Prevalence and Social Determinants of Overweight and Obesity in Adolescents in Saudi Arabia: a Systematic Review

Prevalence and Social Determinants of Overweight and Obesity in Adolescents in Saudi Arabia: a systematic review

Reem Mohd A. Habbab

A thesis submitted in in conformity with the requirements for the degree of MSc – Nutritional Sciences Department of Nutritional Sciences University of Toronto

Prevalence and Social Determinants of Overweight and Obesity in Adolescents in Saudi Arabia: a systematic review

Reem Habbab

Master’s degree – Nutritional Sciences

Department of Nutritional Sciences University of Toronto

2019

Abstract

Background: The prevalence of obesity in adolescents is increasing globally at an alarming rate. Objectives: Our aim was to evaluate the prevalence of overweight and obesity (Ow/Ob) in Saudi adolescents and to construct an ecological model of social determinants of Ow/Ob and evaluate current evidence of their effect on Saudi adolescents. Methods: A systematic review of literature reported up to 31/12/2018 on Ow/Ob and factors that can influence them in Saudi adolescents was conducted. Results: Fifty-one studies with n=97,666 adolescents

(56.9% males) were reviewed. The prevalence of Ow/Ob started off high and continued to increase over time. Most of the 49 reviewed social determinants reports, from 19 studies, showed positive association between social determinants and Ow/Ob in Saudi adolescents.

Conclusion: Adolescents’ Ow/Ob is a major public health problem in Saudi Arabia and is growing. Social determinants play a significant role in this problem and should be considered in all strategies targeting it.

Acknowledgments

My sincerest thanks and appreciation for the support and guidance of my supervisor Dr. Zulfiqar

Bhutta who spared time and effort to guide me through this program and provide me with all the advice and feedback I needed. Special thanks to Dr. John Sievenpiper and Dr. Thomas Wolever for their extremely valuable advice and feedback as my advisory committee members. Another special thanks to the administrative staff including Ms. Grace Belayneh and Ms. Louisa Kung that helped facilitate all processes required throughout this program. Also, my sincere thanks to the

Ministry of National Guard Health Affairs, KSA, for sponsoring my master’s degree and the Saudi

Arabian Cultural Bureau staff for the endless help and support at all levels. Finally, I would like to thank my parents for their unconditional love, support and inspiration that lead me here and for their guidance and motivation throughout this journey.

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Table of content Chapter 1

1 Introduction……………………………………………………………..………..…....1

1.1 Why obesity?...... 1

1.2 Why adolescents?...... 2

1.3 Why Saudi Arabia?...... 3

1.4 Why social determinants?...... 5 1.4.1 Individual lifestyle factors……………………………………...…... 6 1.4.2 Social and community network……………………………...…... 7 1.4.3 Living and working conditions……………………………...... ….. 8 1.4.4 General socioeconomic, cultural and environmental conditions………………………………………………………..…...…... 8

1.5 Social determinants of overweight and obesity in adolescents...... 10 1.5.1 Dietary habits (patterns/contents)…………………..……...…...10 1.5.2 Physical activity……………………………...... …...10 1.5.3 Sedentary behavior…………..…………………………….....…...11 1.5.4 Sleep patterns/Stress/Smoking…….…………………..…...…...11 1.5.5 Family history of obesity/Family size…….……………...... …...12 1.5.6 Household income…….………………..………………………...…...13 1.5.7 Parental education…….………………..………………………...…...13 1.5.8 Working mother...…….………………..………………………….…...14 1.5.9 Health/label literacy…….………………..……………………....…....14 1.5.10 School food/environment……..…..……………………….....…...14 1.5.11 Urbanization……..…..………………………...…………………….....15

1.6 Defining overweight and obesity in adolescents………....15 1.6.1 International Obesity Task Force system………………….... 15 1.6.2 Centers for Disease Control and Prevention system…... 15 1.6.3 World Health Organization system……………………………...16

1.7 Objectives………………………………………………………………………..16

Chapter 2

2 Methods……………………………………………………………………………...…. 17 2.1 Selecting Determinants of overweight and obesity relevant to Saudi adolescents ……………………………….……. 17

2.2 Protocol and Search strategy ……………………………………….18

2.3 Analysis………………………….……………………………………………...... 20

Chapter 3

3 Results………………………………………………………………………………..…. 23 3.1 Included studies……………………………………………….…………… 23

3.2 Study population…………………………………………………………… 24

3.3 Determining Overweight and Obesity…………………..……. 25

3.4 Prevalence Rates of Overweight and Obesity……….…. 25

3.4.1 Prevalence Rates of overweight and obesity from

national surveys……………………………………….………….……25

3.4.2 Prevalence Rates of overweight and obesity from regional

and multiregional studies………………………..……27

3.5 Social Determinants of overweight and obesity…….…. 29

3.5.1 Diet patterns/contents …………………………….………………..29 3.5.2 Physical activity ………..……………………………………………..31 3.5.3 Social media/Screen time ……….…………………...…………..33 3.5.4 sleep patterns/ Stress/smoking………….…………….………..35 3.5.5 Family size & Family history of obesity… …………….…….36 3.5.6 Economics/Household factors …………………...……………..37 3.5.7 Parental Educations ………………..……………………………....39 3.5.8 Working mother …………………………………………..…………..42 3.5.9 Label literacy/general education………………...……………..43

3.5.10 School/food environment …………………..……………….…..43 3.5.11 Urbanization ……………………………………..……………….…..44

Chapter 4

4 Discussion………………………………………………………………………….….. 45

4.1 Prevalence Rates………………………………………………………… 45 4.1.1 Prevalence Rates of overweight and obesity from national surveys……………….………………….…………….……45

4.1.2 Prevalence Rates of overweight and obesity from regional and multiregional studies ……….…………….……46

4.2 Social Determinant of overweight and obesity in adolescents………………………………………………………..………… 47

4.2.1 Identifying and constructing an ecological model….……47

4.2.2 Determinants of overweight and obesity in Saudi adolescents ……….…………………………………………….……48 4.2.2.1 Dietary habits (patterns/contents).…..……..…...…....48 4.2.2.2 Physical activity…………...... …...48 4.2.2.3 Sedentary behavior…………..……………………...... 49 4.2.2.4 Sleep patterns/Stress/Smoking…….………….....…...50 4.2.2.5 Family history of obesity/Family size…….…………..52 4.2.2.6 Household income…….………………..…………….…...53 4.2.2.7 Parental education…….………………..…………………53 4.2.2.8 Working mothers...…….………………..……………..…..54 4.2.2.9 Health literacy…….………………..………..…………...... 54 4.2.2.10 School/Food environment……..…..…………………..55 4.2.2.11 Urbanization……..…..……..……...……………………....55

4.3 Social Policy and Structural Measures ………………….... 56 4.3.1 Types of interventions to tackle obesity ……………….…..56

4.3.2 WHO Recommendations on policy action and interventions: ……………..………………………………….………..57

4.3.3 Relevant policies in Saudi Arabia…………………….………..60

4.4 Strengths and Limitations…………………………………….…….. 61 4.4.1 Strengths ………………………………………………..……..………..61

4.4.2 Limitations …………………………………………..…………………..61

4.5 Conclusions……………………………………..………………….….……. 62

References………………………………………………………….……….…………… 63

Appendices……………………………………………………………………...……..… 77

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List of Tables

Table 1. Comparison of the prevalence of Overweight and Obesity according to

BMI by sex in Saudi Arabia between 1975 and 2014……………………….…..….. 4

Table 2. Key variables data extraction form (see Appendix 1) ……………………..……….. 21

Table 3. Type of publication journals used in the review.……………………………..….…. 24

Table 4. Distribution (number & %) of subjects included the studies per region……….…. 24

Table 5. BMI reference standards used to define overweight and obesity in Saudi Arabian adolescents in the reviewed studies.………………………………………………… 26

Table 6. Yearly mean prevalence (%) rates standards used to define overweight and obesity in Saudi Arabian adolescents in the reviewed regional and multiregional studies.………………………………………………………………………………… 28

Table 7. Number of reviewed reports for each determinant of overweight and obesity… 29

Table 8-A. Fast food and soft drink intake and the prevalence (%) of overweight and obesity in Saudi adolescents.………………………………………………… 30

Table 8-B. skipping breakfast and vegetable intake and the prevalence (%) of overweight and obesity in Saudi adolescents.………………………….….…… 31

Table 9-A. Duration of physical activity and the prevalence (%) of overweight and obesity in Saudi adolescents ……………………………………………………. 32

Table 9-B. The practice of physical activity and the prevalence (%) of overweight and obesity in Saudi adolescents …………………………………………………….. 33

Table 10-A. TV/Computer screen time and the prevalence (%) of overweight and obesity in Saudi adolescents.…………………………………………………….... 34 viii

Table 10-B. TV/Computer screen time spent by Saudi adolescents in relation to body weight………………………………………………………………………… 34

Table 11. Sleep pattern and the prevalence (%) of overweight and obesity in Saudi adolescents………………….…………………………………………………….…. 36

Table 12. Family size and the prevalence (%) of overweight and obesity in Saudi adolescents.………………………………………………………….………………. 37

Table 13. Family history of obesity and the prevalence (%) of overweight and obesity in Saudi adolescents.………………………………………………….…….……. … 37

Table 14. Economic/social class and the prevalence (%) of overweight and obesity in Saudi adolescents.…………………..…………………………………....……….. 38

Table 15. Mother education and the prevalence (%) of overweight and obesity in Saudi adolescents.…………………………………………………………….…….. 39

Table 16. Father’s education and the prevalence (%) of overweight and obesity in Saudi adolescents.…………………………………………………………….…….. 41

Table 17. Working mother and the prevalence (%) of overweight and obesity in Saudi adolescents.………………………………………………….…………..……………… 42

Table 18. School environment and the prevalence (%) of overweight and obesity in Saudi adolescents.……………………………………………….…….…………..…44

Table 19. Urbanization and the prevalence (%) of overweight and obesity in Saudi adolescents.………………………………………………….…………..…………… 44

List of Figures

Figure 1: Determinants of Determinants of the general health of population.…………… 6

Figure 2: Berkman and Glass’s conceptual framework of how social networks have an impact on health.………………………………………………………………… 7

Figure 3: Ecological model of Social Determinants of Overweight and Obesity in Saudi Adolescents.………………………………………………………….…… 18

Figure 4: Search strategy for review on prevalence and social determinants of overweight and obesity in adolescents in Saudi Arabia……………………….…. 19

Figure 5. Key variables data Screening form………………………………………………... 20

Figure 6. Administrative (A) and provincial (B) regions of Saudi Arabia…………..…… 22

Figure 7. Study population compared to total and adolescent populations of Saudi Arabia…………………………………………………………………... 25

Figure 8. Prevalence rates of overweight and obesity reported in the 2002 and 2010 national (population based) surveys in Saudi male (A) and female (B) adolescents. …….………………………………………………………….……27

Figure 9. Trend of overweight and obesity in Saudi male and female adolescents estimated from calculated yearly mean prevalence rates reported by reviewed regional studies ……………………………………………………………………...28

Figure 10. Meta-analysis: Fast food/Soft drinks and prevalence (%) of overweight and obesity in Saudi adolescents...... 30

Figure 11. Meta-analysis: Physical activity and the prevalence (%) of overweight and obesity in Saudi adolescents.…………………………………………...... … 33

Figure 12. Meta-analysis: TV/Computer screen time and the prevalence (%) of overweight and obesity in Saudi adolescents.……………………………………35

Figure 13. Meta-analysis: Economic/Social class and prevalence (%) of overweight and obesity in Saudi adolescents.……………………………………………..…. 38

Figure 14. Meta-analysis: Mother’s education and prevalence (%) of overweight and obesity in Saudi adolescents.………………………………………..…..….40

Figure 15. Meta-analysis: Father’s education and prevalence (%) of overweight and obesity in Saudi adolescents.…………………………………………...….. 42

Figure 16. Meta-analysis: Working mothers and prevalence (%) of overweight and obesity in Saudi adolescents.………………………………….…………..... 43

Figure 17 Different types of interventions to tackle obesity.……………………………...57

List of Appendices

Appendix 1. Summary of Reviewed Articles & Social Determinants of Overweight and Obesity………………………………………………………………………. 76

Appendix 2. Summary of Reviewed Articles & Prevalence Rates of Overweight and Obesity……………………………………………………………………….. 77

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Chapter 1 INTRODUCTION 1 Introduction. 1.1 Why obesity?

Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health. In adults, overweight is defined as body mass index (BMI) ≥ 25 [BMI = weight (kg) / height (m2)] and obesity is defined as BMI ≥30. Raised BMI is a major risk factor for non-communicable diseases (NCDs) such as cardiovascular diseases (mainly heart disease and stroke), which were the leading cause of death in 2012; hypertension, diabetes; musculoskeletal disorders (especially osteoarthritis); and some cancers (including endometrial, breast, ovarian, prostate, liver, gallbladder, kidney, and colon) (1).

In children aged between 5–19 years, the overweight classification is BMI-for-age > 1 standard deviation (≥85th percentile to <95th percentile) and obesity is > 2 standard deviations (≥95th percentile) above the WHO Growth Reference median (2). Childhood obesity is associated with increased future risk of hypertension, breathing difficulties, fractures, psychological effects, insulin resistance and early markers of cardiovascular disease. In addition, an obese child is more susceptible to develop obesity, disability and premature death in adulthood (1).

Obesity has nearly tripled worldwide since 1975. More than 1.9 billion (39%) adults (18 years and older) were overweight in 2016, out of which >650 million (13%) were obese. Similarly, the prevalence of overweight and obesity among children and adolescents aged 5-19 years has risen significantly from 4% in 1975 to over 18% in 2016, with >340 million children and adolescents being overweight or obese (1). The prevalence of obesity varies across different nations, ranging from below 5% in Japan, to over 60% in Nauru. Obesity prevalence among children and adolescents aged 5-19 is extending into the developing world from the developed nations.

Obesity is a key risk factor for many non-communicable diseases (NCDs), and the risk increases with increase in the level of obesity (3). NCDs have become the world’s leading causes of death, accounting for 71% of all deaths globally in 2016, claiming the lives of 40.5 million people (3). It

2 is very important to note that overweight and obesity, along with their related NCDs, are mostly preventable (1).

In 2015, more than 190 world leaders committed to 17 Sustainable Development Goals (SDGs) to help end extreme poverty, fight inequality & injustice, and fix climate change (4). The 2030 Agenda for Sustainable Development adopted at the United Nations Summit on Sustainable Development in September 2015, recognizes NCDs as a major challenge for sustainable development. Goal 3- Target 3.4 of the SDGs is to reduce by one third premature mortality from NCDs through prevention and treatment and promote mental health and wellbeing by 2030. NCDs were not addressed in the Millennium Development Goals (MDGs). Both for SDG 3 and also for other SDGs, increased consideration of the needs of adolescents and groups that have been traditionally disadvantaged is critically needed (5).

1.2 Why adolescents?

Adolescence (the period between ages 10 and 19 years) is the sensitive phase, during which the quality of the physical, nutritional and social environments may change patterns of health and development into later life (6). Currently, there are about 1.2 billion adolescents in the world (7). Overweight and obesity increase markedly across adolescence, from age 10 to 19 years. This increase is more evident in obesity that has a tenfold increase in four decades (8). Adolescents who are obese are five times more likely to be obese in adulthood than those who were not obese, representing a lifelong personal burden and long-term societal impacts. Around 80% of adolescents who are obese will still be obese in young adulthood, and around 70% will be obese over age 30 (9).

Until recently, adolescent health was neglected in global health and adolescent health services were almost absent in most of the developing world (10). In the last few years the importance of adolescent health became under focus. This was clearly evident in the Global Strategy for Women’s, Children’s and Adolescents’ Health initiated by the UN Secretary-General in

September 2015 (11) and in the very comprehensive reports that followed (6,8,12). However, practical programs are still weak and poorly implemented (6).

In many countries, the focus of health policy is shifting from infectious diseases in early life to NCDs in older adults (12,13). Adolescence largely determines the life course routes of health and wellbeing. Reasons behind bringing adolescents into more focus include the subject of optimizing health, fitness, and capabilities in addition to minimizing risks to health and wellbeing, and the knowledge that disparities established by young adulthood persist and account for many of the inequalities in health (including type 2 diabetes, cardiovascular disease, cancer, and other NCDs) and wellbeing in later life (14). The ageing populations with a disease burden dominated by NCDs made the subject of addressing adolescent health risk factors very critical (15). These risk factors include physical inactivity, poor diet, obesity, tobacco use, and alcohol and illicit substance use (6). Specific policy interventions are needed to control the continuous rise in prevalence of adolescent health risks, including obesity, due to the combination of increasing wealth and unrestrained marketing. International best practice for adolescent NCD risks, such as tobacco and alcohol control and taxation of unhealthy food, should be identified and adopted by all countries, in addition to evaluating new interventions (6).

