LOSING WEIGHT AND EATING DISORDER RISK: THE ROLE OF DIET TYPE, DIETING STRATEGIES, BMI, AND PSYCHOLOGICAL FACTORS IN ACHIEVING WEIGHT LOSS AND INCREASING EATING DISORDER RISK By OLESYA VLADIMIROVNA MIKHEEVA A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE UNIVERSITY Department of Psychology JULY 2019 © Copyright by OLESYA VLADIMIROVNA MIKHEEVA, 2019 All Rights Reserved © Copyright by OLESYA VLADIMIROVNA MIKHEEVA, 2019 All Rights Reserved To the Faculty of Washington State University: The members of the Committee appointed to examine the dissertation of OLESYA VLADIMIROVNA MIKHEEVA find it satisfactory and recommend that it be accepted. Sarah Tragesser, Ph.D., Chair Paul Kwon, Ph.D. Paul Strand, Ph.D. ii ACKNOWLEDGMENT I would like to thank Sarah Tragesser for her support and education throughout my graduate training and for her guidance in creating this project. I also extend my thanks to Eric Desmarais for his assistance as a statistics consultant and his support throughout this project. Finally, I thank Jacob Mussman for his constant support throughout this process. iii LOSING WEIGHT AND EATING DISORDER RISK: THE ROLE OF DIET TYPE, DIETING STRATEGIES, BMI, AND PSYCHOLOGICAL FACTORS IN ACHIEVING WEIGHT LOSS AND INCREASING EATING DISORDER RISK Abstract by Olesya Vladimirovna Mikheeva, Ph.D. Washington State University July 2019 Chair: Sarah Tragesser Although research has investigated various weight loss strategies among those with obesity, and the link between a desire to lose weight and eating disorders is well known, research focused on understanding how dieting attempts increase eating disorder risk is almost completely lacking. The present study was the first to examine these constructs simultaneously to determine how psychological factors, dieting strategies, type of diet, and BMI contribute to weight loss and/or eating disorder risk. College students (n=918) answered a series of online questionnaires assessing dieting habits, psychological traits, and disordered eating. Results indicated that type of diet and dieting strategy was only a risk factor for some individuals, depending on other psychological and physical risk factors. Results point to the importance of dieting motives, dieting strategies, and psychological factors that combine with type of diet and BMI to put individuals at eating disorder risk. Findings also indicate which type of diet or dieting strategies can help individuals reach their weight loss goals without creating risk for eating disorders. Furthermore, results demonstrate which factors only contribute to eating disorder risk, only promote or hinder weight loss, or impact both eating disorder risk and weight loss. The present study highlights psychological factors that can be used in interventions when attempting to treat or prevent eating disorders, according to one’s current weight category. iv TABLE OF CONTENTS Page ACKNOWLEDGMENT ........................................................................................................... iii ABSTRACT .............................................................................................................................. iv LIST OF TABLES ..................................................................................................................... ix CHAPTERS CHAPTER ONE: INTRODUCTION .............................................................................. 1 Obesity and Eating Disorders ..................................................................................... 1 Diets .......................................................................................................................... 3 Diet Plans ............................................................................................................. 4 Pre-packaged meal diets ................................................................................... 4 Balanced restriction diets ................................................................................. 5 Self-monitoring diets ........................................................................................ 6 Vegetarian diets ............................................................................................... 7 Low carbohydrate and low fat diets .................................................................. 8 Meal replacement diets ..................................................................................... 9 Very-low-calorie diets .................................................................................... 11 Cycling diets .................................................................................................. 13 Comparing the effectiveness of diet programs ................................................ 13 Diets and Risk for Eating Disorders .................................................................... 14 Low Risk ....................................................................................................... 15 Moderate Risk ................................................................................................ 16 High Risk ....................................................................................................... 18 Summary of Diets and Eating Disorder Risk ....................................................... 20 v Dieting Strategies .................................................................................................... 20 Dieting Strategies and Weight Loss ..................................................................... 20 Dieting Strategies and Eating Disorder Risk ........................................................ 23 Psychological Factors .............................................................................................. 24 Psychological Factors and Weight Loss .............................................................. 24 Psychological Factors and Eating Disorder Risk.................................................. 27 The Present Study .................................................................................................... 29 CHAPTER TWO: METHODOLOGY ........................................................................... 32 Participants .............................................................................................................. 32 Measures ................................................................................................................. 32 Demographics Information .................................................................................. 32 Weight Loss ........................................................................................................ 33 Diets ................................................................................................................... 33 Dieting Strategies ................................................................................................ 33 Eating Behavior .................................................................................................. 34 Eating Disorder Risk ........................................................................................... 34 Motivation for Dieting ........................................................................................ 34 Dichotomous Thinking........................................................................................ 35 Negative Urgency ............................................................................................... 35 Coping ................................................................................................................ 35 CHAPTER THREE: RESULTS .................................................................................... 37 Analyses .................................................................................................................. 37 Preliminary Analyses .......................................................................................... 37 vi Eating Disorder Risk ........................................................................................... 38 Weight Loss ........................................................................................................ 39 CHAPTER FOUR: DISCUSSION................................................................................. 41 Eating Disorder Risk ................................................................................................ 41 Diet Type ............................................................................................................ 41 BMI .................................................................................................................... 43 Psychological Risk Factors ................................................................................. 44 Weight Loss ............................................................................................................. 45 Diet Type ............................................................................................................ 45 BMI .................................................................................................................... 46 Dieting Strategies and Psychological Factors ...................................................... 46 Eating Disorder Risk and Weight Loss ..................................................................... 48 Implications ............................................................................................................