Obesity and Psychological Distress in Young Adults

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Co-supervision thesis For the degree of Doctor Université Libre de Buxelles

School of Public Health And

Lebanese University

Doctoral School of Sciences and Technology Speciality: Public Health, Epidemiology

Presented by

ABOU ABBAS Linda

Obesity and Psychological Distress in Young Adults

Thesis Director (Belgium) : Prof. GODIN Isabelle Thesis Director (Lebanon): Prof. SALAMEH Pascale

Defensed on December 22, 2015

Jury Members

Mrs. Godin Isabelle, Professor - Université Libre de Bruxelles Director Mrs. Salameh Pascale, Professor - Lebanese University Director Mr. Dimassi Hani, Associate Professor - Lebanese American University Reviewer Mrs. Robert Annie, Professor- Université Catholique de Louvain Reviewer Mr.Donnen Philippe, Professor - Université Libre de Bruxelles Examiner

Mrs. Saleh Nadine, Professor- Lebanese University Examiner

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TABLE OF CONTENT

LIST OF FIGURES...iv

LIST OF TABLES...v

DEDICATION...vi

ACKNOWLEDGEMENTS...vii

ABSTRACT...ix

RESUME...xi

LIST OF ORIGINAL PAPERS...xiii

LIST OF ABBREVIATIONS...xiv

THESIS STRUCTURE...xv

CHAPTER 1 INTRODUCTION...1

CHAPTER 2 LITERATURE REVIEW...7

2.1 The psychological impact of obesity...7

2.2 Body image...11

2.2.1 Definition of Body image concept...11

2.2.2 Body image assessment in obese adults...11

2.2.3 Body image dissatisfaction and its associated factors...12

2.3 Plausible mechanisms for the association between obesity and PD...15

2.3.1 Biological mechanisms...15

2.3.2 Psychosocial mechanisms...16

2.4 Summary of Findings...17

CHAPTER 3 STUDY AIMS AND HYPOTHESES...19

3.1 General aims...19

3.2 Specific aims and hypotheses...19

3.2.1 Exploring the association between obesity and psychological health in the Middle East and particularly Lebanon...19

3.2.2 Development and validation of a scale for PD assessment in the obese adult population...20

3.3 Significance of the Research...21

CHAPTER 4 METHODS...22

4.1 Overview...22

4.2 Obesity and depression among Adults in the Middle East...23

4.2.1 Search strategy...23

4.2.2 Selection criteria...23

4.2.3 Data extraction and synthesis...24

4.2.4 Methodological quality assessment...24

4.2.5 Statistical analysis...25

4.3 Body Mass Index and Psychological Distress among Lebanese University students...26

4.3.1 Study design and participants...26

4.3.2 Data collection...27

4.3.3 Statistical analyses...29

4.4 Body image dissatisfaction and Psychological Distress among Obese Young Adults in Lebanon...30

4.4.2 Study measurements...31

4.5 Development and initial Validation of a Brief Scale for Assessing Psychological Distress in Obese Young Adults...32

4.5.1 Item generation and development of the OSD questionnaire...32

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4.5.2 Content validity...33

4.5.3 Pilot study...33

4.5.4 Sample size calculation...34

4.5.5 Procedure...35

4.5.6 Assessment Measures...35

CHAPTER 5 RESULTS...38

5.1 Obesity and Depression among Adults in the Middle East...38

5.1.1 Study selection strategy...38

5.1.2 Study characteristics...38

5.1.3 Quality assessment...39

5.1.4 Meta-analysis of association between obesity and depression...41

5.1.5 Subgroup and sensitivity analysis...42

5.1.6 Publication bias...43

5.2 Body Mass Index and Psychological Distress among Lebanese University students...44

5.2.1 Characteristics of the study sample...44

5.2.2 Bivariate analysis of the BDS-22...45

5.2.3 Multivariate analysis of the association between BDS-22 and BMI categories...46

5.3 Body image dissatisfaction and Psychological Distress among Obese Young Adults in Lebanon...50

5.3.1 Characteristics of the study sample...50

5.3.2 Reliability of the questionnaires...50

5.3.3 Psychological Distress, Body image dissatisfaction and Eating disorders in the overall sample and stratified by gender...51

5.3.4 Correlational analysis between BDS-22, BMI and BSQ-16 in the overall study sample and by gender ...52

5.3.5 Multiple Regression Analyses...53

5.4 Development and Initial Validation of a Brief Scale for Assessing Psychological Distress in Obese Young Adults...54

5.4.1 Samples characteristics...54

5.4.2 Exploratory Factor analysis...55

5.4.3 Confirmatory factor analysis...56

5.4.4 Internal consistency...57

5.4.5 Test-retest reliability...58

5.4.6 Construct validity...58

5.4.7 Discriminant validity...59

5.4.8 Correlations of the OSD scores with BMI...59

CHAPTER 6 DISCUSSION...62

5.1 Synopsis of the main findings...62

5.2 Strengths and limitations of the research studies...67

5.3 Future directions...71

Chapter 7 Conclusions...73

7.1 Summary of major findings...73

7.2 Implications for public health and clinical practices...74

7.3 General Conclusion...76

REFERENCES...77

ANNEXES...94

Annex 1 Arabic version of the Obesity Specific Distress scale...95

Annex 2 English version of the Obesity Specific Distress scale...96

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