1.3 Why Saudi Arabia?

In 2014, Saudi Arabia became the world’s 19th-largest economy (up from 27th largest in 2003) making it one of the fastest growing economies (16). Saudi Arabia’s household income rose by 75% during the decade 2003 to 2013 driven by higher public-sector employment and wages (16). It also underwent a significant modernization that brought prosperity and change to Saudi society. In addition, about 83 percent of the Saudi population lives in cities, a degree of urbanization that is larger than in some Western European countries (16). These changes were accompanied with dietary changes which lead to greater consumption of foods high in added sugars, salt, and unhealthy fats, and low in important micronutrients (6). Combined with decreases in physical activity, these patterns have fueled the increasing rates of obesity in Saudi Arabia shown in table 1 (8).

Table 1. Comparison of the prevalence of Overweight and Obesity according to BMI by sex in Saudi Arabia between 1975 and 2014. BMI-body mass index. (Cited from reference 5, appendix table 5).

Obesity is a key risk factor for many NCDs, and the risk increases with increase in the level of obesity (17). NCDs are an increasing public health and development challenge in Saudi Arabia. They kill more than 90,000 people per year in Saudi Arabia and are responsible for 78% of all deaths. Cardiovascular disease alone accounts for nearly half (46%) of all deaths in Saudi Arabia (18). In addition, NCDs in Saudi Arabia are causing a surge in health care costs and social care and welfare support needs, as well as putting an increasing burden on school and work absenteeism, presenteeism and employee replacement costs (19). These indirect costs reduce productivity and economic competitiveness. While the current epidemiological picture is alarming, and the future projections are cause for an emergency response, significant health and economic losses can be mitigated by implementing a set of proven interventions. Since adolescents are adversely affected by NCDs and vulnerable to risk factors, including obesity, leading to unhealthy transitions to adulthood, they are a key stakeholder group at the center for tackling NCDs (20) and achieving sustainable development in Saudi Arabia.

The SDG review reaffirms Saudi Arabia’s commitment to the 2030 Agenda for Sustainable Development and the achievement of the SDGs, both at the national and international levels. Vision 2030 of the Kingdom of Saudi Arabia was launched and approved by the Council of Ministers in April 2016 (21). The underpinning quest of Vision 2030 is to address current regional and international challenges, maintain development gains, diversify and stimulate economic growth and end its reliance on oil as the mainstay source of income. Vision 2030 gives due attention to the promotion of preventive care under the Vision’s theme of “vibrant society”. The theme includes several educational and other initiatives and programs. In this regard, several initiatives have been prepared with respect to cardiovascular diseases, diabetes, respiratory disease and obesity. Under these initiatives, campaigns were launched to promote awareness as to the health risks and the bad health habits associated with these diseases, along with the proper healthy practices to prevent and eliminate related health risks, including obesity (21).

1.4 Why social determinants?

Social determinants of health are the conditions in which individuals are born, grow, develop, live, work, and age (22). They are the root causes of observed social inequities in health and understanding them is needed before effective policies can be formulated to deal with them (23). These determinants of the general health of the population were conceptualized by Dahlgren and Whitehead as rainbow-like layers of influence that emphasize interactions. The individual lifestyles in this model are surrounded by social norms and networks, followed by living and working conditions, which are linked to the wider socioeconomic and cultural environment (Figure. 1) (23).

Figure 1: Determinants of the general health of population.

The center of this model represents factors that influence individual’s health, such as, age, sex and constitutional characteristics that are largely fixed, surrounded by 4 influential categories that are theoretically modifiable by policy.

1.4.1 Individual lifestyle factors:

The innermost layer represents personal behavior factors, such as smoking, drinking, diet and physical activity. These personal behaviors are socially patterned, contributing to some of the observed social inequities in health. In lifestyle-related health, the reasons why lifestyle is socially patterned need to be understood for reducing social inequities.

1.4.2 Social and community network:

The second layer represents the nature of human relationships and how individuals interact with their peers and immediate community and are influenced by them. The health and well-being of an individual and the health and vitality of entire populations depend on the degree to which an individual is interconnected and embedded in a community (24). Berkman & Glass proposed a conceptual model that sums up the body of evidence on this layer. This model visualizes social networks and their relation to the upstream social and cultural context that determines their extent, nature and shape (24). Accordingly, the network structure and function influence downstream social support, access to resources, engagement, and social and person-to-person contact behavior, which are shown in Figure 2. Potential policy entry points along the pathways from macro- to micro- level be identified by this model.

Figure 2: Berkman and Glass’s conceptual framework of how social networks have an impact on health.

1.4.3 Living and working conditions:

This third layer reflects the ability of a person to maintain their health, which is influenced by their living and working conditions, food supply, and access to essential goods and services. Over many decades, it has been shown that population health can be improved by improvements in living and working conditions, food supply, and access to essential goods and services, such as education and health care (23). Actions on this layer of determinants are very important for reducing social inequities in health, as there are strong social gradients in these factors. Policies concerning these determinants, however, span several sectors, and the response needs to be equally multisectoral.

1.4.4 General socioeconomic, cultural and environmental conditions:

The outermost layer contains the influences that prevail in the overall society, whether economic, cultural, environmental or mediator of population health (23). These influences are the maim driver for the generation of social inequities in health and are related to the macropolicy environment, which includes neo-liberal economic growth strategies that have widened income inequalities and increased poverty. The increasing globalization of national economies has reduced the possibilities for national governments to influence these trends. At the same time, the actions of major players on the financial markets are of increasing importance, not only on these markets, but also on economic and social development in general. From an equity-in-health perspective, this calls for intensified efforts to strengthen international organizations and cooperation, focusing on how economic policies can promote human development and reduce social inequities (23). Assessments of the impact of these broader upstream determinants of health and social inequities in health are often lacking, while the focus of assessments of the problem is generally only on the effects of interventions in specific downstream determinants. Intensified efforts must therefore be made to identify and, whenever possible, quantify the effects of different economic growth strategies, income inequalities and poverty on the health of different socioeconomic groups (23).

The determinants of health that can be influenced by individual, commercial or political decisions that can be positive health factors, protective factors, or risk factors.

Positive health factors: These contribute to the maintenance of health. Fundamental positive health factors are, for example, economic security, adequate housing and food security. Control over life outcomes and enjoying good relationships in the home and other emotionally rewarding social relationships are also important positive health factors (25).

Protective factors. These are factors that eliminate the risk of, or facilitate resistance to, disease. The classical example is immunization against a variety of infectious diseases. Psychosocial factors, such as social support and a sense of purpose and direction in life, are also increasingly recognized as factors that protect health (26). Healthy diets, such as the Mediterranean diet with a high consumption of fruit and olive oil, are also considered to be protective (27).

Risk factors or risk conditions: These cause health problems and diseases that are potentially preventable. These risk factors or risk conditions can be social or economic or can be associated with specific environmental- or lifestyle-related health hazards, such as polluted air and smoking.

Social determinants of adolescent health lie largely outside the health service sector with major influences of peers, media, education, and the beginning of workplace influences (6). They contribute to the dramatic increase seen within specific countries or globally. These determinants vary between countries depending on the social status of each country (28). A full understanding of the relationships between the selected determinants and obesity can provide the foundations for developing interventions promoting healthier individuals and decreasing the prevalence of obesity in a given country. Therefore, identifying such determinants is important to help inform recommendations for policy makers, practitioners and researchers for implications for health promotion and prevention and for further research.

1.5 Social determinants of overweight and obesity in adolescents.

It is well known that imbalance between energy intake and expenditure can lead to increase in overweight and obesity, and that positive energy balance is closely related to dietary intake preferences and lifestyle adopted (29). However, these factors are modulated by many other determinants related to the individual’s genetic background and lifestyle as well as to their socioeconomic and cultural environment. Social determinants related to overweight and obesity in adolescents are reported in the literature separately or in small groups, and we summarize them in the following:

1.5.1 Dietary habits (patterns/contents)

Diet plays a major role in the development of obesity and healthy diet helps protect against NCDs, including diabetes, heart disease, stroke and cancer (30). The type and amount of food that the individual eats are affected by availability, pricing, and personal choices, in addition to advertising, social customs and cultural influences. Adolescents globally have experienced considerable changes in their diet over the last few decades due the fast-growing economies, urbanization, and globalization. These changes resulted in a shift away from healthier diets that consist of whole grains, vegetables, fruits with small amounts of meat and fat, to a diet rich in calories with highly processed food containing large amounts of salt, sugar, and saturated fat. In addition, the great and easy access of adolescents to soft drinks and other sugar-sweetened beverages added considerably to their caloric intake (30). The dietary factors that can be examined include consumption of vegetables, fruits, breakfast, fast food, sugary beverages, snack foods and sweets intake.

1.5.2 Physical activity

There is a strong relationship between health outcomes and PA that persists throughout life, including adolescence. Being a key determinant of energy expenditure, regular and adequate levels of physical activity are essential to energy balance and weight control in adolescents. In addition, they can improve mental health by reducing stress reactions, anxiety and depression, which are becoming common among adolescents (31). Furthermore, they can improve functional health and reduce the risk of NCDs (32).

The term "physical activity" does not essentially mean "exercise". Exercise represents a subcategory of physical activity and is defined as planned, structured, repetitive, and purposeful movements that aim for the improvement or maintenance of one or more components of physical fitness. In addition to exercise, physical activity includes other activities which involve bodily movement and are done as part of playing, working, active transportation, house chores and recreational activities (33). Therefore, increasing physical activity is a social, not just an individual problem and it demands a population-based, multi-sectoral, multi-disciplinary, and culturally relevant approach (33). With the recent socioeconomic development, adolescents became less physically active and the activity levels required for work and transportation were significantly reduced. In addition, several environmental factors linked to urbanization, such as high-density traffic, limited sport/recreation facilities, lack of parks and sidewalks, air pollution, fear of crime and violence in outdoor areas discouraged adolescents from becoming more active (33). The physical activity factors that can be examined include physical activity/physical exercise practice in minutes or METS/ day or week.

1.5.3 Sedentary behavior

Sedentary behavior is not the lack of Physical activity but is a group of individual behaviors that are dominated by sitting or lying with very low energy expenditure that can take place at home, school or work (34). Furthermore, it was shown that sedentary activity, in the form of television (TV) viewing and physical activity are different entities in terms of associated metabolic risk in children and adolescents (35). With the improvements in socioeconomic status, sedentary behaviors have increased dramatically among adolescents and they include watching TV, using computers, playing video games and surfing the internet, and use of "passive" modes of transport (36, 37).

1.5.4 Sleep patterns/Stress/Smoking

Multiple reports suggest that chronic sleep restriction can lead to obesity in adults, adolescents and children (38-40), and that the duration of sleep is an independent risk factor for overweight and obesity in children (41,42). The link between sleep duration and obesity can be explained by several mechanisms (43). Studies have shown that sleep is an important regulator of many biological and

12 physiological functions, such as appetite, energy balance, and weight maintenance, and that control of body weight and nutrient metabolism are greatly affected by the number of hours of sleep. (40,44). Both short and long periods of habitual sleep are linked to obesity (45). Short sleep duration can lead to a reduction in the satiety hormone leptin and an increase in the hunger hormone ghrelin that cause an increase in appetite (44,45). The fast-growing economies and rapid advancement in technology have resulted in extensive television viewing and use of other electronic media (computers, videogames and the internet), which made short sleep duration a major problem among adolescents.

1.5.5 Family history of obesity/Family size

Family factors play an important role in the development of overweight and obesity in children and adolescents. In addition to the genetic effect, food preferences and availability and habits within a family can easily influence what children and adolescents eat. Also, family lifestyle and habits (physically active or sedentary) can influence children and adolescents (55). High rates of

13 overweight and obesity are observed in adolescents with a family history of obesity (56), which can be related to the mentioned family factors as well as to genetic factors.

1.5.6 Household income

Lower income households tend to have higher rates of obesity in the United States and other developed countries (58,59). A possible explanation is that the low-income families are more exposed to junk food and other cheap calories including processed sugars (69). However, Analysis of data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES) demonstrates that adolescent obesity prevalence patterns by household income are less consistent by race (61).

1.5.7 Parental education

It is assumed that parental education is supposed to improve awareness of all family members on healthy food selections (62). However, recent studies suggest that parental education is associated with increased rate of overweight in children and adolescents (63). This association seems to vary according to the developmental stage of different countries. In higher economic status countries, paternal rather than maternal higher education is associated with more positive influence on lowered child overweight. On the other hand, a more negative influence of maternal higher education on increased child overweight is observed in lower economic status countries (63). These varied associations make it crucial to further examine familial factors when investigating overweight in children and adolescents.

1.5.8 Working mother

Studies have shown that when both parents are working away from their children, there is a high chance that their children will develop overweight and obesity. Working mothers spend less time on preparing food for their children who will eat more restaurant made fast food meals, which are known to increase of overweight and obesity in children and adolescents (64,65). In addition, there will be less supervision and more sedentary behaviors (watching television, using the computer, playing passive video games and surfing the internet) among children and adolescents, which will add to the problem (66). It was estimated that 10% of the rise in childhood obesity is related to maternal employment (67) however, recent studies showed that the size of the problem is more than that (68).

1.5.9 Health literacy

Low food label literacy can lead to increased risk of obesity, high blood lipids, and high blood pressure (69). Also, low level of health literacy is related to many aspects of adolescence health including their body weight. Studies have shown that low health literacy is significantly associated with overweight or obesity in adolescents, which should be considered in all strategies combating adolescence weight problem (70,71).

1.5.10 School food/environment.

School food represents 35-47% of the daily intake of children and adolescents (72). While at school, students are exposed to all types of unhealthy food (such as french fries, chips, pizza, and candies) and beverages (mainly sugar-sweetened beverages) (73-76), all of which can lead to high rate of overweight and obesity in adolescents.

1.5.11 Urbanization.

Recent studies suggest that rapid urbanization accounts for significant shifts in dietary patterns and physical activity (77). Several environmental factors are linked to urbanization, such as high-density

15 traffic, limited sport/recreation facilities, lack of parks and sidewalks, air pollution, fear of crime and violence in outdoor areas discouraged adolescents from becoming more active (33).

1.6 Defining overweight and obesity in adolescents:

As BMI varies with age during childhood and adolescence, the cut-off values used for adults can produce misclassifications of overweight and obesity among 5–19-year-old subjects. Currently, three growth references are commonly considered when assessing weight status in this age group:

1.6.1 International Obesity Task Force system:

International Obesity Task Force (IOTF) system, which is based on data from 6 large, nationally- representative, cross sectional surveys on child growth in Brazil, Great Britain, Hong Kong, the Netherlands, Singapore, and the United States (78). The 2005 IOTF cut-off values are extrapolations of adult BMI cut-off points for overweight (25 kg/m2) and obesity (30 kg/m2) at age 18 years (78) and are widely used internationally.

1.6.2 Centers for Disease Control and Prevention system:

Centers for Disease Control and Prevention (CDC) system (79), which is developed from 5 nationally representative surveys of American children – from the National Health Examination Survey and NHANES (79). The CDC defines overweight as 85th ≤BMI< 95th percentiles, and obesity as BMI ≥95th percentile of the 2000 CDC gender-specific BMI-for-age growth charts (79).

1.6.3 World Health Organization system:

World Health Organization (WHO) system (80) is derived from a combination of United States National Centre for Health Statistics 1977 pooled child growth data, and the WHO Multicenter Growth Reference Study in six countries (Brazil, Ghana, Norway, India, Oman, and the United States) (80). The 2007 WHO classification system defines BMI-for-age >+1 standard deviation

(SD) of the WHO growth standard median as overweight (equivalent to BMI=25 kg/m2 at 19 years) and >+2 SD as obesity (equivalent to BMI=30 kg/m2 at 19 years) (80).

Since the prevalence rates of overweight and obesity differ according to these BMI systems (81,82), the choice of BMI system is critical in assessing excess childhood weight at a population level.

1.7 Objectives.

This review aims to highlight the magnitude and to assess the trend of overweight and obesity in Saudi adolescents over the reviewed period, as well as, to look at this problem from behavioral and social standpoint by identifying and constructing an ecological model for social determinants of overweight and obesity in adolescents and discussing them in relation to the Saudi setting.

