Abstract

Over the past few decades it has become apparent that increased body weight, specifically body fat, coupled with a sedentary lifestyle is associated with an increased risk for chronic disorders such as cardiovascular disease and diabetes. Researchers are now re-directing their focus on determining the cause of these relationships from an epidemiological view to a more biological or physiological standpoint. The purpose of this cross sectional study was to examine associations among obesity, physical activity and select immune, endocrine and metabolic parameters identified as risk factors for several chronic conditions. Ninety-one healthy males between the ages of 19 and 45 volunteered for this study. Anthropometric measures included height, weight, waist and hip circumference, and percentage body fat, assessed by seven site skin-folds. Physical activity data were collected on a self report questionnaire and was compared to the levels suggested by the US Surgeon General. The endocrine, metabolic and immune parameters measured were: lipid profiles, fasting blood glucose, cortisol, white blood cell count and differentials, and lymphocyte proliferation. Percentage body fat was significantly related to a deterioration in the lipid profile as represented by an increase in both very low density lipoproteins (r = 0.405, p<0.0008) and a decrease in the ratio of high density cholesterol to total cholesterol (r = 0.469, p<0.0008). White blood cell count was more strongly related to fat mass (r = 0.35, p<0.005) and percentage body fat (r = 0.35, p<0.005) than BMI (r = 0.25, p<0.05) In addition, those who reported participating in physical activity at or above the level suggested by the surgeon general had smaller waist to hip ratios, lower percentage body fat, fat mass and more favorable lipid profiles (p<0.05). This study demonstrated the necessity to further evaluate the accuracy of using BMI as an indicator of obesity or chronic health risk in an adult male population. Future investigations concerning obesity and morbidity and mortality should include measurements of body composition and/or body fat distribution. Additionally, the results of this study are in agreement with the latest US Surgeon General recommendations of the positive health benefits of regular participation in physical activity. However, further investigation is necessary to determine the optimal level of physical activity. Based on the results of this study, medical professionals, preventive care specialist and allied health professionals are encouraged to obtain measurements of body composition in addition to using BMI when assessing chronic disease risk in their patients.

School

School of Public Health

First Advisor

Helen Hopp Marshak

Second Advisor

Bryan Haddock

Third Advisor

Lora Green

Degree Name

Doctor of Public Health (DrPH)

Degree Level

Ph.D.

Year Degree Awarded

2002

Date (Title Page)

8-2002

Language

English

Library of Congress/MESH Subject Headings

Body Composition -- physiology; Male; Obesity -- physiopathology; Risk Factor; Exercise; Anthropometry -- methods; Bodymass Index; Body Weight -- physiology; Adult.

Type

Dissertation

Page Count

xi; 111

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

Download

Share

COinS