHANES). Level of milk-fat content regularly consumed was the exposure variable. Body mass index (BMI) and sagittal abdominal diameter (SAD), a measure of abdominal obesity, were the outcome variables. SAD correlates strongly with visceral fat, when measured by computed tomography, and has been shown …

Physical Activity Level And Insulin Resistance In 6,500 Nhanes Adults: The Role Of Abdominal Obesity, James R Fowler

Theses and Dissertations

OBJECTIVE: This cross-sectional study investigated insulin resistance (IR) variation across physical activity (PA) levels in U.S. adults. METHODS: MET-minutes were utilized to quantify PA using 2 methods: 4 categories were based on relative MET-minutes, and 5 were based on U.S. PA guidelines. IR was indexed using the homeostatic model assessment (HOMA). Effect modification was tested by dividing waist circumferences into sex-specific quartiles, and then evaluating the relationship between PA and HOMA-IR within each quartile separately. RESULTS: Relative PA was associated with HOMA-IR after controlling for demographic and demographic and lifestyle covariates (F = 11.5, P < 0.0001 and F = 6.0, P = 0.0012, respectively). Adjusting for demographic and demographic and lifestyle covariates also revealed relationships between guideline-based PA and HOMA-IR (F = 8.0, P < 0.0001 and F = 4.9, P = 0.0017, respectively). Controlling for waist circumference with the other covariates nullified the relationship between PA and HOMA-IR. Effect modification testing showed that when the sample was delimited to adults with extra-large waists (Quartile 4), relative (F = 5.6, P = 0.0019), and guideline-based PA (F = 3.7, P = 0.0098) and HOMA-IR were related. PA and HOMA-IR were not related within the other quartiles. CONCLUSION: High levels of PA may play a meaningful role in glucose and insulin metabolism in those with abdominal obesity, but not in adults with smaller waists.

Gut Microbiota Regulates The Interplay Between Diet And Genetics To Influence Insulin Resistance, Jeralyn Jones Franson

Theses and Dissertations

Insulin resistance and obesity are major public health concerns. The impact of diet and genetics on insulin resistance and obesity is well accepted. Additionally, the gut microbiota has been shown to influence obesity and metabolic disorders. However, much remains to be understood about the role of gut microbiota in the development of insulin resistance and obesity. We utilized a mouse model lacking PAS kinase, a protein involved in cellular metabolism, in order to better understand the relationship between diet, genetics and the gut microbiota. Previous research has shown that mice lacking PAS kinase were protected from the effects of a …

Sagittal Abdominal Diameter, Waist Circumference, And Bmi As Predictors Of Multiple Measures Of Glucose Metabolism: An Nhanes Investigation Of U.S. Adults, Shelby Anne Firouzi

Theses and Dissertations

OBJECTIVE: The key objective of the present investigation was to compare associations between sagittal abdominal diameter (SAD), waist circumference, and BMI to the oral glucose tolerance test (OGTT), along with fasting glucose, HbA1c, and HOMA-IR, in a nationally representative sample of U.S. adults. The study also analyzed the effect of multiple covariates on the anthropometric and glucose metabolism associations. METHODS: A cross-sectional design, including 3,582 subjects, was used. SAD was assessed using an abdominal caliper. All other data were collected following strict NHANES protocol. The OGTT was the primary variable used to index glucose metabolism. Fasting glucose, HbA1c, and HOMA-IR …

Validity And Reliability Of A Photographic Method Of Assessing Body Composition, Elizabeth Z. Macdonald

Theses and Dissertations

The LeanScreenTM app uses photographs and touchscreen technology of an iPad or iPhone to estimate body composition using the Department of Defense (DoD) prediction equations that use cirumference measurements of the neck, abdomen, waist, and hips. The purpose of this study was to determine the validity and reliability of the LeanScreenTM app in 148 weight-stable adults (82 men, 66 women) who were normal weight, overweight, or obese as defined by body mass index. The percent body fat (%BF) of each subject was estimated during one visit using dual-energy x-ray absorptiometery (DXA) as the criterion measure, and three field methods: the …

The Relationship Between Television Viewing Time And Cardiorespiratory Fitness In Adult Women, Peter Jacob Arens