Chapter 2 METHODS Methods. 2.1 Identifying and constructing an ecological model for Social determinants of overweight and obesity relevant to Saudi adolescents:

The social determinants of overweight and obesity used in this review are the ones we extracted from the literature (section 1.5.5-1.5.11) as factors that can influence body weight (those related to physical activity or diet) as well as potential causes or preventive aspects of overweight and obesity in adolescents that are related to the fast-growing economy of Saudi Arabia (such as large household income, significant modernization, high degree of urbanization…etc) and they included:

1. Dietary habits (patterns/contents).

2. Physical activity.

3. Sedentary behavior (TV/computer screen time, playing video games and surfing the internet time, and use of "passive" modes of transport).

4. Sleep pattern/ Stress/Smoking.

5. Family history of obesity/Family size.

6. Household income (economic/social class).

7. Parental education.

8. Working mother.

9. Health and label literacy.

10. School food/environment.

11. Urbanization.

We grouped these determinants of overweight and obesity in adolescents in an ecological model (Figure 3) to show their relation to the categories of social determinants of health that include; age, sex and constitutional characteristics, individual lifestyle factors, social and community networks, norms and networks, living and working conditions and socioeconomic, cultural and environment conditions.

Figure 3: Ecological model of Social Determinants of Overweight and Obesity in Saudi Adolescents.

2.2 Protocol and Search strategy:

This review was conducted using standard searching methods. The search engines PubMed, Medline, EMBASE, and PsycINFO were searched up to Dec 31, 2018. Search terms were a combination of [“family size” OR “parents employment” OR “economics” OR “household factors” OR “food security” OR “social media” OR “diet patterns” OR “diet content” OR “physical activity” OR “stress” OR “smoking” OR “sleep patterns” OR “urbanization” OR “region” OR “school/food environment” OR “label literacy” OR “gender” AND “overweight” OR “obesity”

AND “adolescents” AND “Saudi Arabia”]. No language or publication date restrictions were applied. Studies dated back to 1982 Studies were considered for inclusion if they present qualitative or quantitative data on adolescents in the including relevant study designs. These included peer-reviewed studies that reported on prevalence, and/or characteristics of overweight, and/or obesity in adolescents in Saudi Arabia. Studies unrelated to obesity and that did not provide data on the determinants of overweight and/or obesity in adolescents in Saudi Arabia were excluded. Non-adolescent studies (younger than 10 and older than 19), duplicates, reviews and studies on non-Saudi adolescents were further excluded. PRISMA statement in reporting systematic reviews from the observational studies was used (83). Based on the PRISMA criteria, the flow chart in figure 4 shows the search strategy for identification of the databases, screening studies, assessing for eligibility, and the final studies that met selection criteria.

Figure 4: Search strategy for review on prevalence and social determinants of overweight and obesity in adolescents in Saudi Arabia.

2.3 Analysis:

All studies identified through the database searches were analyzed. The titles, abstracts, and full texts of these papers were screened for the inclusion criteria. Included studies were screened and abstracted (Figure 4).

Figure 5. Key variables data Screening form.

A summary was created by tabulating data to facilitate comparison between studies. Data extraction form (Microsoft Excel spreadsheet) was created and data was presented based on the following key variables, (i) author; (ii) year of publication; (iii) number of subjects; (iv) number of males; (v) number of females; (vi) population age range; (vii) type of publication journal; (viii) study design; (ix) region of study; (x) BMI reference standards of overweight and obesity assessment criteria (xi) related social determinants (Appendix 1) (Table 2). STROBE guidelines were applied on the studies that provided data on the social determinants of overweight and obesity in Saudi adolescents to demonstrate how much these studies fulfill the reporting requirements (84).

Appendix 1. Summary of Reviewed Articles & Social Determinants of Overweight and Obesity. Study Characteristics Determinants of Overweight and Obesity Family size Social Label Stress/ Diet Total Male Female Age Publication Study OW/OB & Family Parents' Parents’ Economics/ media & literacy/ Physical smoking/ Mobility/ School/ food # Author Year Region patterns/ Hx of education employment Household screen general activity sleep urbanization environment # # # (years) Journal Design criteria contents obesity factors time education patterns 1 El-Hazmi, et al. 2002 6352 3142 3210 9-18 International CS National IOTF 2 El Mouzan, , et al. 2010 7551 3853 3698 13-18 National CS National WHO+CDC

3 Al-Nuaim, et al. 1996 3223 3223 14-18 International CS C/E/S/W/N CDC 4 Ghabrah, et al. 1997 4042 2870 1172 10-19 National CS Western (Jeddah) CDC 5 Abahussain, et al. 1999 676 676 12-19 International CS Eeastern CDC 6 Abalkhail, et al. 2002 2860 1403 1457 16-16 National CS Western (Jeddah) CDC ü ü 7 Al-Rukban, et al. 2003 885 885 12-20 National CS Central (Riyadh) CDC ü ü ü 8 Al-Almaie,et al. 2005 1766 675 1091 14-19 National CS Eeastern CDC 9 Farghaly, et al. 2007 767 327 440 12-18 National CS Southern (Abha) WHO 10 Farahat, , et al. 2007 1454 657 797 12-19 National CS E/N/W WHO 11 Al-Hazzaa, H. 2007 350 175 175 10-14 National CS Central (Riyadh) CDC 12 Al-Saeed, et al. 2006 1610 1610 10-17 International CS Eastern (Alkhobar) IOTF ü ü ü 13 Amin, et al. 2008 1139 1139 10-14 International CS Eeastern (AlHassa) IOTF ü ü ü ü ü 14 Mahfouz, et al. 2008 2696 2696 11-19 International CS Southern (Abha) WHO ü ü ü ü 15 Khalid, et al. 2008 1884 875 1009 10-15 International CS Southern (Asser) WHO ü 16 Taha, A. 2008 2571 1240 1331 13-18 International CS Eastern (Alkhobar) NA 17 Abou-Zeid, et al. 2009 284 141 143 12-19 International CS Western (Taif/Hada) CDC 18 Bawazeer, et al. 2009 5877 3244 2633 10-19 International CS Central (Riyadh) CDC ü 19 Dossary, , et al. 2010 2978 1659 1319 10-15 International CS Eastern (Alkhobar) CDC 20 Washi, , et al. 2010 239 112 127 13-18 International CS Western (Jeddah) CDC 21 Collison, , et al. 2010 9433 5033 4400 10-19 International CS Central (Riyadh) CDC 22 Abahussain, N. 2011 321 321 15-19 National CS Eastern (Alkhobar) CDC 23 AbdAllah, , et al. 2011 140 70 70 10-19 National CS Western (Jeddah) WHO 24 Mahfouz, , et al. 2011 1869 1249 620 11-19 National CS Southern (Abha) WHO ü ü 25 Shatoor, , et al. 2011 1249 1249 15-19 International CS Southern (Abha) WHO 26 Al-Hazzaa, , et al. 2012 2906 1400 1506 14-19 International CS E/C/W IOTF ü ü ü 27 Al-Hazzaa, , et al. 2012 2768 1379 1389 15-19 National CS E/C/W IOTF 28 Al-Musharaf, et al. 2012 185 82 103 13-17 International CS Central (Riyadh) IOTF 29 Al-Nakeeb, , et al. 2012 1138 600 538 15-17 International CS Eastern (Alhassa) IOTF ü 30 Mahfouz, , et al. 2012 1869 1249 620 12-19 National CS Southern (Abha) WHO 31 Al-Nuaim, , et al. 2012 1270 663 607 15-19 International CS Eastern (Alhassa) IOTF ü 32 AlBuhairan, et al. 2012 1719 705 1014 10-18 International CS Central (Riyadh) NA 33 El Mouzan, , et al. 2012 3122 1581 1541 13-18 National CS C/S/W/N CDC 34 Al Alwan,, et al. 2013 1243 542 701 10-16 International CS Central (Riyadh) WHO ü ü ü 35 Al-Ghamdi, S. 2013 397 201 196 11-14 National CC Western (Madinah) IOTF ü 36 Al-Hazzaa, , et al. 2013 1618 767 851 14-18 International CS Eastern (Alkhobar) IOTF 37 Ghamdi, , et al. 2013 197 197 9-14 International CS Western (Madinah) IOTF ü 38 Al-Hazzaa, H. 2013 2852 1378 1474 15-19 International CS E/C/W IOTF ü 39 Al-Hazzaa, , et al. 2014 2908 1401 1507 14-19 International CS E/C/W IOTF 40 Al-Sobayel, , et al. 2015 2888 1388 1500 14-17 International CS E/C/W IOTF 41 Alenazi, , et al. 2015 523 523 15-19 International CS Northern (Arar) CDC ü ü ü 42 Al-Mutairi, et al. 2015 426 221 205 15-25 International CS Central (Riyadh) NA 43 El-Kholy, T. 2015 135 70 65 16-19 International CS Western (Jeddah) NA 44 Musaiger, et al. 2016 968 518 450 15-18 International CS Eastern (Dammam) WHO+IOTF 45 Al Shammari, et al. 2017 1420 700 720 13-18 International CS Central (Hayel) WHO 46 Bajamal, et al. 2017 405 405 13-18 International CS Western (Jeddah) IOTF 47 Al Dahi, et al. 2017 1832 852 980 11-19 National CS Northern (Tabuk) WHO ü ü ü ü 48 Farsi, et al. 2017 801 386 415 15-19 National CS Western(Jeddah) WHO 49 Adaili, et al. 2017 257 257 15-17 International CS Southern (Albahah) CDC ü ü ü ü ü 50 Alazzeh et al. 2018 1495 1495 12-19 International CS Central (Hayel) WHO ü ü ü ü ü 51 Al-Kadi, et al. 2018 108 34 74 15-19 International CS Central (Qassim) NA 97666 54249 43417 4 9 4 7 6 6 0 7 3 2 1 CDC =Centers for Disease Control; CC = Case Control; CS = Case Control; IOTF =International Obesity Task Force; NA=not available; WHO=World Health Organization

Table 2. Key variables data & Social determinants of Overweight and Obesity in Saudi Adolescents. (see Appendix 1).

This review was designed to evaluate and assess the trend of overweight and obesity in Saudi adolescents and to identify and construct an ecological model for social determinants of overweight and obesity in adolescents and discuss them in relation to the Saudi setting. Saudi Arabia is divided into 13 administrative regions (figure 6-A), which are described 5 provinces (Northern, Southern, Eastern, Western and Central) that are used in both national and multiregional studies (85,88,93,111,112, 117,1121-123) (figure 6-B). To evaluate the trend of the prevalence of overweight and obesity in Saudi male and female adolescents, prevalence rates reported from national (population based) surveys were compared with each other. Also, yearly mean prevalence rates calculated from regional and multiregional relatively small studies were estimated and compared to examine the trend over the reviewed period.

Figure 6. Administrative (A) and province (B) regions of Saudi Arabia.

The frequency of each individual determinant was calculated based on the data extracted from each study. When possible, a mean value was calculated for the determinant using values reported in different studies for that determinant. Determinants were presented with their mean prevalence values to reflect the significance of their effect. When possible, a meta-analysis of the studies reporting the determinant and prevalence (%) of overweight and obesity in Saudi adolescents was done with pooled prevalence estimates that were generated using RevMan V.5.3 software. Forest plots were generated to display the overall random-effects pooled estimates with confidence intervals (CIs). Statistical heterogeneity was assessed using the result of the chi-squared test and the value of I2.

Chapter 3 RESULTS

Results. 3.1 Included studies:

The search identified reports that dated back to 1982 and included studies reported before December 31, 2018 (the date of the search). A total of 810 records were initially identified through database search (PubMed, 303; Ovid MEDLINE, 124; PyscINFO, 198, and EMBASE, 185). All study titles and abstracts were screened for inclusion/exclusion criteria and 676 were excluded (Figure 4) because they examined diseases or symptoms related to overweight and obesity (e.g. metabolic syndrome, asthma, sleep…etc.), investigated medical treatment and surgical intervention studies related to overweight and obesity, described biochemical markers related to overweight and obesity, were off topic or duplicated studies, non-Saudi Arabian studies, and non- adolescent studies (younger than age 10 and older than age 19). Full-text assessment of the 134 included articles were performed to identify eligible studies; 83 records were further excluded because they used the same data set of other reports, were review and growth chart reports, or were studies that did not report on prevalence or determinants of overweight and obesity in Saudi adolescents. Finally, 51 studies met the inclusion criteria and were included in the literature review. All these studies were observational studies, 50 were cross-sectional (17, 85-118, 120-134) and one was a case-control design (119) (Appendix 1). Seventeen were published in national journals and 34 in international journals (Appendix 1) (Table 3). Out of the 51 reviewed studies, 41 were single- region (11 central, 10 eastern, 11 western, 7 southern and 2 northern), 8 were multi-province and 2 were national (Table 4). Nineteen studies described one or more of the selected social determinants of overweight and obesity in Saudi adolescents. STROBE guidelines were applied and demonstrated that these 19 studies met between 77.3% and 95.5% of the reporting requirements.

Table 3. Type of publication journals used in the review.

3.2 Study population:

The 51 reviewed studies (17, 85-134) included 97,666 adolescents with 56.9% males (Table 4). The current estimated population of Saudi Arabia based on the 2016 census is 31,742,308 with 57.2% males, out of which 4,638,906 are adolescents with 51.0% males (135) (Figure 7). All province and multi-regional studies included school students, while the national studies were population-based surveys. The distribution (number & %) of males and females in each province/region is shown in Table 4.

Table 4. Distribution (number & %) of subjects included in the studies per region.

Figure 7. Study population compared to total and adolescent populations of Saudi Arabia.

3.3 Determining Overweight and Obesity:

Different BMI reference standards were used to define overweight and obesity in Saudi Arabian adolescents in the reviewed studies. Sixteen studies used the CDC, 16 used IOTF and 13 used WHO criteria. One study used both WHO and IOTF and another compared CDC with WHO criteria. In 5 studies reference standards were not reported (Appendix 1) (Table 5). One of the national surveys used CDC, the other used IOTF and the third compared CDC with WHO criteria.

Table 5. BMI reference standards used to define overweight and obesity in Saudi Arabian adolescents in the reviewed studies. CDC = Centers for Disease Control; IOTF = International Obesity Task Force; WHO = World Health Organization.

3.4 Prevalence Rates of overweight and obesity:

Prevalence rates were reported in different ways within the reviewed articles. They were reported as rates of either overweight alone, obesity alone or overweight and obesity together, in either males alone, females alone or males and females together (Appendix 2). The prevalence rates of overweight and obesity for male and/or female adolescents reported in the 50 cross-sectional studies were used for the evaluation of the trend over the reviewed period.

3.4.1 Prevalence Rates of overweight and obesity from national surveys:

There were 2 national (population based) surveys, one in 2002 and the other in 2010 (88,103). Reported prevalence rates of overweight and obesity in Saudi adolescents from these surveys were 16.0% and 6.2% for males and 17.4% and 7.2%, respectively in the year 2002, and 25.7% and 11.5% for males and 27.4% and 10.0%, respectively in the year 2010 (Figure 8, A and B). These numbers clearly show a clear increase in the prevalence of overweight and obesity in both males and females between the years 2002 and 2010, from 22.2% to 36.2% for males and from 24.6% to 38.4% for females, respectively (Figure 8, A and B).

Figure 8. Prevalence rates of overweight and obesity reported in the 2002 and 2010 national (population based) surveys in Saudi male (A) and female (B) adolescents.

3.4.2 Prevalence Rates of overweight and obesity from regional and multiregional studies:

Although prevalence rates estimated from regional studies with a specific population (e.g. school based, as in the case of all reviewed regional studies) are not as accurate as those estimated from national surveys, we decided to evaluate the trend of prevalence rates of overweight and obesity of male and female adolescents reported in these studies for the following reasons: i- the large number of reviewed studies that were reported from all regions and included a large number of males and females with a ratio close to the that of the total and adolescent populations in Saudi Arabia, ii- the fact that school based adolescent population in Saudi Arabia represents the majority of adolescents in the country, as they exceeded 93% of total adolescent population in the year 2016 (70) for both males and females, and, iii- no national survey of overweight and obesity in adolescents has been reported from Saudi Arabia since 2010.

Yearly mean prevalence rates that were calculated from the regional studies are shown in table 6. Prevalence rates calculated for the years 2002 and 2010 were relatively in line with the prevalence rates estimated from national surveys for males and females, 28.3% and 25.5% vs 22.2% and 24.6%, respectively, for the year 2002 and 39.1% and 42.6% vs 36.3% and 38.4% for the year 2010. It was noticed that prevalence rate continued to increase for males reaching 48.3% in the year 2018, on the other hand, it tended to fluctuate and decreased for females reaching 27.6% in the year 2017.

Table 6. Yearly mean prevalence (%) rates standards used to define overweight and obesity in Saudi Arabian adolescents in the reviewed regional and multiregional studies.

