Factors Affecting Nutritional Status and Eating Behaviours of Adolescent Girls in Saudi Arabia
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Factors affecting nutritional status and eating behaviours of adolescent girls in Saudi Arabia Elham AL-Jaaly Thesis submitted for the degree of DOCTOR OF PHILOSOPHY University College London Centre for International Health and Development Institute of Child Health UCL August 2012 Declaration I, Elham Al-Jaaly, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated. Signed: ELham Al-Jaaly August 2012 2 Abstract The objective of this study was to assess factors affecting nutritional status and eating behaviours among adolescent girls in Jeddah, Saudi Arabia. A cross-sectional survey was conducted in 1519 13 to 18-year-old girls from 18 schools. Nutritional assessment included anthropometric, haemoglobin measurements, and a questionnaire exploring a range of nutrition-related issues. Since one of the major influences on eating behaviours is food marketing and media, a descriptive analysis of TV advertisements aired on three of the most popular TV channels was carried out. In addition, analysis of the content of school meals was conducted. The overall prevalence of overweight girls is 24% of the population, obesity 13.5% and underweight 14%. The prevalence of anaemia (Hb<12 g/dl) was 29%. Some eating behaviours were found to be particularly prevalent, including snack consumption, eating outside the home, consumption of sugar-carbonated drinks, and very low consumption of vegetables and fruit. The media was regarded as one of the most important sources of health information. The analysis of the sampled advertisements (n=6,272) showed that of the entire number of paid product advertisements, (n=5150) 17.6% were for food and drink products. Of the total 1106 food and drink advertisements, 49% were for high-fat salt and sugar (HFSS) products. School meals were found to have very high HFSS content. This is the first in-depth study of factors affecting eating behaviours and nutrition status of adolescent girls who was guided by a theoretical framework. The study revealed that all aspects of the girls’ environment, including home, schools and community combined to promote unhealthy eating behaviours and lifestyle. This could have an impact on their diets, long-term health outcomes and therefore, warrant further evaluation. Results also emphasized the central role and obligation of decision makers in protecting young consumers through providing a healthy environment in home, community and schools. In addition, through tightening legislation and controlling media contents (particularly food advertising) that are targeting young people. It is anticipated that the findings of this research will serve as an impetus for planning appropriate nutrition intervention programmes for Saudi adolescent girls. 3 Content pages Title page 01 Declaration 02 Abstract 03 Contents pages O4 List of Tables 12 List of Figures 15 List of Appendices 17 Acknowledgements 19 Dedication 22 Abbreviations 23 Chapter One: Introduction 24 1.1 Purpose of the Study 24 1.2 Progression and Organization of the Thesis 24 1.3 Definitions and explanation of Terms 25 1.4 General Introduction 27 1.5 Research Rationale 33 1.6 Aims & Objectives 36 Chapter Two: Literature Review and Conceptual Framework 37 2.1. Chapter introduction 37 2.2. Methodology of literature Review 38 2.2.1. Search strategies 38 2.3 Nutrition issues in adolescence 39 2.4 Weight status of adolescents, determinants and complications 41 2.4.1. Definitions of weight status 41 2.4.2. Trends of changes in weight status of Saudi adolescents 42 2.4.3. Obesity and associated risk factors 43 2.4.3.1. Causes of obesity 43 2.4.3.2. Risk factors for obesity 44 2.4.3.3. The tracking of risk factors related to obesity through life 45 4 2.4.4. Prevalence of overweight and obesity among Saudi 45 adolescents and contributing factors 2.4.4.1. Prevalence of overweight status & obesity among 45 Saudi adolescents 2.4.4.2. Contributing factors to overweight status & obesity 47 of Saudi adolescents 2.5 Iron-deficiency anaemia in adolescents 48 2.5.1. Iron needs during adolescence 49 2.5.2. Assessment of iron status 50 2.5.3. Epidemiology and risk factors of adolescents’ anaemia 50 in Saudi Arabia 2.6 Growth and development status 51 2.6.1. Patterns of growth 52 2.6.2. Assessment of nutritional status in adolescents 52 2.6.3. Anthropometric measurements and indices 52 2.6.3.1. Body composition 55 2.6.3.2. Biochemical Assessment 56 2.6.4. Growth, development and assessment of