Theses and Dissertations

Purpose: The present investigation was conducted to assess the relationship between television viewing time and cardiorespiratory fitness. Design: Cross-sectional. Setting: Intermountain West. Participants: 302 middle-aged women. Method: TV viewing was assessed using a questionnaire. Cardiorespiratory fitness was measured using a maximal graded treadmill test. Physical activity (PA) was evaluated using Actigraph accelerometers worn over seven consecutive days, while body fat percentage (BF%) was measured using air displacement plethysmography (Bod Pod). Results: (Mean ± SD) age: 40.2 ± 3.0 years. VO2max of the frequent (≥ 3hrs/day) TV group (32.6 ± 6.4) was significantly lower than both the moderate (1-2 hrs/day) (36.2 …

The Relationship Between Sleep Deprivation, Food Motivation, And Energy Intake In Normal-Weight And Obese Females, Lora Light Romney

Theses and Dissertations

Objective: Sleep deprivation has been proposed as a potential correlate of obesity, particularly influencing energy intake. Therefore, the purpose of this study was to compare neural indices of attention related to food motivation and energy intake in normal-weight and obese women under two separate sleep conditions: 1) sleep-restricted (<5 hours) and 2) recommended sleep (~8 hours). This study used a combined cross-over and ex post facto design with condition order counter-balanced. Methods: Twenty-two normal-weight (age=30.9±9.5y, BMI=22.0±1.6 kg/m2) and 18 obese (age=29.7±10.7 y, BMI=36.4±5.3 kg/m2) women completed both sleep conditions. To confirm sleep levels, participants recorded sleep quality and quantity via sleep logs and wore a wrist actigraph. Following each condition, participants reported to the laboratory under the same fed state (energy shake ~10% of total daily needs) to verify they followed the sleep protocol. Subsequently, motivation for food was tested using electroencephalogram (EEG); participants completed a computerized passive-viewing task of food and flowers, while event-related brain potentials (ERPs) were recorded. After EEG testing, participants continued their normal routine but recorded all energy intake using weighed food scales. There were no instructions or limitations on dietary intake. Analyses included P300 and LPP amplitudes in response to picture type, total next day energy intake, and energy intake by several periods of the day. Results: Participants averaged 4.7±0.4 hours of sleep during the sleep-restricted condition and 7.7±0.3 hours during the recommended sleep condition (F=1057.02; P<0.0001). There was no group*condition interaction for next day food motivation (P300: F<2.896, P>0.09; LPP: F<2.967, P>0.093). Next day total energy intake also did not differ by group*condition (F=1.81; P=0.187). When participants were pooled, there was no difference in energy intake by sleep condition (F=0.00; P=0.953). However, when participants’ energy intake was analyzed during the lunch period (following testing to 1:30pm) there was a …

Effects Of Telephone Weight Loss Coaching On Body Composition In Adults: A Randomized Controlled Study, Amy Jensen Cook

Theses and Dissertations

Objective: To determine the extent to which coaching over the telephone is an effective method in promoting the loss of body weight and body fat percentage. Research Methods and Procedures: Over a period of four months, in a randomized, double blind, placebo-controlled study, 120 overweight and obese (BMI 25-35 kg/m²) adults either received telephone coaching or no coaching. In addition, each participant was randomly assigned to take a supplement or placebo daily. Body weight and body fat percentage were measured at baseline, two months, and four months. Body weight was measured on an electronic scale and body fat percentage was …

Soft Drink Consumption And Changes In Body Composition In 170 Women: A 4-Year Prospective Study, Jared Michael Tucker

Theses and Dissertations

Background: In recent history, there have been significant increases in both soft drink consumption and the prevalence of obesity throughout the developed world. To help curb the obesity epidemic, a better understanding of the behaviors contributing to weight and fat gain is vital.

Objective: To examine the extent to which soft drink consumption is predictive of changes in body composition in middle-aged women over a 4-year period, while statistically controlling for age, energy intake, physical activity, and menopause status.

Design: A prospective cohort design over 48 months with no intervention. Self-reported soft drink consumption was used to predict changes in …

Body Mass Index And Soft Drink Consumption Among Adolescents, Olivia Love Mccord

Theses and Dissertations

Objective: To determine the relationship between body mass index (BMI) and soft drink consumption among adolescents. It is hypothesized that soft drink consumption contributes to overweight and obesity among adolescents.

Background: Research examining the relationship between body mass index and soft drink consumption is inconsistent. Several studies have found a negative association between total sugar intake and BMI; however, others have found a link between sugar-sweetened drinks and obesity. There are no known studies that have controlled for physical activity.

Data and Methods: Data on approximately 225 adolescents were used. Frequency of soft drink consumption, type of milk, and calcium …