Date of Award

Summer 6-23-2014

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Nutrition

First Advisor

Anita Nucci, PhD, RD, LD

Second Advisor

Sarah Henes, PhD, RD, LD

Third Advisor

Catherine McCarroll, MPH, RD, LD

Abstract

ABSTRACT

ASSOCIATION OF ANTIOXIDANT INTAKE AND BODY MASS INDEX IN

PRE-TO-EARLY ADOLESCENT CHILDREN

by

E. Kelly Imboden

Background: The prevalence of overweight (Body Mass Index [BMI]85-<95th percentile) and obesity (BMI>95thpercentile) for individuals aged 2-19 years in the United States in 2009-2010 was estimated to be 31.8%. Excessive body fat increases the risk for chronic conditions such as hypertension and type 2 diabetes mellitus. Studies have established an association between obesity and oxidative stress and inflammation in children and adolescents. Antioxidants have been shown to have protective effects against inflammation and oxidative stress. However, the effect of dietary antioxidant intake on obesity is not fully understood.

Objective: To examine dietary antioxidant intake by BMI classification in a population of normal, overweight and obese children.

Methods: The study population included 296 healthy pre-to-early adolescent (age 6-15 years) African American and Caucasian children residing in Pittsburgh, PA. Demographic characteristics, anthropometric measures and nutrient intake were assessed at baseline and six months. A food frequency questionnaire was used to assess antioxidant intake (vitamin C, carotene, total vitamin A, zinc and vitamin E). Frequency analysis was used to describe demographic, anthropometric and nutrient data. The Kruskal Wallis test was used to evaluate difference in median antioxidant and kilocalorie intake by BMI classification at baseline. A Kendall’s tau correlation was performed to test for a linear relationship between BMI and antioxidant intake at baseline.

Results: The median age of the population was 10 years (range, 8 to 11 years). The majority of the population was male (53%) and African American (60%). Weight and BMI (p = 0.028 and 0.000, respectively) were the only demographic and anthropometric characteristics that differed by gender. For the total cohort, median nutrient intake by BMI classification was significantly different for vitamin C (p = 0.015), zinc (p = 0.019), vitamin E (p = 0.022) and kilocalories (p = 0.015). When divided by gender, zinc intake in males (p = 0.047) and kilocalorie intake in females (p = 0.017) were the only nutrients found to be statistically different by weight classification. No linear relationship was observed between antioxidant intake and BMI for the total cohort and for each gender.

Conclusion: Our results do not support a linear relationship between antioxidant intake and BMI. In contrast to our hypothesis, antioxidant intake was found to be highest in children who were overweight. Future studies should include a serum measure of inflammation and antioxidant levels in addition to antioxidant intake to better understand the impact, if any, of antioxidants in overweight and obese children and adolescents.

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