Figure 9. Trend of overweight and obesity in Saudi male and female adolescents estimated from calculated yearly mean prevalence rates reported by reviewed regional studies.

3.5 Social Determinants of overweight and obesity.

Out of the 51 reviewed studies, there were 49 reports from 19 studies about social determinants of overweight and obesity, as some studies reported information about more than one social determinant (Appendix 1). The number of reports for each determinant were generally small and varied from 0 (for Label literacy and social media) to 9 (for parents’ education) (Table 7).

Table 7. Number of reviewed reports for each determinant of overweight and obesity.

3.5.1 Diet patterns/contents:

There were 5 studies (90,96,110,124,130) on the diet patterns/contents and adolescent overweight and obesity in 8149 subjects (6643 males and 1506 females). Three reports evaluated the effect of fast food and soft drink intake and the prevalence of overweight and obesity (Table 8-A). Meta- analysis results of these 3 studies in male adolescents (Figure 10) indicated a statistically significant positive association between fast food and soft drink consumption 2-4 times/week and odds of overweight and obesity – a pooled odds ratio of 1.62 (95% CI 1.62 to 2.43) with p=0.02. I2 was 35% and may suggest low-moderate heterogeneity. Two other reports (Table 1-B) indicated a positive association between skipping breakfast and overweight and obesity in Saudi adolescents with a higher mean prevalence of 30.6% vs 14.7%. Another report (Table 8-B) indicated a negative association between overweight and obesity and vegetable consumption >3 times/week. negatively associated with higher vegetable intake. More studies with standardized format that cover other food contents are needed to further delineate the effect of diet pattern and content on overweight and obesity in adolescents in Saudi Arabia.

Table 8-A. Fast food and soft drink intake and the prevalence (%) of overweight and obesity in Saudi adolescents.

Figure 10. Meta-analysis: Fast food/Soft drinks and prevalence (%) of overweight and obesity in Saudi adolescents.

Table 8-B. skipping breakfast and vegetable intake and the prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.2 Physical activity:

There were 7 reports (90,110,113,118,124,130,132) on physical activity and adolescent overweight and obesity in 4571 subjects. Three studies (Table 9-A) evaluated the effect of physical activity duration in minutes. The evaluation parameters varied between studies and included physical activity for >30 minutes/week, >60 minutes/week, and > 3 times/week. Meta-analysis results of these 3 studies (Figure 11) indicated a no statistically significant association between less physical activity/week and odds of overweight and obesity – a pooled odds ratio of 0.38 (95% CI 0.12 to 1.23) with p=0.11 and I2 = 88% suggesting considerable heterogeneity. Another report (Table 9- B) used total METS (minute/week) for the evaluation and demonstrated a positive association between less physical activity/week (p=<0.05) in both males and females. Other 3 reports showed that a high % of adolescents never exercise, mainly females (reached 100% in one study) (Table 9-B). These results might not reflect the current status because of the recent drastic changes in lifestyle and factors/facilities that adolescents, especially females, are exposed to in Saudi Arabia within the past year. More new studies with standardized protocols are needed to further delineate the effect of this determinant on overweight and obesity in adolescents in Saudi Arabia.

Table 9-A. Duration of physical activity and the prevalence (%) of overweight and obesity in Saudi adolescents.

Figure 11. Meta-analysis: Physical activity and the prevalence (%) of overweight and obesity in Saudi adolescents.

Table 9-B. The practice of physical activity and the prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.3 Sedentary behavior factors:

There were 6 studies on the association between TV/ computer screen time and overweight and obesity in Saudi adolescents with a total of 7784 subjects. Four studies (119,124,130,133) investigated the association between TV/ computer screen time and the prevalence of overweight and obesity in 3009 subjects (Table 10-A) and 2 studies (97,110) compared the screen time spent by overweight and obese subjects to that spent by normal subjects in 4775 subjects (Table 10-B). The screen time used for the evaluation varied between studies and within the same study from >2 to >6 hours per day, and from weekday to weekend. The prevalence of overweight and obesity was noted to be higher in those with longer time spent on TV/computer. Despite that variation, a meta-analysis was done for these studies (Figure 12) and indicated a statistically significant positive association between longer TV/computer screen time and odds of overweight and obesity – a pooled odds ratio of 1.56 (95% CI 1.18 to 2.06) with p= <0.002 and I2 = 38% and may suggest low-moderate heterogeneity. The other 2 reports (Table 10-B) showed that the number of hours per day of TV/Computer screen time spent by overweight and obese Saudi adolescents was higher than that spent by normal weight adolescents, however only one of these 2 studies showed significant results.

There were no studies about the effect of rapidly growing social media, playing video games and surfing the internet, as well as the use of "passive" modes of transport, in relation to adolescent overweight and obesity in Saudi Arabia. Studies are needed to properly evaluate the effect of sedentary behavior factors on overweight and obesity in Saudi adolescents.

Table 10. TV/Computer screen time and the prevalence (%) of overweight and obesity in Saudi adolescents.

Table 11. TV/Computer screen time spent by Saudi adolescents in relation to body weight.

Figure 12. Meta-analysis: TV/Computer screen time and the prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.4 Sleep pattern/ Stress/Smoking:

Only one study (132) about the association between smoking and the prevalence of overweight and obesity was reported that included 257 female subjects. The prevalence of overweight and obesity was 0% in the smokers and 0.7% in the non-smokers. With these small numbers, the association between smoking and the prevalence of overweight and obesity in Saudi adolescents cannot be evaluated. With a tobacco epidemic being on the rise in Saudi adolescents (136), more current studies are needed to further delineate the effect of this determinant on overweight and obesity.

There were 2 reports (101,110) about the association between sleep pattern and the prevalence of overweight and obesity (Table 11) and they included 2852 male subjects. The parameter used to evaluate the effect of sleep pattern on overweight and obesity was < 7 hours in the first study and < 8 hours in the second study. Both studies showed positive association between decreased number of sleeping hours and overweight and obesity with a reported a p-value of <0.005 in one study and <0.006 in the other. More studies with fixed parameters are needed to properly evaluate the effect of this determinant on overweight and obesity.

Table 11. Sleep pattern and the prevalence (%) of overweight and obesity in Saudi adolescents.

No studies were reported about the association between stress and the prevalence of overweight and obesity in Saudi adolescents. Therefore, studies are needed.

3.5.5 Family history of obesity/Family size:

The association between family history of obesity and the prevalence of overweight and obesity was reported in 2 studies (90,130) that included 2717 subjects (1737 males and 980 females) (Table 13). Both concluded a significant association between overweight and obesity and a positive family history of obesity with p-value of <0.05. However, no values of prevalence were reported in the second study. More studies with fixed parameters are needed to properly evaluate the effect of this determinant on overweight and obesity in adolescents in Saudi Arabia.

There were also 2 reports (96,133) about the association between family size and the prevalence of overweight and obesity (Table 13) and they included 2634 male subjects. The parameter used for the evaluation of the effect of family size on overweight and obesity was > 6 in the first study and > 8 in the second. A family size <6-8 was negatively associated with obesity with a reported a p- value of <0.001in one study and 0.05 in the other. More studies with fixed parameters are needed to properly evaluate the effect of this determinant on overweight and obesity.

Table 12. Family size and the prevalence (%) of overweight and obesity in Saudi adolescents.

Table 13. Family history of obesity and the prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.6 Household income (Economic/Social class):

The association between economic/social class and the prevalence of overweight and obesity in adolescents was reported in 7 studies (92,95,97,98,118,132,133) that included 11218 subjects (5564 males and 5654 females) (Table 14). The group with the higher economic/social class (defined by high income, attending private schools or owning a house) (Table 14) had higher prevalence rates of overweight and obesity in all studies and a higher calculated mean prevalence (30.1% vs 15.1%). Meta-analysis results of these 7 studies (Figure 13) indicated a statistically significant positive association between higher economic/social class and odds of overweight and obesity – a pooled odds ratio of 2.66 (95% CI 1.56 to 4.53) with p= <0.0003. However, I2 was 71%, suggesting substantial heterogeneity. Therefore, more studies with fixed indicators are needed to properly evaluate the effect of economic/social class on overweight and obesity in Saudi adolescents.

Table 14. Economic/social class and the prevalence (%) of overweight and obesity in Saudi adolescents.

Figure 13. Meta-analysis: Economic/Social class and prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.7 Parental Education:

The association between mother education and the prevalence of overweight and obesity in adolescents was reported in 9 studies (92,95-97,108,118,130,132,133) that included 15001 subjects (9376 males and 3625 females) (Table 15). The group with mothers with the highest level of education

39 had higher prevalence rates of overweight and obesity in 8 of the nine studies and a higher calculated mean prevalence (29.6% vs 25.8%). Meta-analysis results of these 9 studies (Figure 14) indicated a statistically significant positive association between mothers with the highest level of education and odds of overweight and obesity – a pooled odds ratio of 1.45 (95% CI 1.18 to 1.78) with p=0.04. However, I2 was 71%, which suggests substantial heterogeneity. It is important to know how much of this effect is confounded by economic/social class. Mother education may not be a risk factor for overweight and obesity, but rates could be higher among higher economic/social class groups who also happen to be more educated. Only 3 out of the 9 reported studies in Saudi adolescents looked at mother education and economic/social class together. Therefore, more studies are needed to properly evaluate the effect of mother education on overweight and obesity in Saudi adolescents, as well as its relation to economic/social class.

Table 15. Mother education and the prevalence (%) of overweight and obesity in Saudi adolescents.

Figure 14. Meta-analysis: Mother’s education and prevalence (%) of overweight and obesity in Saudi adolescents.

The association between father education and the prevalence of overweight and obesity in Saudi adolescents was reported in 6 studies (96,97,108,118,132,133) that included 8699 subjects (7121 males and 1578 females) (Table 16). The group with fathers with the highest level of education had higher prevalence rates of overweight and obesity in all studies and a higher calculated mean prevalence (37.6% vs 27.7%). Meta-analysis results of these 6 studies (Figure 12) indicated a statistically significant positive association between fathers with the highest level of education and odds of overweight and obesity – a pooled odds ratio of 1.58 (95% CI 1.22 to 2.05) with p=0.0005. Heterogeneity was low with an I2 = 10%, suggesting low heterogeneity.

Table 16. Father’s education and the prevalence (%) of overweight and obesity in Saudi adolescents.

Figure 15. Meta-analysis: Father’s education and prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.8 Working mother:

There were 4 reports (94-96,132) on the association between mother’s work and adolescent overweight and obesity (Table 17) that included 5702 subjects, 2 studies were in males (3835) and 2 in females (1867). The mean prevalence was higher in the group with working mothers (33.1% vs 24.7%). Meta-analysis results of these 4 studies (Figure 16) indicated a statistically significant positive association between mother’s work and odds of overweight and obesity – a pooled odds ratio of 1.51 (95% CI 1.11 to 2.06) with p=0.009 and an I2 = 0%, suggesting low heterogeneity.

Table 17. Working mother and the prevalence (%) of overweight and obesity in Saudi adolescents.

Figure 16. Meta-analysis: Working mothers and prevalence (%) of overweight and obesity in Saudi adolescents.

3.5.9 Health/Label literacy.

No studies were reported about the association between label literacy and the prevalence of overweight and obesity in Saudi adolescents. Therefore, studies are needed.

3.5.10 School food/environment: There was only one report about the association between School environment and the prevalence of overweight and obesity in Saudi adolescents (Table 18). This study included 1495 males and did not show any significant association between the two. More studies are needed to further delineate the effect of this determinant on overweight and obesity in Saudi adolescents.

Table 18. School environment and the prevalence (%) of overweight and obesity in Saudi adolescents

3.5.11 Urbanization:

Only 2 studies about the association between urbanization and the prevalence of overweight and obesity in adolescents in Saudi Arabia were reported and included 2409 subjects (1802 males and 607 females) (Table 19). In the first report, the prevalence of overweight and obesity was significantly higher in urban than rural adolescents (26.9% vs 19.0%, respectively, p=0.011) in both males and females reported together. On the other hand, the second study showed significance only in males (39.4% vs 27.7%, respectively with p=<0.004). These results suggest that Urbanization is possibly associated with overweight and obesity mostly in male adolescents. More studies are needed to further delineate the effect of this determinant on overweight and obesity in Saudi adolescents.

Table 19. Urbanization and the prevalence (%) of overweight and obesity in Saudi adolescents.

Chapter 4 DISCUSSION

Discussion

4.1 Prevalence Rates:

To highlight the magnitude of the problem in Saudi adolescents, prevalence rates of overweight and obesity were evaluated in Saudi adolescents from national (population based) as well as from regional (specific population) studies and to assess the trend of these rates over the reviewed period.

4.1.1 Prevalence Rates of overweight and obesity from national surveys:

It is clear from this review that overweight and obesity in adolescents represent a rising problem in Saudi Arabia. In the first 2002 survey, the prevalence of overweight and obesity in Saudi adolescents started off high, 22.2% in males and 24% in females. With an increase of 39% in males and 36% in females, the prevalence of overweight and obesity in adolescents became 36,2% in males and 38.4% in females during the second survey of 2010. This falls in line with the increasing prevalence of overweight and obesity among many countries in the Middle East and North Africa region, especially in the Gulf region (137). If continued at the same rate, it is expected to have had reached 50.3% in male and 52.2% at the time of this review. It is well known that obesity in adolescents has a serious impact later in life in the form of disturbances in health, including NCDs, and wellbeing, which translates into a significant decrease in life expectancy and quality of life (14, 138). It is likely that the high prevalence of obesity in Saudi adolescents plays a significant role in increasing NCDs in the country (18). Therefore, the management of adolescent obesity in Saudi Arabia is considered as a public health priority. Knowing that the treatment of obesity after it has

46 been established is very difficult, early intervention to prevent obesity in adolescents, by identifying and modifying related social determinants, becomes extremely important (139).

4.1.2 Prevalence Rates of overweight and obesity from regional and multi-regional studies:

Calculated yearly mean prevalence rates were used to assess the trend of overweight and obesity in Saudi adolescents over the reviewed period. Cross-sectional comparisons of the prevalence rates of overweight and obesity from different regional studies are challenging due the use of non- representative samples, differences in age and gender of the samples, and the use of different cutoff reference standards for overweight and obesity in this age group. However, we decided to evaluate the trend of prevalence rates using this method for the following reasons: i- the large number of reviewed studies that were reported from all regions and included a large number of males and females with a ratio close to the that of the total and adolescent populations in Saudi Arabia, ii- the fact that school based adolescent population in Saudi Arabia represents the majority of adolescents in the country, as they exceeded 93% of total adolescent population in the year 2016 (70) for both males and females, and, iii- no national survey of overweight and obesity in adolescents has been reported from Saudi Arabia since 2010.

Calculated yearly mean prevalence rates for the years 2002 and 2010 were in line with the prevalence rates estimated from national surveys for males and females. Also, they continued to increase for males reaching 48.3% in the year 2018, which is in line with the projected prevalence rate from the national studies. These observations suggest that the calculated prevalence rates might be acceptable reflections of the true ones. However, one observation was not consistent with the expected value. The calculated yearly mean prevalence rate for females tended to decrease from the highest value of 42.6 in the year 2010, with the main decrease in 2015 (24.4%) and reaching 27.6% in the year 2017. As an acceptable reflection of true values, this observation could be due to the recent drastic changes in lifestyle and factors/facilities that adolescents, especially females, are exposed to in Saudi Arabia within the past few years (21). Also, it could be a result of the commitment of Saudi Arabia to the 2030 Agenda for Sustainable Development and the

47 achievement of the SDGs at the national level (21). On the other hand, and if it does not represent a reflection of true values, this observation could simply be part of the limitation of using different regional studies for cross-sectional estimation and comparisons of the prevalence of overweight and obesity in adolescents that was used. The only clear answer to this observation can come from a national population-based survey, which is expected in the near future.

4.2 Social determinants of overweight and obesity in adolescents:

This review also aims to look at the problem of overweight and obesity in Saudi adolescents from a behavioral and social standpoint by identifying and constructing an ecological model for social determinants of overweight and obesity in adolescents and discussing them in relation to the Saudi setting.

4.2.1 Identifying and constructing an ecological model:

Social determinants of overweight and obesity are reported in the literature either separately or in small groups. These are usually and factors that can influence body weight (those related to physical activity or diet) as well as potential causes or preventive aspects of overweight and obesity. We extracted from the literature social determinants of overweight and obesity that are related to adolescents (section 1.5.5-1.5.11) as well as to the fast-growing economies of Saudi Arabia (such as large household income, significant modernization, high degree of urbanization …etc.). We grouped these determinants of overweight and obesity in adolescents in an ecological model (Figure 3) to show their relation to the categories of social determinants of health that include; age, sex and constitutional characteristics, individual lifestyle factors, social and community networks, norms and networks, living and working conditions and socioeconomic, cultural and environment conditions. This model can serve as a useful exploratory tool to help the investigation of the multifaceted etiology of adolescent overweight and obesity and facilitate the development of effective intervention and prevention programs.

