Date of Graduation

5-2019

Document Type

Thesis

Degree Name

Bachelor of Science

Degree Level

Undergraduate

Department

Health, Human Performance and Recreation

Advisor/Mentor

Howie, Erin

Committee Member/Reader

Gray, Michelle

Committee Member/Second Reader

Walker, Kate

Abstract

Background: Due to the obesity epidemic, many studies have compared nutrient intake to human body composition. However, previous studies have not used gold standard measures of body composition in a college population. Purpose: The purpose of this study is to examine how dietary behaviors, overall energy intake, and macronutrient intake are associated with the body composition factors measured in a dual-energy x-ray absorptiometry (DXA) scan. We hypothesize higher body fat percentage will be associated with higher fat and carbohydrate intake, but not total energy intake. Methodology: This was a cross-sectional study done as part of Exercise is Medicine® On Campus initiative. It was a convenience sample of subjects that had to be connected to the University of Arkansas as a student, faculty, or a staff member, and at least 18 years old. Body composition was measured using a DXA scan, which measured total body lean tissue, fat mass, and bone mineral density. Participants completed an online survey on dietary habits. 24-hour dietary recalls will be used to determine nutrient intake for each subject. Results from the recalls will be entered into Nutritionist Pro™ to obtain macronutrient levels and overall energy intake. Descriptive statistics were calculated and linear regression adjusted for sex and age compared the dependent variables of body composition by independent variables of dietary behaviors. Results: Survey: There were a total of 47 participants (n=29 women), with a mean age of 29.2 (SD 12.5, range 19.1 to 66.0). Preliminary results found average percent body fat of 33.9% (SD 8.6) for women and 21.8% (SD 7.3) for men, lean mass of 39.5 kg (6.2) for women and 59.0 kg (5.8) for men, bone mineral density of 1.2 (0.1) for women and 1.3 (0.1) for men. Eight participants (17%) drank milk at least daily and of those that consumed milk at all, 11 (26.2%) primarily consumed whole milk. Additionally, 19 (41%) participants consumed fruit at least daily. In models adjusted for age and sex, there were no differences in percent body fat (β 2.5, p=.435), lean mass (β 0.6, p=.806), or bone mineral density (β .004, p=.925) in those who consumed milk daily compared to those who consumed milk less than daily. There was no difference in percent body fat (β 2.3, p=.368) between those who consumed fruit daily compared to those who consumed less than one serving of fruit daily. Dietary Recalls and DXA: there was no association between total fat percentage and total energy intake (β 0.1, p=.124), carbohydrate intake (β=-0.1, p=.268), protein intake (β=0.1, p=.637), or fat intake (β=0.1, p=.439). The same is true for android fat percentage, gynoid fat percentage, and lean mass percentage. There was an association between total energy (Kcal) intake and bone mineral density (β=.002, p=.039). Bone mineral density was not associated with carbohydrate intake (β=0.0, p=.979), protein intake (β=-.003, p=.089), or fat intake (β=.002, p=.092). Discussion: Results from the survey indicate that there is not an association between body composition and dietary behaviors. Results from dietary recalls indicate there is no association between body composition and macronutrients, but there is an association between bone mineral density and total energy intake. Further studies for combatting the epidemic of obesity should also look at other behaviors such as exercise and lifestyle.

Keywords

body composition, DXA, obesity, macronutrients, nutrition, college population

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