Matching Items (6)

Energy Expenditure: Relationships Between Ghrelin And Body Composition In Healthy Young Men

Description

Ghrelin is an acylated peptide hormone with far reaching affects within the human body. Consisting of both central and peripheral effects, ghrelin has been the topic of research since its

Ghrelin is an acylated peptide hormone with far reaching affects within the human body. Consisting of both central and peripheral effects, ghrelin has been the topic of research since its discovery in 1999. These effects include energy maintenance, cardiovascular health, growth hormone mediation, glucose homeostasis, muscle growth and atrophy, and bone metabolism, all of which work in concert with other well-known physiological mechanisms. With the goal to reproduce a similar study done in females in males, this study hypothesized that ghrelin would present an inverse relationship with a young healthy male population's resting metabolic rates. The study consisted of taking resting metabolic rate measurements, dual-energy X-ray absorptiometry, blood ghrelin testing, and statistical analysis of the data. The hypothesis was shown to be incorrect as the data showed a positive correlation, albeit, with very low statistical significance. Despite the data, past research has shown ghrelin plays a major role in fat gain, fat loss, and energy expenditure. Obesity is plaguing the world and becoming a major pubic health concern. It is necessary to explore causality and casual relationships in order to better understand and combat obesity. Therefore, further research is warranted into ghrelin and energy expenditure as a biomarker or novel treatment for obesity.

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Created

Date Created
  • 2016-12

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Effects of a Tai Chi/Qigong Intervention on Body Composition, Sleep Quality, and Emotional Eating in Midlife and Older Women

Description

Weight gain and unfavorable body composition are prevalent among midlife and older women; shifts in these characteristics can have detrimental implications on emotional and physical health and longevity. Efforts

Weight gain and unfavorable body composition are prevalent among midlife and older women; shifts in these characteristics can have detrimental implications on emotional and physical health and longevity. Efforts to attenuate weight-related factors detailing the potential development of obesity are traditionally driven by manipulation of nutrition and/or physical activity; however, sustained results are limited. Novel and integrative approaches are needed to reduce the burden of adverse changes in weight and associated consequences.

This dissertation is built around a model of effects of Tai Chi/Qigong in body composition and a pilot test of this intervention and model factors in a group of midlife/older women (N = 36). Three resulting manuscripts include: 1) a proposed biobehavioral model detailing how a Tai Chi/Qigong intervention may improve weight-related outcomes through psychological, behavioral, and physiological pathways, 2) a paper examining pre- to post- intervention differences in the primary outcomes of percent body fat, sleep quality, and emotional eating and the exploratory outcomes of perceived stress, mood state, mindfulness, self-compassion and body awareness; and 3) an exploratory analysis examining correlations between primary (sleep quality, emotional eating), exploratory (perceived stress, mood state, mindfulness, self-compassion and body awareness), and neurophysiological (heart rate variability) outcomes of interest—further, regression models were conducted to explore the predictive value of the independent variables on the dependent variables and associated changes.

In manuscript two, dependent t-tests were used to assess pre/post-differences (percent body fat and survey measures); this single group study (8-weeks of Tai Chi/Qigong) did not have a control group. Results of manuscript two demonstrate significant changes in sleep quality (p = .04), perceived stress (p = .05), and body awareness (p = .01). Findings of manuscript three indicate changes in the dependent variable of sleep quality were partially explained by perceived stress (adjusted R2 = 13.4%) and changes in the dependent variable of emotional eating were significantly explained by self-compassion (adjusted R2 = 42.1%). In the context of weight gain and unfavorable body composition in midlife/older women, results of this pilot study, using a standardized Tai Chi/Qigong intervention, indicate that select psycho-emotional factors may be important to explore further.