4.2.2 Determinants of overweight and obesity in Saudi adolescents:

4.2.2.1 Diet patterns/contents:

The fast-growing economy has led to clear changes in eating habits and patterns of food consumption among adolescents in Saudi Arabia and the Gulf Region. (96,140). These changes included eating for pleasure and not only for nourishment, increasing daily consumption of fat and decreasing energy expenditure (96), shifting from traditional healthy food, that consists of whole grains, vegetables, fruits with small amounts of meat and fat, to western fast food that is high in sugar, salt and saturated fat and low in fiber, consuming more unhealthy snacks, soft drinks and other sugar-sweetened beverages (141,142). WHO Member States have agreed to reduce the global population’s intake of salt by 30% and halt the rise in diabetes and obesity in adults and adolescents as well as in childhood overweight by 2025 (143). All reviewed reports on diet patterns and contents and overweight and obesity in Saudi adolescents (90,96,110,124,130) (Table 9-A and B) demonstrated a statistically significant (p=0.02) positive association between fast food and soft drink consumption 2-4 times/week and skipping breakfast lower vegetable intake (<3 times /week) and odds of overweight and obesity. Low interstudy heterogeneity was noted (I2 = 35%). These results indicate that diet patterns and contents are suitable targets for the intervention and prevention of overweight and obesity in Saudi adolescents.

4.2.2.2 Physical activity:

With the recent socioeconomic development, adolescents became less physically active and the activity levels required for work and transportation were significantly reduced. In addition, several environmental factors linked to urbanization, such as high-density traffic, limited sport/recreation facilities, lack of parks and sidewalks, air pollution, fear of crime and violence in outdoor areas discouraged adolescents from becoming more active (33). Therefore, increasing physical activity is a social, not just an individual problem and it demands a population-based, multi-sectoral, multi- disciplinary, and culturally relevant approach (33). Although the WHO recommends 60 minutes of moderate- to vigorous-intensity physical activity daily for young people ages 5 to 17, >80% of the world's adolescent population is insufficiently physically active. (33). The 2030 SDGs provides an opportunity to refocus and renew efforts at promoting physical activity. The WHO is working on a new global action plan, which aims to benefit from the contributions of all relevant sectors,

49 including, environment, education, health, sports and technology to accelerate progress in achieving the global voluntary NCD targets set by the World Health Assembly for 2025 (144).

Three out of the 7 reports (90,124,132), 2 in males and one in females, on physical activity and overweight and obesity in Saudi adolescents showed no statistically significant association between less physical activity/week and odds of overweight and obesity. Significant interstudy heterogeneity was noted (I2 = 88%) owing to differences in evaluation parameters. On the other hand, one other report (110) used total METS (minute/week) for the evaluation and demonstrated a positive association between less physical activity/week (p=<0.05) in both males and females (Table 9-B). Three other reports showed that a high % of adolescents never exercise, mainly females (reached 100% in one study) (Table 9-B). These results might not reflect the current status because of the recent drastic changes in lifestyle and factors/facilities that adolescents, especially females, are exposed to in Saudi Arabia within the past year (21). The other 2 reports (Table 10-B) showed that the number of hours per day of TV/Computer screen time spent in overweight and obese Saudi adolescents was higher than that spent by normal weight adolescents, however only one of these 2 studies showed significant results. Results from this review suggest that physical activity might be a suitable target for the intervention and prevention of overweight and obesity in Saudi adolescents and that more new studies with standardized protocols are needed.

4.2.2.3 Sedentary behavior factors:

With the improvements in the socioeconomic status in Saudi Arabia, sedentary behaviors have increased dramatically among adolescents and they include watching TV, using computer, playing video games and surfing the internet, and use of "passive" modes of transport (36, 37). It was found that each additional hour of sedentary activity per day, in the form of watching television hours, increases the prevalence of obesity by 2% (145). The increase in time spent with sedentary activity leads to a decrease in the time spent in physical activity and an increase in consumption of salty snacks, sweets, and sweetened cereals and beverages (146).

Four studies (119,124,130,133) on TV/ computer screen time and overweight and obesity in Saudi adolescents (Table 10-A) demonstrated a statistically significant (p= <0.002) positive association between longer TV/computer screen time and odds of overweight and obesity. Low interstudy

50 heterogeneity was noted (I2 = 38%). The other 2 reports (Table 10-B) showed that the number of hours per day of TV/Computer screen time spent overweight and obese Saudi adolescents was higher than that spent by normal weight adolescents, however only one of these 2 studies showed significant results. There were no studies about the effect of rapidly growing social media, playing video games and surfing the internet, as well as the use of "passive" modes of transport, in relation to adolescent overweight and obesity in Saudi Arabia. Studies are needed to properly evaluate the effect of sedentary behavior factors on overweight and obesity in Saudi adolescents. Results from this review suggest that sedentary behavior factors, in the form of TV/Computer screen time, can be suitable targets for the intervention and prevention of overweight and obesity in Saudi adolescents and that more new studies about other sedentary behavior factors are needed.

4.2.2.4 Sleep pattern/Stress/Smoking:

Studies have shown that sleep is an important regulator of many biological and physiological functions, such as appetite, energy balance, and weight maintenance, and that control of body weight and nutrient metabolism are greatly affected by the number of hours of sleep (40,44). Both short and long periods of habitual sleep are linked to obesity (45). Short sleep duration can lead to a reduction in the satiety hormone leptin and an increase in the hunger hormone ghrelin causing an increase in appetite (44,45). The fast-growing economies and rapid advancement in technology have resulted in extensive television viewing and use of other electronic media (computers, videogames and the internet), which made short sleep duration a major problem among adolescents. There were only 2 reports (101,110) in male subjects about the association between sleep pattern and the prevalence of overweight and obesity in Saudi adolescents (Table 11). Both studies showed statistically significant (p=<0.005 and <0.006) positive associations between decreased number of sleeping hours (<7 and <8 hours) and overweight and obesity. More studies with fixed parameters are needed to properly evaluate the effect of this determinant on overweight and obesity. Results from this review suggest that sleep pattern can be a suitable target for the intervention and prevention of overweight and obesity in Saudi adolescents and that more studies are needed.

Adolescence is the critical period during which health habits, including eating behaviors, physical activity and smoking are established. In a follow-up study in adolescents, smoking was reported as a risk factor for adulthood abdominal obesity in both males and females and for overweight only in females (51). Mechanisms of the possible causal link between smoking and body weight are not clear. Changes in cortisol metabolism and/or psychosocial stress related to smoking might represent a possible explanation (52-54). Only one study (132) was reported about the association between smoking and the prevalence of overweight and obesity in Saudi adolescents. Because of the small numbers in this study, the association between smoking and the prevalence of overweight and obesity in Saudi adolescents cannot be evaluated. With a tobacco epidemic being on the rise in Saudi adolescents (136), more current studies are needed to further delineate the effect of smoking on overweight and obesity in Saudi adolescents.

Evidence is accumulating that stress is linked to the development of obesity via the chronic increase of cortisol (the glucocorticoid stress hormone) (46). In a modern society, the high prevalence of obesity goes hand in hand with chronic stress, consuming food containing large amounts of sugar and decreased hours of sleep, suggesting a close relation between these conditions (47,48) that are common among adolescents. Also, recent studies in adolescents reported a bidirectional (cause and effect) relationship between eating disturbances and depression and a high rate of anxiety disorders among obese adolescents (49-50). In this review, no studies were reported about the association between stress and the prevalence of overweight and obesity in Saudi adolescents. Stress may be used as a target for the intervention and prevention of overweight and obesity in Saudi adolescents, however, studies are needed.

4.2.2.5 Family history of obesity/Family size:

52 be related to the mentioned family factors as well as to genetic factors. The association between family history of obesity and the prevalence of overweight and obesity was reported in 2 studies (90,130) (Table 13). Both concluded a significant association between overweight and obesity and a positive family history of obesity with p-value of <0.05. However, no values of prevalence were given in the second study. Therefore, family history of obesity may be used as a target for the intervention and prevention of overweight and obesity in Saudi adolescents, however, more studies are needed to properly evaluate the effect of this determinant.

Studies suggest that family size also has a role in the development of overweight and obesity. The higher the number of siblings the lower the BMI and the lower the chance of overweight and obesity in a family, which could be due to family mealtimes, reduced maternal work and less eating out. Also, children with siblings watch less television and have healthier diets (57). There were 2 reports (96,133) about the association between family size and the prevalence of overweight and obesity in Saudi adolescents (Table 12). The parameter used for the evaluation of the effect of family size on overweight and obesity was > 6 in the first study and > 8 in the second. A family size >6 or >8 was negatively associated with obesity with a reported (p= <0.001 and 0.05, respectively). Therefore, family size may be used as a suitable target for the intervention and prevention of overweight and obesity in Saudi adolescents, however, more studies with fixed parameters are needed to properly evaluate the effect of this determinant in this population.

4.2.2.6 Household income (Economics/Social class):

53 by race (61). The association between economic/social class and the prevalence of overweight and obesity in adolescents was reported in 7 studies (92,95,97,98,118,132,133) (Table 14). These studies indicated a statistically significant (p= <0.0003) positive association between higher economic/social class and odds of overweight and obesity. However, significant interstudy heterogeneity was noted (I2 = 71%) owing to differences in evaluation parameters. Therefore, results from this review suggest that economic/social class may be used as a suitable target for the intervention and prevention of overweight and obesity in Saudi adolescents and that more new studies with standardized parameters are needed.

4.2.2.7 Parental Education:

Although parental education is supposed to improve awareness of all family members on healthy food selections (62), recent studies suggest that it is associated with increased rate of overweight in children and adolescents and in lower income countries (63). This association seems to vary according to the developmental stage of different countries. In higher economic status countries, like paternal rather than maternal higher education is associated with more positive influence on lowered child overweight. This might be due to the fact that educated mothers are usually working and bringing more income, both of which are associated with overweight and obesity in children and adolescents. On the other hand, a more negative influence of maternal higher education on increased child overweight is observed in lower economic status countries (63). The association between mother education and the prevalence of overweight and obesity in adolescents was reported in 9 studies (92,95-97,108,118,130,132,133) (Table 15). These indicated a statistically significant (p=0.04) positive association between mothers with the highest level of education and odds of overweight and obesity. However, significant interstudy heterogeneity was noted (I2 = 72%) owing to differences in evaluation parameters. On the other hand, the association between father education and the prevalence of overweight and obesity in Saudi adolescents was reported in 6 studies (96,97,108,118,132,133) that indicated a statistically significant (p=0.0005) positive association between fathers with the highest level of education and odds of overweight and obesity (table 16). Low interstudy heterogeneity was noted (I2 = 10%). Therefore, results from this review suggest that parental education can be used as a suitable target for the intervention and prevention of

54 overweight and obesity in Saudi adolescents and that more studies, mainly about mother education, are needed.

4.2.2.8 Working mother:

Studies have shown that when both parents are working away from their children, there is a high chance that their children will develop overweight and obesity (64-66). Working mothers spend less time on preparing food for their children who will eat more restaurant made fast food meals, which are known to increase of overweight and obesity in children and adolescents (64,65). In addition, there will be less supervision and more sedentary behaviors (watching television, using computer, playing passive video games and surfing the internet) will dramatically increase among children and adolescents, which will add to the problem (66). It was estimated that 10% of the rise in childhood obesity is related to maternal employment (67) however, recent studies showed that the size of the problem is much more than that (68). There were 4 reports (94-96,132) on the association between mother’s work and adolescent overweight and obesity (Table 17). These studies indicated a statistically significant (p=0.009) positive association between working mother and odds of overweight and obesity in Saudi adolescents. A very low interstudy heterogeneity was noted (I2 = 0%). Accordingly, results from this review suggest that parental education can be used as a suitable target for the intervention and prevention of overweight and obesity in Saudi adolescents.

4.2.2.9 Health/label literacy:

Low food label literacy can lead to an increased risk of obesity, high blood lipids, and high blood pressure (69). Also, low level of health literacy is related to many aspects of adolescence health including their body weight. Studies have shown that low health literacy is significantly associated with overweight or obesity in adolescents, which should be considered in all strategies combating adolescence weight problem (70,71). No studies were reported about the association between label literacy and the prevalence of overweight and obesity in Saudi adolescents. Therefore, studies are needed.

4.2.2.10 School food/environment:

School food represents 35-47% of the daily intake of children and adolescents (72). While at school, students are exposed to all types of unhealthy food (such as French fries, chips, pizza, and candies) and beverages (mainly sugar-sweetened beverages) (73-76), all of which can lead to high rate of overweight and obesity in adolescents. There was only one report about the association between School environment and the prevalence of overweight and obesity in Saudi adolescents (Table 18). This study did not show any significant association between the two. More studies are needed to further delineate the effect of this determinant on overweight and obesity in Saudi adolescents.

4.2.2.11 Urbanization:

Recent studies suggest that rapid urbanization accounts for significant shifts in dietary patterns and for physical activity (77). Several environmental factors are linked to urbanization, such as high- density traffic, limited sport/recreation facilities, lack of parks and sidewalks, air pollution, fear of crime and violence in outdoor areas discouraged adolescents from becoming more active (33). Only 2 studies about the association between urbanization and the prevalence of overweight and obesity in adolescents in Saudi Arabia were reported (Table 20). In the first report, the prevalence of overweight and obesity was significantly higher in urban than rural adolescents (26.9% vs 19.0%, respectively, p= 0.011) in both males and females reported together. On the other hand, the second study showed significance only in males (39.4% vs 27.7%, respectively with p=<0.004). These results suggest that urbanization is possibly associated with overweight and obesity mostly in male adolescents. Therefore, results from this review suggest that parental education can be used as a suitable target for the intervention and prevention of overweight and obesity in Saudi adolescents and that more studies are needed.

4.3 Social Policy and Structural Measures:

Although many of the reviewed reports highlighted the problem of overweight and obesity in Saudi adolescents, no prevention or management intervention has been reported. This review provided a

56 summary of current evidence regarding most of the possible social determinants of overweight and obesity in Saudi adolescents. A comprehensive understanding of these social determinants and their influences on overweight and obesity in this population are crucial to developing prevention and management interventions to support Saudi adolescents towards healthy outcomes. It is important to note that most of these determinants are modifiable and that implementing intervention programs have helped in reducing and slowing obesity rates in some Western countries (147--149). Therefore, it is crucial to design multifaceted, national, obesity prevention programs with special focus on adolescents.

4.3.1 Types of interventions to tackle obesity:

No single intervention can halt the advance of the epidemic of obesity. To challenge adolescent’s obesity successfully requires countering the obesogenic environment and addressing vital elements in the life course through coordinated, multi-sectoral action that is held to account. Interventions to tackle adolescent’s obesity can be integrated into and build upon existing national plans, policies and programs.

Categories of policy action usually include focused initiatives, which are interventions aimed directly at tackling obesity or a particular at-risk group (in this case adolescents). The impact of individual interventions or focused initiatives in isolation is likely to be small. The combined impact might be strengthened by implementing a range of policies that act as ‘enablers’ or ‘amplifiers’ of the core interventions. Alone, such policies have little or no direct impact on obesity but may magnify the impact of other initiatives. Enablers are policies that act as essential underpinning elements of a comprehensive strategy, notably action on education and skills (necessary but insufficient). Other policies may amplify impact, usually by shifting wider perceptions of obesity-related issues and can drive social or cultural norms in a direction that elicits greater support for and adoption of other initiatives (cannot act if the other elements are not in place. Figure 17 shows an example of different types of interventions to tackle obesity (150).

Figure 17. Different types of interventions to tackle obesity.

4.3.2 WHO Recommendations on policy action and interventions:

Recognizing that progress in tackling obesity in infants, children and adolescents has been slow and inconsistent, the WHO established the Commission on Ending Childhood Obesity in 2014 to review, build upon and address gaps in existing mandates and strategies in order to prevent infants, children and adolescents from developing obesity. In 2016, The report of the Commission presented a comprehensive, integrated package of recommendations to guide countries to address childhood obesity. The recommendations related to obesity in adolescents are summarized as follows:

1- Implement comprehensive programs that Promote the intake of healthy foods and reduce the intake of unhealthy foods and sugar sweetened beverages by adolescent:

1.1- Ensure that appropriate and context-specific nutrition information and guidelines for both adults and children are developed and disseminated in a simple, understandable and accessible manner to all groups in society.