nutritional 57 status of Saudi adolescents 2.6.5. Dietary assessment 58 2.6.5.1. Food intake, eating behaviours and lifestyle of 58 adolescents 2.6.5.2. Food intake, eating behaviours and lifestyle of 62 Saudi adolescents 5 2.7 School meals and nutrition education 65 2.7.1. School meals and nutrition education in Saudi Arabia 67 2.8 Media, food marketing and advertising 68 2.8.1. Media in Saudi Arabia 68 2.8.2. Food promotion and marketing & Saudi adolescent 68 consumers 2.8.3. Television viewing and food adverts’ exposure 70 2.8.4. The effects of food promotion on children’s and 71 adolescents’ behaviour 2.8.5. Regulations and concerns about the effects of 74 television advertising on children 2.9 Theoretical Framework 84 2.9.1. Overview of Model 86 Chapter Three: Methods for Cross Section Survey 89 3.1 Chapter introduction 89 3.1.1. General methods for the survey 90 3.1.2. Study site 91 3.1.3. Sampling methods 92 3.1.3.1 Subjects, recruitments and recruitment criteria 94 3.1.4. Informed consent 96 3.1.5. Data management and confidentiality (protection) 96 3.1.6. Preliminary studies 96 3.1.6.1. The development of the questionnaire 96 3.1.6.2. The pilot study 100 3.1.7. Validity of the study’s questionnaire 101 3.1.7.1 Testing of the questionnaire at study site 102 6 3.1.8. Recruitment and training of field Staff 103 3.1.9. Data collection procedure 103 3.1.10. Assessment of nutrition status 104 3.1.10.1. Questionnaire data 104 3.1.10.2. Measurements 104 3.2 Measures 110 3.2.1. Outcome Measures 110 3.2.1.1 The first outcome measure (BMI) 111 3.2.1.2. The outcome measures related to WC & WHTR status 111 3.2.1.3. Anaemia status 111 3.2.1.4. School type 111 3.2.1.5. The media and its influence on food choice 112 3.2.2. Explanatory measures 112 3.2.2.1. Individual variables (intrapersonal) 112 3.2.2.2. Socio-environmental factors 122 3.3 Assessment of school meals, snacks and beverages 123 3.3.1. Information of school snacks and beverages 123 3.4 Data analyses 124 3.4.1. Objective Ia: Description of anthropometric profile included, weight, height, waist circumference and 125 haemoglobin levels 3.4.2. Objective Ib: Describing personal and environmental 125 characteristics of participants 3.4.3. Objective II: Associations of nutritional status with personal and environmental factors based on weight status, 125 WC and WHtR 3.4.4. Objective III: Assessing of school ‘meal menu and snack food options’ prepared and served by the caterer in 126 public schools 3.4.5. Objective IV: Differences in personal and 127 environmental factors according to school type 7 3.4.6. Objective V: Personal and environmental factors and associations with media (screen time and media influences 127 on food choice) Chapter Four: Survey Results 133 4.1 Chapter introduction 133 4.2 Characteristics of Jeddah adolescents’ girls 134 4.2.1. Socio-demographic characteristics of the sample 134 4.2.2. Anthropometry profile of Jeddah adolescent girls 136 4.2.3. Description of weight status of participants 137 4.2.3.1. Body Mass Index (BMI percentiles) 137 4.2.4. Description of centralized fat status of participants 141 4.2.4.1Waist circumference percentiles (WC) & waist-to-height ratio 141 (WHtR) 4.2.5. Biological and health status 144 4.2.6. Knowledge, attitudes and perceptions of health and figures 144 4.2.7. Food consumption, behaviours, and lifestyle 147 4.2.8. Dieting practices 147 4.2.9. Physical activities 149 4.2.10. Social environment 149 4.2.10.1. Physical environment 150 4.3 Main outcome Ia (BMI) 150 4.3.1. Associations between BMI categories and factors 150 influencing nutritional status 4.3.1.1. Individual factors 150 4.3.1.2. Environmental factors 151 4.4 Main outcome Ib (BMI) 158 4.4.1. BMI Z-scores 158 4.2.4.2. Correlations between BMI Z-scores and Personal and 158 Environmental Factors 4.2.4.2.1. Personal factors 158 8 4.2.4.2.2. Environmental factors 163 4.5 Main outcome IIa (WC): WC at a cut-off of ≥75th 166 4.5.1. Associations of centralized fat status with other factors 166 influencing the nutritional status of participants 4.5.1.1. Associations between body fatness (WC) and weight 166 status 4.5.1.2. Associations between WC and other factors 166 4.6 Main outcome IIb (WHtR): Waist-to-height Ratio at a cut-off of 0.5 168 4.6.1. Associations between WHtR and weight status categories 168 4.6.2. Associations between body fatness (WHtR) and other Factors 169 4.7 Main outcome III (Anaemia) 172 4.7.1. Anaemia status and related determinants 172 4.7.1.1. Prevalence of anaemia defined by haemoglobin (HB) level 172 4.8 Main outcome IV (School meals) 176 4.8.1.