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Created

Date Created
  • 2019

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Effects of a fat-sugar supplemented diet, with and without exercise training, on body fat mass and selected cardiometabolic risk markers in overweight and obese, sedentary males

Description

The winter holiday period has been highlighted as a major risk period for weight gain due to excess caloric intake in the form of fat and sugar. Furthermore, diets high

The winter holiday period has been highlighted as a major risk period for weight gain due to excess caloric intake in the form of fat and sugar. Furthermore, diets high in fat and sugar have been implicated in the pathogenesis of diabetes and cardiovascular disease. Exercise aids in the prevention of weight/fat gain, and prevents deleterious changes in cardiometabolic function. The objective of this study was to examine the effects of a fat-sugar supplemented diet, with and without two different exercise training protocols, on body composition, glycemic control and other markers of cardiovascular disease in an at-risk population of overweight and obese males. Twenty-seven, healthy overweight/obese (BMI >25 kg/m2) males were fed 2 donuts per day, 6 days/week, for four weeks, while maintaining their current diet. In addition, all subjects were randomized to one of the following conditions: sedentary control, 1,000 kcal/week moderate-intensity continuous training (MICT) (50% of peak oxygen consumption), or 1,000 kcal/week high-intensity interval training (HIIT) (90-95% of peak heart rate). Supervised exercise training was performed 4 days/week on a cycle ergometer. Changes in body weight and composition, endothelial function, arterial stiffness, glycemic control, blood lipids and cardiorespiratory fitness (CRF) were assessed before and after the intervention. Body weight, lean mass and visceral fat increased significantly in HIIT (p<0.05) and were unchanged in MICT. There was a trend for a significant increase in body weight (p=0.07) and lean mass (p=0.11) in control. Glycemic control during the 2-h OGTT improved significantly in MICT and control, with no change in HIIT. Hepatic insulin resistance index (IRI) and 30-min insulin during the OGTT improved significantly after MICT and worsened following control (p=0.03), while HIIT was unchanged. CRF increased significantly in both HIIT and MICT, with no change in control (p<0.001). There were no significant changes in other markers of cardiovascular disease. The addition of a fat-sugar supplement (~14,500 kcal) over a 4-week period was not sufficient to induce deleterious changes in body composition and cardiometabolic health in overweight/obese young males. Exercise training did not afford overweight/obese males additional health benefits, with the exception of improvements in fitness and hepatic IRI.

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Created

Date Created
  • 2016

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Body composition and physical activity maintenance one year after a 12-week exercise intervention in women

Description

Purpose: Exercise interventions often result in less than predicted weight loss or even weight gain in some individuals, with over half of the weight that is lost often being regained

Purpose: Exercise interventions often result in less than predicted weight loss or even weight gain in some individuals, with over half of the weight that is lost often being regained within one year. The current study hypothesized that one year following a 12-week supervised exercise intervention, women who continued to exercise regularly but initially gained weight would lose the weight gained, reverting back to baseline with no restoration of set-point, or continue to lose weight if weight was initially lost. Conversely, those who discontinued purposeful exercise at the conclusion of the study were expected to continue to gain or regain weight. Methods: 24 women who completed the initial 12-week exercise intervention (90min/week of supervised treadmill walking at 70%VO2peak) participated in a follow-up study one year after the conclusion of the exercise intervention. Subjects underwent Dual-energy X-Ray Absorptiometry at baseline, 12-weeks, and 15 months, and filled out physical activity questionnaires at 15 months. Results: A considerable amount of heterogeneity was observed in body weight and fat mass changes among subjects, but there was no significant overall change in weight or fat mass from baseline to follow-up. 15 women were categorized as compensators and as a group gained weight (+ 0.94±3.26kg) and fat mass (+0.22±3.25kg) compared to the 9 non-compensators who lost body weight (-0.26±3.59kg) and had essentially no change in fat mass (+0.01±2.61kg) from 12-weeks to follow-up. There was a significant between group difference (p=.003) in change in fat mass from 12-weeks to follow-up between subjects who continued to regularly vigorously exercise (-2.205±3.070kg), and those who did not (+1.320±2.156kg). Additionally, energy compensation from baseline to 12-weeks and early body weight and composition changes during the intervention were moderate predictors of body weight and composition changes from baseline to follow-up. Conclusion: The main finding of this study is that following a 12-week supervised exercise intervention, women displayed a net loss of fat mass during the follow-up period if regular vigorous exercise was continued, regardless of whether they were classified as compensators or non-compensators during the initial intervention.