1.2- Implement an effective tax on sugar-sweetened beverages.

1.3- Implement the set of recommendations on the marketing of foods and non-alcoholic beverages to children1 to reduce the exposure of children and adolescents to, and the power of, the marketing of unhealthy foods.

1.4- Develop nutrient profiles to identify unhealthy foods and beverages.

1.5- Establish cooperation between Member States to reduce the impact of cross-border marketing of unhealthy foods and beverages.

1.6- Implement a standardized global nutrient-labelling system.

1.7- Require settings such as schools, child-care settings, children’s sports facilities and events to create healthy food environments.

1.8- Increase access to healthy foods in disadvantaged communities.

2- Implement comprehensive programs that Promote physical activity and reduce sedentary behaviors in adolescents:

2.1- Provide guidance to children and adolescents, their parents, carers, teachers and health professionals on healthy body size, physical activity, sleep behaviors and appropriate use of screen-based entertainment.

2.2- Ensure that adequate facilities are available on school premises and in public spaces for physical activity during recreational time for all adolescents (including those with disabilities), with the provision of gender-friendly spaces where appropriate.

3- Implement comprehensive programs that promote healthy school environments, health and nutrition literacy and physical activity among school-age adolescents:

3.1- Establish standards for meals provided in schools, or foods and beverages sold in schools that meet healthy nutrition guidelines.

3.2- Eliminate the provision or sale of unhealthy foods, such as sugar-sweetened beverages and energy-dense, nutrient-poor foods, in the school environment.

3.3- Ensure access to potable water in schools and sports facilities.

3.4- Require inclusion of nutrition and health education within the core curriculum of schools.

3.5- Improve the nutrition literacy and skills of parents and carers.

3.6- Make food preparation classes available to children, their parents and carers.

3.7- Include quality physical education in the school curriculum and provide adequate and appropriate staffing and facilities to support this.

4- Provide family-based, multicomponent services on lifestyle weight management for adolescents who are obese:

4.1- Develop and support appropriate weight management services for children and adolescents who are overweight or obese that are family-based, multicomponent (including nutrition, physical activity and psychosocial support) and delivered by multi-professional teams with appropriate training and resources, as part of universal health coverage.

4.3.3 Relevant policies in Saudi Arabia:

Saudi Arabia has witnessed a huge health expenditure accompanied by significant improvement in its health indicators for both curative and public health services. Hundreds of hospitals and primary health care centers were established and many public health programs, such as immunization, health education and environmental sanitation, have been implemented and a good number of policies have been formulated (152). However, a significant weakness in public health services is still noticed as health plans and expenditure in the health system are mainly concentrating on the curative aspects and allocating most jobs for curative care (152). As a result, health-related policies, including those related to adolescents, in Saudi Arabia are affected. Most of the adolescent general and topic-specific policies are not implemented (Figure 17) (153).

Figure 17. General and topic-specific policies related to Saudi adolescents. (Ref. 153)

In addition, policies directly targeting social determinants of overweight and obesity in adolescents in Saudi Arabia are almost non-existent. Policies targeting specific determinants, such as standards for health promoting schools and prohibition of tobacco sales to minors, are the only somewhat related policies (153). However, these policies still need improvement in terms of implementation and compliance (154). A recent study investigated the compliance with school nutrition policy in Saudi Arabia and reveled that meals offered in Saudis schools come prepackaged with minimal cooking in schools. From a calorie perspective, there was not a significant difference between the food allowed and food not allowed. For the Saudi policy, 94.7% of the schools scored in between category 2 and 3 (moderate compliance). For the Institute of Medicine (IOM) standards, 96.1% of

61 the schools scored in category 1 (low alignment). The study concluded, “While the Saudi policy is clear on what should not be served in school cafeterias, it fails to provide guidance on what must be served to improve the nutritional value of meals provided” (154).

4.4 Strengths and Limitations

4.4.1 Strengths:

This study is the largest systematic review looking specifically into adolescents in Saudi Arabia within the period until December 31, 2018. The large study population of 97,666 subjects is a notable strength and the ratio of males/females (56.9%/43.1%) within this study is reflective of the adolescent population (male/female = 51.9%/49.1%) and the total population (male/female = 57.4%/42.6%) of Saudi Arabia. This systematic review is the first to look at the problem of overweight and obesity in adolescents from behavioral and social standpoint by identifying and constructing an ecological model for their social determinants discussing them in relation to the Saudi setting.

4.4.2 Limitations:

Ethnicity was not deeper looked into in the studies reviewed. Some “Saudi” adolescents may have been from different ethnic backgrounds which may have an impact on their overall genetic dispositions as some ethnicities demonstrate a higher risk for developing overweight and/or obesity. The adolescent age categories were not specified in the reviewed studies (younger vs older adolescents), which limits the effect of some determinants as the adolescent’s body functions and metabolism differs in those two periods. The variability in the type of cut-offs used to define obesity in the studies reviewed (WHO, CDC, IOTF) limits the comparison between these studies. The small number of some studies per determinant is considered a limitation of this review, as it did not allow further analysis, such as, performing meta-analysis in these small studies. The variation in the parameters used for the evaluation of the effects of some determinants on overweight and obesity, such as, type and duration of physical activity, family size, duration of screen time, duration of sleep time etc. Some major social determinants identified in this review

62 had no studies that evaluated their relation to overweight and obesity in Saudi adolescent, such as, social media, label literacy, and stress. Recent drastic changes in lifestyle and factors/facilities that adolescents are exposed to in Saudi Arabia within the past year may play a large role in influencing the effect of some determinants mentioned in this review. However, this can be considered a strength, as the results of this analysis are up to the date right before these changes occurred and can serve as a good baseline for future studies.

4.5 Conclusions:

This review clearly demonstrates that the prevalence of overweight and obesity among adolescents is a major public health problem in Saudi Arabia and is growing at an alarming rate, and that social determinants play a significant role in this problem and should be considered in all strategies targeting it. Policies directly targeting social determinants of overweight and obesity in adolescents in Saudi Arabia are almost non-existent. The constructed ecological model for social determinants of overweight and obesity in adolescents, reported in this review, can serve as a useful exploratory tool to help the investigation of the multifaceted etiology of adolescent overweight and obesity and facilitate the development of effective intervention and prevention programs.

References

1. Obesity and overweight (2017) http://www.who.int/news-room/fact- heets/detail/obesity -and-overweight, accessed on April 12, 2019.

2. Defining Childhood Obesity- BMI for Children and Teens (2016). https://www.cdc.gov/obesity/childhood/defining.html accessed on April 12, 2019.

3. World Health Organization: Global Health Observatory (GHO) data, NCD mortality and morbidity. https://www.who.int/gho/ncd/mortality_morbidity/en/, accessed on Aug. 5, 2019.

4. UN: About the Sustainable Development Goals. https://www.un.org/sustainabledevelopment/sustainable-development-goals/, accessed on Aug. 5, 2019.

5. Klein JD, Alden ER. Children, gender, education, and health. Pediatrics 2017; 140 (1); e20171322 doi: 10.1542/peds.2017-1322

6. Patton, GC, Sawyer SM2, Santelli JS, et al. Our future: a Lancet commission on adolescent health and wellbeing. Lancet 2016; 387:2423–2478.

7. Patton GC, Coffey C, Carlin JB, et al. Overweight and obesity between adolescence and young adulthood: a 10-year prospective cohort study. J Adolesc Health. 2011; 48:275– 80.

8. GBD 2016 Healthcare Access and Quality Collaborators. Worldwide trends in body- mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults. Lancet. 2017; 390: 2627–2642.

9. Simmonds M, Llewellyn A, Owen CG, Woolacott N. Predicting adult obesity from childhood obesity: a systematic review and meta-analysis. Obes Rev. 2016;17(2):95– 107.

10. Bhutta ZA. and Zlotkin S. Why Adolescent Health and Why Now? SickKids Centre for Global hild Health (2014). https://www.huffingtonpost.com /sickkids-centre-for- global-child-health/why-adolescent-health-and_b_4789639.html, accessed on April 12, 2019.

11. United Nations Secretary-General. The global strategy for women’s, children’s and adolescent’s health (2016–2030): survive thrive transform. 2015. http://www.who.int/life- course/partners/global-strategy/globalstrategyreport2016-2030-lowres.pdf?ua=1, accessed on April 5, 2019.

12. Patton GC, Olsson CA, Skirbekk V, et. al. Adolescence and the next generation. Nature. 2018; 554:458-466. doi: 10.1038/nature25759

13. Murray CJ, Barber RM, Foreman KJ, et al. Global, regional, and national disability- adjusted life years (DALYs) for 306 diseases and injuries and healthy life expectancy (HALE) for 188 countries, 1990–2013: quantifying the epidemiological transition. Lancet. 2015; 10009:2145–91.

14. Sawyer SM, Afifi RA, Bearinger LH, et al. Adolescence: a foundation for future health. Lancet. 2012; 379:1630–40. [PubMed: 22538178]

15. Jamison DT, Summers LH, Alleyne G, et al. Global health 2035: a world converging within a generation. Lancet. 2013; 382:1898–955. [PubMed: 24309475]

16. McKinsey Global Institute -Author. Saudi Arabia beyond oil: The investment and productivity transformation. Riyadh, Saudi Arabia. 2015: https://www.mckinsey.com

17. David C.W. Lau, James D. Douketis, Katherine M. Morrison, Irene M. Hramiak, Arya M. Sharma, Ehud Ur, for members of the Obesity Canada Clinical Practice Guidelines Expert Panel. 2006 Canadian clinical practice guidelines on the management and prevention of obesity in adults and children. CMAJ 2007;176:S1-13 doi: 10.1503/cmaj.061409.

18. World Health Organization: Prevention and Control of Noncommunicable Diseases in the Kingdom of Saudi Arabia: the case for Investment. United Nations Interagency Task Force on the prevention and control of NCDs and WHO. 2017; P 2-9.

19. Mokdad AH, Tuffaha M, Hanlon M, El Bcheraoui C, Daoud F, Al Saeedi M, Alrasheedy AA, Al Hussein MA, Memish ZA, Basulaiman M, AlMazroa MA, Al Rabeeah AA. Cost of diabetes in the Kingdom of Saudi Arabia, 2014. J Diabetes & Metab. 2015; 6:575. doi:10.4172/2155-6156.1000575.

20. World Health Organization: Global Coordination Mechanism on the Prevention and Control of NCDs. NCD and Youth. https://www.who.int/global-coordination- mechanism/ncd-themes/ncd-and-youth/en/, accessed on Aug. 11, 2019.

21. Towards Saudi Arabia’s sustainable tomorrow. First Voluntary National Review2018. https://sustainabledevelopment.un.org/content/documents/20230SDGs_English_Repor t972018_FINAL.pdf, accessed on Aug. 12, 2019.

22. Viner RM, Ozer EM, Denny S, et al. Adolescence and the social determinants of health. Lancet. 2012; 379:1641–1652.

23. Dahlgren G and Whitehead M. WHO: European strategies for tackling social inequities in health: Levelling up Part 2. http://www.euro.who.int/ data/assets/pdf_file/0018/103824/E89384.pdf, accessed on Aug. 12, 2019.

24. Berkman LF, Glass T (2000). Social integration, social networks, social support, and health. In: Berkman LF, Kawachi I, eds. Social epidemiology. New York, Oxford University Press: 137–173.

25. Wilkinson RG. The impact of inequality: how to make sick societies healthier. New York, NY: The New Press. 2005. ISBN: 1-56584-925-6.

26. World Health Organization: World health report 2002. Reducing risks, promoting healthy life. Geneva, World Health Organization 2002. https://www.who.int/whr/2002/en/whr02_en.pdf? Ua =1, accessed on Aug. 12, 2019.

27. Costa G et al. Italian case study. In: Health for All? A critical study of policies in seven European countries. Hogstedt C. Backhans M. Lundgren B. Moberg H. (eds). Stockholm, National Institute of Public Health. 2006.

28. Yach D, Stuckler D, Brownell KD (). "Epidemiologic and economic consequences of the global epidemics of obesity and diabetes". Nat. Med. 2006;12: 62–66.

29. Hill JO, Wyatt HR, and Peters, JC. Energy Balance and Obesity. Circulation. 2012; 126(1): 126–132.

30. World Health Organization: Nutrition. Healthy diet, act sheet No. 394. Updated August 2018 https://www.who.int/nutrition/publications/nutrientrequirements/healthydiet_ factsheet/en/, accessed on Aug. 9, 2019

31. World Health Organization: Global Strategy on Diet, Physical Activity and Health. Physical Activity. https://www.who.int/dietphysicalactivity/pa/en/, on Aug. 7, 2019.

32. Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee Report; U.S. Department of Health and Human Services: Washington, DC, USA, 2008.

33. World Health Organization: Global Strategy on Diet, Physical Activity and Health. Physical activity and young people. https://www.who.int/dietphysicalactivity/factsheet_ young_people/en/, accessed on Aug. 7, 2019.

34. Sedentary Behaviour and Obesity Expert Working Group. Sedentary Behaviour and Obesity: Review of the Current Scientific Evidence; Department of Health: London, UK, 2010.

35. Ekelund, U.; Anderssen, S.A.; Froberg, K.; Sardinha, L.B.; Andersen, L.B.; Brage, S.; European Youth Heart Study Group. Independent associations of physical activity and cardiorespiratory fitness with metabolic risk factors in children: The European Youth Heart Study. Diabetologia 2007, 50, 1832–1840.

36. Hancock J, Inchley J. and Health Behaviour In School-Aged Children (HBSG)Physical Activity Focus Group. Sedentary behaviour. http://www.hbsc.org/publications/ factsheets/Sedentary-Behaviour-english.pdf, accessed on Aug. 10, 2019.

37. World Health Organization: Global strategy on diet, physical activity and health physical inactivity: a global public health problem. https://www.who.int/ dietphysicalactivity/factsheet_inactivity/en/ , accessed on Aug. 10, 2019.

38. Chen X, Beydoun MA, Wang Y. Is sleep duration associated with childhood obesity? A systematic review and meta-analysis. Obesity (Silver Spring) 2008;16:265–274.

39. Magee CA, Iverson DC, Huang XF, Caputi P. A link between chronic sleep restriction and obesity: methodological considerations. Public Health 2008;122:1373–1381.

40. Lumeng JC, Somashekar D, Appugliese D et al. Shorter sleep duration is associated with increased risk for being overweight at ages 9 to 12 years. Pediatrics 2007;120:1020–1029.

41. Nixon GM, Thompson JM, Han DY et al. Short sleep duration in middle childhood: risk factors and consequences. Sleep 2008; 31:71–78.

42. Al Mamun A, Lawlor DA, Cramb S et al. Do childhood sleeping problems predict obesity in young adulthood? Evidence from a prospective birth cohort study. Am J Epidemiol 2007;166:1368–1373.

43. Taheri S. The link between short sleep duration and obesity: we should recommend more sleep to prevent obesity. Arch Dis Child 2006;91:881–884.

44. Taheri S, Lin L, Austin D, Young T, Mignot E. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Med 2004;1:e62.

45. Horne J. Short sleep is a questionable risk factor for obesity and related disorders: statistical versus clinical significance. Biol Psychol 2008;77:266–276.

46. Fardet L, Feve B. Systemic glucocorticoid therapy: a review of its metabolic and cardiovascular adverse events. Drugs. 2014;74(15):1731–1745.

47. 2-Knutson KL, Van Cauter E, Rathouz PJ, DeLeire T, Lauderdale DS. Trends in the prevalence of short sleepers in the USA: 1975- 2006. Sleep. 2010;33(1):37–45

48. van Rossum EF. Obesity and cortisol: new perspectives on an old theme. Obesity (Silver Spring). 2017;25(3):500–1. https://doi.org/ 10.1002/oby.21774.

49. Rawana JS, Morgan AS, Nguyen H, Craig SG. The relation between eating- and weight- related disturbances and depression in adolescence: A review. Clin Child Fam Psychol Rev. 2010;13:213–230.

50. Goldfield GS, Moore C, Henderson K, Buchholz A, Obeid N, Flament MF. Body dissatisfaction, dietary restraint, depression, and weight status in adolescents. J Sch Health. 2010;80:186–192.

51. Saarni SE, Pietiläinen K, Kantonen S, Rissanen A, Kaprio J. Association of smoking in adolescence with abdominal obesity in adulthood: a follow-up study of 5 birth cohorts of Finnish twins. Am J Public Health. 2009 Feb;99(2):348-54. doi: 10.2105/AJPH.2007.123851.

