Walden University ScholarWorks Walden Dissertations and Doctoral Studies Walden Dissertations and Doctoral Studies Collection 2018 Relationship Between Exposure to Phthalate and Obesity in the United States Gladys Chidiebere Ezem Walden University Follow this and additional works at: https://scholarworks.waldenu.edu/dissertations Part of the American Studies Commons, Environmental Health and Protection Commons, and the Epidemiology Commons This Dissertation is brought to you for free and open access by the Walden Dissertations and Doctoral Studies Collection at ScholarWorks. It has been accepted for inclusion in Walden Dissertations and Doctoral Studies by an authorized administrator of ScholarWorks. For more information, please contact [email protected]. Walden University College of Health Sciences This is to certify that the doctoral dissertation by Gladys Ezem has been found to be complete and satisfactory in all respects, and that any and all revisions required by the review committee have been made. Review Committee Dr. Nicoletta Alexander, Committee Chairperson, Public Health Faculty Dr. Scott McDoniel, Committee Member, Public Health Faculty Dr. Diana Naser, University Reviewer, Public Health Faculty Chief Academic Officer Eric Riedel, Ph.D. Walden University November 2018 Abstract Relationship Between Exposure to Phthalate and Obesity in the United States by Gladys Ezem M. S. N., University of Phoenix, 2011 B.S.N., Imo State University, 2002 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public Health Walden University November 2018 Abstract Obesity is a public health problem. The global obesity problem has been attributed to unhealthy diet, inactivity, and hereditary factors. However, phthalates may also contribute to the obesity epidemic. The purpose of this cross-sectional study was to examine whether there was a relationship between exposure to phthalates and obesity among adults 18 years and older in the United States. The theoretical framework was based on the socioecological model. The quantitative, cross-sectional design, and data analysis were based on the National Health and Nutrition Examination Survey, 2011- 2012 database. Descriptive statistics and multiple regression analysis were used to analyze the association between phthalates, obesity, and other independent variables (phthalates exposure, socioeconomic status, gender, age, race/ethnicity, physical activity and place of residence) According to study results, exposure to phthalates does not have a statistically significant effect on the odds of obesity. In terms of the influence of the sociodemographic variables such as race, age, and gender on the relationship between total phthalate exposure and obesity, only race showed statistical significance at p < 0.05. In addition, physical activity did not have influence on relationship between total phthalate exposure and obesity among adults 18 years and older in the United States. Despite the lack of significant relationships, the results of this study are useful in addressing the concerns about the exacerbation of obesity. The results of this study could enhance academic research by showing the effect of phthalate chemical exposure, age, gender, race/ethnicity, physical activity, income, and educational level on obesity. Relationship Between Exposure to Phthalate and Obesity in the United States by Gladys Ezem M.S. N., University of phoenix, 2011 B.S.N., Imo state University, 2002 Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Public Health Walden University November 2018 Dedication I dedicate this dissertation to my God, my family, and my friends for their constant support and unconditional love. I love you all dearly. Acknowledgments My first gratitude goes to my God who granted me his grace to complete this Course. Despite him, I am northing. I would like to express my sincere gratitude to my Chair, Dr. Nicoletta, Alexander, for her continuous support, for her patience, motivation, and immense knowledge. Her guidance helped me in all the time of research and writing of this dissertation. I could not have imagined having a better chair for my Ph.D. study. Besides my chair, I would like to thank my dissertation committee members: Dr. Scott, McDoniel and Dr. Diana Naser for their insightful comments and encouragements. I also thank my friends and family members (too many to list here but you know who you are!) for providing support and friendship that I needed. I would like to thank Dr. Emmanuel Salawu, Dr. Edward Irobi, and Dr. Adaku Madubuko for being supportive throughout my time here and for helping me with proofreading my papers. I especially thank my mom, dad, sisters, and brothers. My hard-working parents have sacrificed their lives for my survival and provided unconditional love and care. I love them so much, and I would not have made it this far without them. I know I always have my family to count on when times are rough. I thank my beloved sons and daughters, Juliet Ezem, Justice Ezem, Augusta Ezem, and Victor Ezem, who stood by me during the rainy days. God reward you for all your efforts. Table of Contents Background of the Study .................................................................................................... 2 Obesity Level Increase Tendency ....................................................................................... 3 Overview of Obesity ........................................................................................................... 3 The Gap in Knowledge ........................................................................................................4 Problem Statement ...............................................................................................................5 Purpose of the Study ............................................................................................................7 Research Questions and Hypotheses ...................................................................................7 Definitions .........................................................................................................................11 Assumptions .......................................................................................................................12 Biases .................................................................................................................................14 Significance........................................................................................................................15 Summary ............................................................................................................................15 Chapter 2: Literature Review .............................................................................................17 Literature Search Strategy..................................................................................................18 Synopsis of the Current Literature on the Relevance of the Problem ................................18 Theoretical Foundation ......................................................................................................21 Individual .......................................................................................................................... 23 Association ........................................................................................................................ 23 District............................................................................................................................... 23 Community ....................................................................................................................... 24 i Literature Review Related to Key Variables and Concepts ...............................................24 Obesity .............................................................................................................................. 24 Chapter 3: Research Method ..............................................................................................45 Research Design and Rationale .........................................................................................45 Study Variables ................................................................................................................. 45 Research Design................................................................................................................ 46 Methodology ......................................................................................................................48 Population and Setting ...................................................................................................... 48 Sampling and Sampling Procedure ................................................................................... 49 Sampling Frame ................................................................................................................ 49 Sample Size and Power Analysis ...................................................................................... 50 Justification for the Effect Size ......................................................................................... 51 Research Design................................................................................................................ 51 Study Participants and Informed Consents ......................................................................