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Created

Date Created
  • 2013

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Omega-3 supplementation and body weight in healthy young women

Description

Objective: The purpose of this randomized parallel arm trial was to demonstrate the effects of daily fish oil supplementation (600mg per day for eight weeks) on body composition and body

Objective: The purpose of this randomized parallel arm trial was to demonstrate the effects of daily fish oil supplementation (600mg per day for eight weeks) on body composition and body mass in young healthy women, aged 18-38, at a large southwestern university. Design: 26 non-obese (mean BMI 23.7±0.6 kg/m2), healthy women (18-38y; mean, 23.5±1.1 y) from a southwestern Arizona university campus community completed the study. Subjects were healthy, non-smokers, consuming less than 3.5 oz of fish per week according to self-report. Participants were randomized to one of two groups: FISH (600 mg omega-3 fatty acids provided in one gel capsule per day), or CON (1000 mg coconut oil placebo provided in one gel capsule per day). Body weight, BMI, and percent body fat were measured using a stadiometer and bioelectrical impedance scale at the screening visit and intervention weeks 1, 4, and 8. 24-hour dietary recalls were also performed at weeks 1 and 8. Results: 8 weeks of omega-3 fatty acid supplementation did not significantly alter body weight (p=0.830), BMI (p=1.00), or body fat percentage (p=0.600) as compared to placebo. Although not statistically significant, 24-hour dietary recalls performed at the beginning and end of the intervention revealed a trend towards increased caloric intake in the FISH group and decreased caloric intake in the CON group throughout the course of the study (p=0.069). If maintained, this difference in caloric intake could have physiological relevance. Conclusions: Omega-3 fatty acids do not significantly alter body weight or body composition in healthy young females. These findings do not refute the current recommendations for Americans to consume at least 8 oz of omega-3-rich seafood per week, supplying 250 mg EPA and DHA per day. More research is needed to investigate the potential for omega-3 fatty acids to modulate daily caloric intake.

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Created

Date Created
  • 2013

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The relationship of fat mass to lower body muscular fitness using isokinetic measures in young and middle-age women

Description

Larger people generally have more muscle mass and are stronger than smaller people. Muscular strength usually decreases with age, possibly as a function of increases in body fat percentage. However,

Larger people generally have more muscle mass and are stronger than smaller people. Muscular strength usually decreases with age, possibly as a function of increases in body fat percentage. However, the effect of age, body fat, and lean mass on peak muscular strength or muscular fatigue is not clear. This was an observational study to determine: a) the relationship of fat mass (FM) and fat free mass (FFM) to peak knee extensor strength and fatigue in young (Y) and middle-aged (MA) women, and b) to determine differences in peak torque between Y and MA women. Participants included 132 women from two age cohorts (Y: 18-33 yrs, n = 70 and MA: 45-65 yrs, n = 62). Data from the MA cohort were collected as part of a previous study and combined with data from the Y group. Both cohorts completed physical activity questionnaires and were measured for body fat using bioelectrical impedance analysis. Both cohorts used identical procedures and machinery to assess isokinetic knee extensor peak torque (PT) at 60°/sec and to determine fatigue index (FI). FI was calculated as the percent decline of PT during 50 maximal repetitions at 240°/sec. Data were assessed for normality, and appropriate Pearson or Spearman correlations were used to compare PT and FI with body composition variables. A one-way ANOVA was used to examine differences in PT and body composition indices between age groups. In Y, FFM and FM were strongly correlated with peak torque. The correlation of FM to PT disappeared when controlling for FFM. There were no significant correlations between FFM or FM and PT in MA. PT was negatively correlated with FI in the combined groups. PT normalized for body mass and FFM were similar between age groups, but decreased with increasing size. In conclusion, PT was positively related to FFM in the combined age groups. Higher FM was not detrimental to absolute PT in Y or MA, but was detrimental to relative PT in both groups. These data suggest that perhaps FM may attenuate the normal relationship between PT and body mass.

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Agent

Created

Date Created
  • 2011