52. Rohleder N, Kirschbaum C. The hypothalamicpituitary-adrenal (HPA) axis in habitual smokers. Int J Psychophysiol. 2006;59(3):236–243.

53. Bjorntorp P, Rosmond R. Obesity and cortisol.Nutrition. 2000;16(10):924–936.

54. Bjorntorp P. Do stress reactions cause abdominal obesity and comorbidities? Obes Rev. 2001;2(2):73–86.

55. Budd GM, Hayman LL. Addressing the childhood obesity crisis. Am J Matern Child Nurs. 2008;33:113–7.

56. Moens E, Braet C, Bosmans G, Rosseel Y. Unfavourable family characteristics and their associations with childhood obesity: A cross-sectional study. Eur Eat Disord Rev. 2009;17:315–23.

57. Datar A. The more the heavier? Family size and childhood obesity in the U.S. Soc Sci Med. 2017;180:143-151. doi: 10.1016/j.socscimed.2017.03.035.

58. Hruschka DJ () Do economic constraints on food choice make people fat? A critical review of two hypotheses for the poverty–obesity paradox. Am J Hum Biol 2012;24(3):277–285

59. Subramanian SV, Perkins JM, Özaltin E, Davey Smith G () Weight of nations: a socioeconomic analysis of women in low– to middle–income countries. Am J Clin Nutr 2011;93:413–442.

60. Hill S, Proffitt Leyva R, DelPriore D. Predicting human adiposity—sometimes—with food insecurity: Broaden the model for better accuracy. Behav Brain Sci 2017;40:e119

61. Ogden CL, Carroll MD, Fakhouri TH, et, al. Prevalence of Obesity Among Youths by Household Income and Education Level of Head of Household — United States 2011– 2014. Centers for Disease Control Mortality and morbidity weekly reports. 2018; 67P:86–189.

62. Smith AJ, Pak E, Abreu CM; et. al. Parental education level and childhood obesity. JIM. 2018;66:A 64.DOI: 10.1136/jim-2017-000663.5.

63. Muthuri SK, Onywera VO, Tremblay MS. et. al. Relationships between Parental Education and Overweight with Childhood Overweight and Physical Activity in 9–11

Year Old Children: Results from a 12-Country Study. PLoS One. 2016;11: e0147746. 24. doi: 10.1371/journal.pone.0147746. PMCID: PMC4996501.

64. Cawley, J., & Liu, F. (2012) Maternal employment and childhood obesity: A search formechanisms. Economics and Human Biology, 10, 352-364.

65. Lin, B.; Guthrie, J.; Frazao, E. Away-from-Home Foods Increasingly Important to Quality of American Diet; U.S.Department of Agriculture, Economic Research Service: Washington, DC, USA, 1999; p. 749.

66. Story M, Neumark-stainzer D, French S. Individual and environmental influences on adolescent eating behaviours. J Am Diet Assoc. 2002;102:S40–51.

67. Courtemanche, C. Longer hours and larger waistlines: The relationship between work hours and obesity. Forum for Health Economics and Policy, 2009; 12 (2), Article 5.

68. Courtemanche C, Tchernis R, Zhou X. Parental work hours and childhood obesity: evidence using instrumental variables related to sibling school eligibility, IZA Institute of Labor Economics 2017: IZA DP No. 10739.

69. Rimpeekool W, Yiengprugsawan V, Kirk M, Banwell C, Seubsman SA, Sleigh A. Nutrition label experience, obesity, high blood pressure, and high blood lipids in a cohort of 42,750 Thai adults. PLoS One. 2017 Dec 13;12(12):e0189574. doi: 10.1371/journal.pone.0189574.

70. Lam LT, Yang L. Is low health literacy associated with overweight and obesity in adolescents: an epidemiology study in a 12–16 years old population, Nanning, China, 2012. Arch Public Health. 2014; 72(1): 11. doi: 10.1186/2049-3258-72-11. PMCID: PMC3994214.

71. Cha ES, Kim KH, Lerner HM, et al. Health Literacy, Self-efficacy, Food Label Use, and Diet in Young Adults. Am J Health Behav. 2014; 38: 331–339. doi: 10.5993/AJHB.38.3.2.

72. Briefel RR, Wilson A, Gleason PM: Consumption of low-nutrient, energy-densefoods and beverages at school, home, and other locations among school lunch participants and nonparticipants. J Am Diet Assoc 2009, 109:S79–S90.

73. Fox MK, Dodd AH, Wilson A, Gleason PM: Association between school food environment and practices and body mass index of US public school children. J Am Diet Assoc 2009, 109:S108–S117.

74. Park S, Sappenfield WM, Huang Y, Sherry B, Bensyl DM: The impact of the availability of school vending machines on eating behavior during lunch: the Youth Physical Activity and Nutrition Survey. J Am Diet Assoc 2010, 110:1532–1536.

75. Rovner AJ, Nansel TR, Wang J, Iannotti RJ: Food sold in school vending machines is associated with overall student dietary intake. J Adolesc Health 2011, 48:13–19.

76. Briefel RR, Crepinsek MK, Cabili C, Wilson A, Gleason PM: School food environments and practices affect dietary behaviors of US public school children. J Am Diet Assoc 2009, 109:S91–S107.

77. Sobal J. Commentary: globalization and the epidemiology of obesity. Int J Epidemiol 2001;30:1136-1137.

78. Cole TJ, Bellizzi MC, Flegal KM, et al. Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ. 2000; 320:1240–1243. [PubMed: 10797032].

79. Kuczmarski RJ, Ogden CL, Guo SS, et al. 2000 CDC Growth Charts for the United States: methods and development. Vital Health Stat. 2002; 11:1–190.

80. de Onis M, Onyango AW, Borghi E, et al. Development of a WHO growth reference for school-aged children and adolescents. Bull World Health Organ. 2007; 85:660–667. [PubMed: 18026621.

81. Roberts KC, Shields M, de Groh M, et al. Overweight and obesity in children and adolescents: results from the 2009 to 2011 Canadian Health Measures Survey. Health reports. 2012; 23:37–41. [PubMed: 23061263]

82. Ogden CL, Carroll MD, Kit BK, et al. Prevalence of obesity and trends in body mass index among US children and adolescents, 1999–2010. JAMA. 2012; 307:483–490. [PubMed: 22253364]

83. Moher D, Liberati A, Tetzlaff J, et al.: Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009; 6(7): e1000097.

84. Vandenbroucke JP, von Elm E, Altman DG, Gøtzsche PC, Mulrow CD, Pocock SJ, Poole C, Schlesselman JJ, Egger M; STROBE Initiative. Strengthening the Reporting of Observational Studies in Epidemiology (STROBE): explanation and elaboration. Int J Surg. 2014;12(12):1500-24. doi: 10.1016/j.ijsu.2014.07.014. APubMed PMID: 25046751.

85. Al-Nuaim AR, Bamgboye EA, al-Herbish A. The pattern of growth and obesity inSaudi Arabian male school children. Int J Obes Relat Metab Disord. 1996;20(11):1000-5. PubMed PMID: 8923156.

86. Ghabrah TM, Bahnassy AA, Abalkhail BA, Al-Bar HM, Milaat WA. The prevalence of cardiovascular risk factors among students in jeddah, saudi arabia. J Family Community Med. 1997;4(2):55-63. PubMed PMID: 23008574; PubMed Central PMCID:PMC3437094.

87. Abahussain NA, Musaiger AO, Nicholls PJ, Stevens R. Nutritional status of adolescent girls in the eastern province of Saudi Arabia. Nutr Health. 1999;13(3):171-7. PubMed PMID: 10561866.

88. El-Hazmi MA, Warsy AS. A comparative study of prevalence of overweight and obesity in children in different provinces of Saudi Arabia. J Trop Pediatr. 2002;48(3):172-7. doi: 10.1093/tropej/48.3.172. PubMed PMID: 12164602.

89. Abalkhail BA, Shawky S, Soliman NK. Validity of self-reported weight and height among Saudi school children and adolescents. Saudi Med J. 2002;23(7):831-7. PubMed PMID: 12174236.

90. Al-Rukban MO. Obesity among Saudi male adolescents in Riyadh, Saudi Arabia.Saudi Med J. 2003;24(1):27-33. PubMed PMID: 12590269.

91. Al-Almaie SM. Prevalence of obesity and overweight among Saudi adolescents in Eastern Saudi Arabia. Saudi Med J. 2005;26(4):607-11. PubMed PMID: 15900370.

92. Farghaly NF, Ghazali BM, Al-Wabel HM, Sadek AA, Abbag FI. Life style and nutrition and their impact on health of Saudi school students in Abha, Southwestern region of Saudi Arabia. Saudi Med J. 2007;28(3):415-21. PubMed PMID: 17334472.

93. Farahat FM, Joshi KP, Al-Mazrou FF. Assessment of nutritional status and lifestyle pattern among Saudi Arabian school children. Saudi Med J. 2007;28(8):1298- 300. PubMed PMID: 17676227.

94. Al-Hazzaa HM. Prevalence and trends in obesity among school boys in Central Saudi Arabia between 1988 and 2005. Saudi Med J. 2007;28(10):1569-74. PubMed PMID: 17914521.

95. Al-Saeed WY, Al-Dawood KM, Bukhari IA, Bahnassy A. Prevalence and socioeconomic risk factors of obesity among urban female students in Al-Khobar city, Eastern Saudi Arabia, 2003. Obes Rev. 2007;8(2):93-9. PubMed PMID:17300275.

96. Amin TT, Al-Sultan AI, Ali A. Overweight and obesity and their relation to dietary habits and socio-demographic characteristics among male primary school children in Al-Hassa, Kingdom of Saudi Arabia. Eur J Nutr. 2008;47(6):310-8. doi: 10.1007/s00394-008-0727-6. Epub 2008 Aug 1. PubMed PMID: 18677544.

97. Mahfouz AA, Abdelmoneim I, Khan MY, Daffalla AA, Diab MM, Al-Gelban KS, Moussa H. Obesity and related behaviors among adolescent school boys in Abha City, Southwestern Saudi Arabia. J Trop Pediatr. 2008;54(2):120-4. Epub 2007 Nov 25. PubMed PMID: 18039676.

98. Khalid Mel-H. Is high-altitude environment a risk factor for childhood overweight and obesity in Saudi Arabia? Wilderness Environ Med. 2008;19(3):157-63. doi: 10.1580/07-WEME-OR-095.1. PubMed PMID: 18715124.

99. Taha AZ. Self-reported knowledge and pattern of physical activity among school students in Al Khobar, Saudi Arabia. East Mediterr Health J. 2008;14(2):344-55. PubMed PMID: 18561726.

100. Abou-Zeid AH, Hifnawy TM, Abdel Fattah M. Health habits and behaviour of adolescent schoolchildren, Taif, Saudi Arabia. East Mediterr Health J. 2009;15(6):1525- 34. PubMed PMID: 20218146.

101. Bawazeer NM, Al-Daghri NM, Valsamakis G, Al-Rubeaan KA, Sabico SL, Huang TT, Mastorakos GP, Kumar S. Sleep duration and quality associated with obesity among Arab children. Obesity (Silver Spring). 2009;17(12):2251-3. doi: 10.1038/oby.2009.169. Epub 2009 Jun 4. PubMed PMID: 19498352.

102. Al-Dossary SS, Sarkis PE, Hassan A, Ezz El Regal M, Fouda AE. Obesity in Saudi children: a dangerous reality. East Mediterr Health J. 2010;16(9):1003-8. PubMed PMID: 21218729.

103. El Mouzan MI, Foster PJ, Al Herbish AS, Al Salloum AA, Al Omer AA, Qurachi MM, Kecojevic T. Prevalence of overweight and obesity in Saudi children and adolescents. Ann Saudi Med. 2010;30(3):203-8. doi: 10.4103/0256-4947.62833. Erratum in: Ann Saudi Med. 2010 Nov-Dec;30(6):500-2. PubMed PMID: 20427936; PubMed Central PMCID: PMC2886870.

104. Washi SA, Ageib MB. Poor diet quality and food habits are related to impaired nutritional status in 13- to 18-year-old adolescents in Jeddah. Nutr Res. 2010;30(8):527- 34. doi: 10.1016/j.nutres.2010.07.002. PubMed PMID: 20851306.

105. Collison KS, Zaidi MZ, Subhani SN, Al-Rubeaan K, Shoukri M, Al-Mohanna FA. Sugar-sweetened carbonated beverage consumption correlates with BMI, waist circumference, and poor dietary choices in school children. BMC Public Health. 2010;10:234. doi: 10.1186/1471-2458-10-234. PubMed PMID: 20459689; PubMed Central PMCID: PMC2877673.

106. Abahussain NA. Was there a change in the body mass index of Saudi adolescent girls in Al-Khobar between 1997 and 2007? J Family Community Med. 2011;18(2):49-53. doi: 10.4103/2230-8229.83367. PubMed PMID: 21897910; PubMed Central PMCID: PMC3159227.

107. Alkoly, T., Abdallah, A.M., & Arabia, S. Nutritional Status and Eating Behaviors among Adolescents of Some Intermediate Schools in Jeddah. JKAU-Med. Sci. 2011;18(2)1-18. dio: 10.4197/Med. 18-2.X

108. Mahfouz AA, Shatoor AS, Khan MY, Daffalla AA, Mostafa OA, Hassanein MA.Nutrition, physical activity, and gender risks for adolescent obesity in Southwestern Saudi Arabia. Saudi J Gastroenterol. 2011;17(5):318-22. doi:10.4103/1319-3767.84486. PubMed PMID: 21912058; PubMed Central PMCID: PMC3178919.

109. Shatoor AS, Mahfouz AA, Khan MY, Daffalla AA, Mostafa O, Hammad RK. Cardiovascular risk factors among adolescent secondary school boys in Ahad Rufeida, southwestern Saudi Arabia. J Trop Pediatr. 2011;57(5):382-4. doi: 10.1093/tropej/fmq108. Epub 2010 Nov 25. PubMed PMID: 21112868

110. Al-Hazzaa HM, Abahussain NA, Al-Sobayel HI, Qahwaji DM, Musaiger AO. Lifestyle factors associated with overweight and obesity among Saudi adolescents. BMC Public Health. 2012;12:354. doi: 10.1186/1471-2458-12-354. PubMed PMID:22591544; PubMed Central PMCID: PMC3433359.

111. Al-Hazzaa HM, Musaiger AO, Abahussain NA, Al-Sobayel HI, Qahwaji DM. Prevalence of short sleep duration and its association with obesity among adolescents 15- to 19-year olds: A cross-sectional study from three major cities in Saudi Arabia. Ann Thorac Med. 2012;7(3):133-9. doi: 10.4103/1817-1737.98845. PubMed PMID: 22924070; PubMed Central PMCID: PMC3425044.

112. Al-Musharaf S, Al-Othman A, Al-Daghri NM, Krishnaswamy S, Yusuf DS, Alkharfy KM, Al-Saleh Y, Al-Attas OS, Alokail MS, Moharram O, Yakout S, Sabico S, Chrousos GP. Vitamin D deficiency and calcium intake in reference to increased body mass index in children and adolescents. Eur J Pediatr. 2012;171(7):1081-6. doi:10.1007/s00431- 012-1686-8. Epub 2012 Feb 7. PubMed PMID: 22311168.

113. Al-Nakeeb Y, Lyons M, Collins P, Al-Nuaim A, Al-Hazzaa H, Duncan MJ, Nevill A. Obesity, physical activity and sedentary behavior amongst British and Saudi youth: a cross-cultural study. Int J Environ Res Public Health. 2012;9(4):1490-506. doi: 10.3390/ijerph9041490. Epub 2012 Apr 16. PubMed PMID: 22690207; PubMed Central PMCID: PMC3366625.

114. Mahfouz AA, Shatoor AS, Hassanein MA, Mohamed A, Farheen A. Gender differences in cardiovascular risk factors among adolescents in Aseer Region, southwestern Saudi Arabia. J Saudi Heart Assoc. 2012;24(2):61-7. doi: 10.1016/j.jsha.2011.09.002. Ep

115. Al-Nuaim AA, Al-Nakeeb Y, Lyons M, Al-Hazzaa HM, Nevill A, Collins P, Duncan MJ. The Prevalence of Physical Activity and Sedentary Behaviours Relative to Obesity among Adolescents from Al-Ahsa, Saudi Arabia: Rural versus Urban Variations. J Nutr Metab. 2012;2012:417589. doi: 10.1155/2012/417589. Epub 2012 Jan 23. PubMed PMID: 22315673; PubMed Central PMCID: PMC3270420.

116. Al Buhairan F, Tamim H, Tamimi W, Al Shahri S, Al Alwan I, Magzoub M, Ahmed N, Al Dubayee M. Dietary Patterns and Weight Status of Saudi Arabian Adolescents. J Ado Health. 2012;50:(Supplement) S59-S60. doi: 10.1016/j..2011.10.160.

117. El Mouzan MI, Al Herbish AS, Al Salloum AA, Al Omar AA, Qurachi MM. Regional variation in prevalence of overweight and obesity in Saudi children and adolescents. Saudi J Gastroenterol. 2012;18(2):129-32. doi: 10.4103/1319-3767.93818. PubMed PMID: 22421719; PubMed Central PMCID: PMC3326974.

118. Al Alwan İ, Al Fattani A, Longford N. The effect of parental socioeconomic class on children's body mass indices. J Clin Res Pediatr Endocrinol. 2013;5(2):110-5. doi: 10.4274/Jcrpe.898. PubMed PMID: 23748064; PubMed Central PMCID: PMC3701916.

119. Al-Ghamdi SH. The association between watching television and obesity in children of school-age in Saudi Arabia. J Family Community Med. 2013;20(2):83-9. doi: 10.4103/2230-8229.114767. PubMed PMID: 23983559; PubMed Central PMCID: PMC3748652.

120. Al-Hazzaa HM, Al-Nakeeb Y, Duncan MJ, Al-Sobayel HI, Abahussain NA, Musaiger AO, Lyons M, Collins P, Nevill A. A cross-cultural comparison of health behaviors between Saudi and British adolescents living in urban areas: gender by country analyses. Int J Environ Res Public Health. 2013;10(12):6701-20. doi:10.3390/ijerph10126701. PubMed PMID: 24300072; PubMed Central PMCID: PMC3881136.

121. Al-Qahtani A., Al-Ghamdi, R, Al-Ghamdi K. Childhood obesity: Prevalence, risk factors and life style behaviour among primary school male childern in Al-Madinah-Al- Munawarah, Saudi Arabia. Int J Med Sci Public Health. 2013;2(4):10581-1062. doi:10.5455/ijmsph.2013.010920131.

122. Al-Hazzaa HM. Joint associations of body mass index and waist-to-height ratio with sleep duration among Saudi adolescents. Ann Hum Biol. 2014;41(2):111-7. doi: 10.3109/03014460.2013.833291. Epub 2013 Oct 7. PubMed PMID: 24098958.

123. Al-Sobayel H, Al-Hazzaa HM, Abahussain NA, Qahwaji DM, Musaiger AO. Genderdifferences in leisure-time versus non-leisure-time physical activity among Saudi adolescents. Ann Agric Environ Med. 2015;22(2):344-8. doi: 10.5604/12321966.1152091. PubMed PMID: 26094536.

124. Alenazi SA, Koura HM, Zaki SM, Mohamed AH. Prevalence of Obesity Among Male Adolescents in Arar Saudi Arabia: Future Risk of Cardiovascular Disease. Indian J Community Med. 2015;40(3):182-7. doi: 10.4103/0970-0218.158864. PubMed PMID: 26170543; PubMed Central PMCID: PMC4478660.

125. Al-Mutairi RL, Bawazir AA, Ahmed AE, Jradi H. Health Beliefs Related to Diabetes Mellitus Prevention among Adolescents in Saudi Arabia. Sultan Qaboos Univ Med J. 2015;15(3):e398-404. doi: 10.18295/squmj.2015.15.03.015. Epub 2015 Aug 24. PubMed PMID: 26355752; PubMed Central PMCID: PMC4554276.

126. El-Kholy T, Elsayed E. Association of physical activity and health status with intelligence quotient of high school students in Jeddah. J Phys Ther Sci. 2015;27(7):2039-43. doi: 10.1589/jpts.27.2039. Epub 2015 Jul 22. PubMed PMID:26311922; PubMed Central PMCID: PMC4540813.

127. Musaiger AO, Al-Mannai M, Al-Haifi AR, Nabag F, Elati J, Abahussain N, Tayyem R, Jalambo M, Benhamad M, Al-Mufty B. Prevalence of overweight and obesity among adolescents in eight Arab countries: comparison between two international standards (ARABEAT-2). Nutr Hosp. 2016;33(5):567. doi: 10.20960/nh.567. PubMed PMID: 27759971.

128. Alshammari E, Suneetha E, Adnan M, Khan S, Alazzeh A. Growth Profile and Its Association with Nutrient Intake and Dietary Patterns among Children and Adolescents in Hail Region of Saudi Arabia. Biomed Res Int. 2017;2017:5740851. doi:

10.1155/2017/5740851. Epub 2017 Feb 20. PubMed PMID: 28316981; PubMed Central PMCID: PMC5337866.

129. Bajamal E, Robbins LB, Ling J, Smith B, Pfeiffer KA, Sharma D. Physical Activity Among Female Adolescents in Jeddah, Saudi Arabia: A Health Promotion Model-Based Path Analysis. Nurs Res. 2017;66(6):473-482. doi:10.1097/NNR.0000000000000244. PubMed PMID: 29095378.

130. Al Dahi SK, Rofayda MA, Eman GY, Rami MA, Sanna HE, Malak ME, Fatma AA. Adolescents’ overweight and obesity among Alabnaa schools in Tabuk, Saudi Arabia. Saudi J Obesity [serial online] 2017 [cited 2019;5:3-7. Available from: http://www.saudijobesity.com/text.asp?2017/5/1/3/210584.

131. Farsi DJ, Elkhodary HM. The prevalence of overweight/obesity in high school adolescents in Jeddah and the association of obesity association with dental caries. Ann Saudi Med. 2017;37(2):114-121. doi: 10.5144/0256-4947.2017.114. PubMed PMID: 28377540; PubMed Central PMCID: PMC6150552.

132. Adahli MA, Mohamed AG, Alkhashan H. Association of overweight and obesity with decline in academic performance among female high-school students, Riyadh, Saudi Arabia. East Mediterr Health J. 2017;22(12):887-893. PubMed PMID: 28181664.

133. Alazzeh AY, AlShammari EM, Smadi MM, Azzeh FS, AlShammari BT, Epuru S, Banu S, Bano R, Sulaiman S, Alcantara JC, Ashraf SA, Qiblawi S. Some Socioeconomic Factors and Lifestyle Habits Influencing the Prevalence of Obesity among Adolescent Male Students in the Hail Region of Saudi Arabia. Children (Basel). 2018;5(3). pii: E39. doi: 10.3390/children5030039. PubMed PMID: 29522445; PubMed Central PMCID: PMC5867498.

134. Al-Kadi A, Malik AM, Mansour AE. Rising incidence of obesity in Saudi residents. A threatening challenge for the surgeons. Int J Health Sci (Qassim). 2018;12(1):45-49. PubMed PMID: 29623017; PubMed Central PMCID: PMC5870314.

135. Demography Survey. General Authority for Statistics, Kingdom of Saudi Arabia. Available from: https://www.stats.gov.sa/sites/default/files/en-demographic-research- 2016_2.pdf

136. Mohammed M, Eggers SM, Alotaiby FF, de Vries N, de Vries H. Smoking uptake among Saudi adolescents: tobacco epidemic indicators and preventive actions needed. Glob Health Promot. 2018;25:6-15. doi: 10.1177/1757975914548193

137. Farrag NS, Cheskin LJ, Farag MK. A systematic review of childhood obesity in the Middle East and North Africa (MENA) region: Prevalence and risk factors meta- analysis. Adv Pediatr Res 2017;4. doi: 10.12715/apr. 2017.4.8.

138. Obesity: Preventing and managing the global epidemic. Report of a WHO consultation. World Health Organ Tech Rep Ser;2000. p. 100- 42.

139. Lobstein T, Baur L, Uauy R. IASO International. Obesity in children and young people: A crisis in public health. Obesity Rev 2004;5:4- 85.

140. Al- Dossary SS, Sarkis PE, Hassan A, Ezz El Regal M, Fouda AE. Obesity in Saudi children: A dangerous reality. East Mediterr Health J 2010;16:1003- 8.

141. Al- Othaimeen AI, Al- Nozha M, Osman AK. Obesity: An emerging problem in Saudi Arabia. Analysis of data from National Nutritional Survey. East Mediterr Health J 2007;13:441- 447.

142. El Hazmi MA, Warsy AS. Prevalence of obesity in the Saudi population. Ann Saudi Med 1997;17:302- 306.

143. World Health Organization: Nutrition. Healthy diet, Fact sheet No. 394. Updated August 2018 https://www.who.int/nutrition/publications/nutrientrequirements /healthydiet_factsheet/en/, accessed on Aug. 9, 2019.

144. World Health Organization: Physical activity. https://www.who.int/news-room/factsheets/detail/physical-activity, on Aug. 7, 2019.

145. Anderson PM, Butcher KE. Childhood obesity: Trends and potential causes. Future Child. 2006;16:19–45.

146. Story M, Neumark-stainzer D, French S. Individual and environmental influences on adolescent eating behaviours. J Am Diet Assoc. 2002;102:S40–51.

147. Olds T, Maher C, Zumin S, Péneau S, Lioret S, Castetbon K, et al. Evidence that the prevalence of childhood overweight is plateauing: Data from nine countries. Int J Pediatr Obes 2011;6:342-60.

148. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adult obesity in the United States, 2011–2012. JAMA 2014;311:806-14.

149. Blüher S, Meigen C, Gausche R, Keller E, Pfäffle R, Sabin M, et al. Age-specific stabilization in obesity prevalence in German children: A cross-sectional study from 1999 to 2008. Int J Pediatr Obes 2011;6:e199-206.

150. Butland B, Jebb S, Kopelman P, McPherson K, Thomas S, Mardell J, Parry V. Foresight. Tackling obesities: future choices – project report (2nd Edition). London, UK: Government Office for Science; 2007. www.gov.uk/government/uploads/system/ uploads/attachment_data/file/287937/07-1184x-tackling-obesities-future-choices- report.pdf, accessed on Aug.8, 2019.

151. World Health Organization. Consideration of the evidence on childhood obesity for the Commission on Ending Childhood Obesity: report of the adhoc working group on science and evidence for ending childhood obesity. Geneva: WHO; 2016. apps.who.int/iris/ bitstream/10665/206549/1/9789241565332 _eng.pdf, accessed on 14 Aug. 2019.

152. Milaat W. Public Health in the Saudi Health System: A Search for New Guardian. Saudi J Med Med Sci. 2014;2:77-80.

153. World Health Organization: Global Reproductive, Maternal, Newborn, Child and Adolescent Health Policy Survey. Saudi Arabia. https://www.who.int/6d64466d-3096- 4050-af19-e33be8caf4be, accessed on Aug. 10, 2019.

154. Aldubayan K, Murimi M. Compliance with school nutrition policy in Saudi Arabia: a quantitative study. East Mediterr Health J. 2019 Jun 4;25(4):230-238. doi: 10.26719/emhj.18.034.

Appendices 1 ü School/ food environment 2 ü ü Mobility/ urbanization 3 ü ü ü sleep Stress/ patterns smoking/ 7 ü ü ü ü ü ü ü activity Physical 0 Label general literacy/ education 6 ü ü ü ü ü ü Diet contents patterns/ 6 ü ü ü ü ü ü time Social screen media &

Determinants of Overweight and Obesity 7 ü ü ü ü ü ü ü factors Household Economics/ 4 ü ü ü ü Parents’ employment 9 ü ü ü ü ü ü ü ü ü Parents' education =World Health Organization 4 ü ü ü ü Hx of obesity & Family Family size WHO NA NA NA NA NA CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC CDC IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF IOTF WHO WHO WHO WHO WHO WHO WHO WHO WHO WHO WHO WHO WHO criteria OW/OB WHO+CDC WHO+IOTF =not available; NA (Arar) (Abha) (Abha) (Abha) (Abha) (Abha) (Asser) (Tabuk) (Jeddah) (Jeddah) (Jeddah) (Jeddah) (Albahah) (Jeddah) (Jeddah) (Hayel) (Jeddah) (Hayel) (Riyadh) (Riyadh) (Riyadh) (Riyadh) (AlHassa) (Madinah) (Madinah) (Qassim) (Alhassa) (Alhassa) (Riyadh) (Riyadh) (Riyadh) (Riyadh) (Taif/Hada) (Alkhobar) (Alkhobar) (Alkhobar) (Alkhobar) (Alkhobar) (Dammam) E/C/W E/C/W E/C/W E/C/W E/C/W E/N/W Region National National Eeastern Eeastern C/S/W/N C/E/S/W/N Central Central Northern Central Central Central Central Central Central Central Central Southern Southern Southern Southern Southern Central Southern Eastern Eastern Northern Western Western Western Western Western Western Western Eastern Eeastern Eastern Eastern Eastern Eastern Eastern Western Western Southern Western CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CC CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS CS Study Design Journal National National National National National National National National National National National National National National National National National =International Obesity Task Force; Publication International International International International International International International International International International International International International International International International International International International International International International International International International International International International International International International International International International Summary of Reviewed Articles & Social Determinants of Overweight and Obesity. IOTF Age 9-18 9-14 13-18 14-18 10-19 12-19 16-16 12-20 14-19 12-18 12-19 10-14 10-17 10-14 11-19 10-15 13-18 12-19 10-19 10-15 13-18 10-19 15-19 10-19 11-19 15-19 14-19 15-19 13-17 15-17 12-19 15-19 10-18 13-18 10-16 11-14 14-18 15-19 14-19 14-17 15-19 15-25 16-19 15-18 13-18 13-18 11-19 15-19 15-17 12-19 15-19 (years) # 70 65 74 676 440 797 175 143 127 321 620 103 538 620 607 701 196 851 205 450 720 405 980 415 257 = Case Control; 3210 3698 1172 1457 1091 1610 1009 1331 2633 1319 4400 1506 1389 1014 1541 1474 1507 1500 Study Characteristics 43417 Female CS Appendix 1. # 70 82 70 34 885 675 327 657 175 875 141 112 600 663 705 542 201 767 197 523 221 518 700 852 386 3142 3853 3223 2870 1403 1139 2696 1240 3244 1659 5033 1249 1249 1400 1379 1249 1581 1378 1401 1388 1495 Male 54249 # = Case Control; 676 885 767 350 284 239 321 140 185 397 197 523 426 135 968 405 801 257 108 6352 7551 3223 4042 2860 1766 1454 1610 1139 2696 1884 2571 5877 2978 9433 1869 1249 2906 2768 1138 1869 1270 1719 3122 1243 1618 2852 2908 2888 1420 1832 1495 Total 97666 CC 2002 2010 1996 1997 1999 2002 2003 2005 2007 2007 2007 2006 2008 2008 2008 2008 2009 2009 2010 2010 2010 2011 2011 2011 2011 2012 2012 2012 2012 2012 2012 2012 2012 2013 2013 2013 2013 2013 2014 2015 2015 2015 2015 2016 2017 2017 2017 2017 2017 2018 2018 Year Author El-Hazmi, et al. El Mouzan, , et al. Al-Nuaim, et al. Ghabrah, et al. Abahussain, et al. Abalkhail, et al. Al-Rukban, et al. Al-Almaie,et al. Farghaly, et al. Farahat, , et al. Al-Hazzaa, H. Al-Saeed, et al. Amin, et al. Mahfouz, et al. Khalid, et al. Taha, A. Abou-Zeid, et al. Bawazeer, et al. Dossary, , et al. Washi, , et al. Collison, , et al. Abahussain, N. AbdAllah, , et al. Mahfouz, , et al. Shatoor, , et al. Al-Hazzaa, , et al. Al-Hazzaa, , et al. Al-Musharaf, et al. Al-Nakeeb, , et al. Mahfouz, , et al. Al-Nuaim, , et al. AlBuhairan, et al. El Mouzan, , et al. Al Alwan,, et al. Al-Ghamdi, S. Al-Hazzaa, , et al. Ghamdi, , et al. Al-Hazzaa, H. Al-Hazzaa, , et al. Al-Sobayel, , et al. Alenazi, , et al. Al-Mutairi, et al. El-Kholy, T. Musaiger, et al. Al Shammari, et al. Bajamal, et al. Al Dahi, et al. Farsi, et al. Adaili, et al. Alazzeh et al. Al-Kadi, et al. =Centers for Disease Control; # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 CDC

78 29 Total 13.9 38.4 25.5 28.4 39.3 27.8 28.1 16.6 27.1 26.4 44.8 23.4 41.7 13.1 27.1 27.3 34.8 36.6 29.4 36.5 37.6 34.1 34.8 24.4 26.2 24.4 25.3 29.5 (Female) OW+OB% 29 16.9 23.4 13.1 34.8 36.6 29.4 24.4 Reported (Female) OW+OB% 13.9 38.4 25.5 28.4 39.3 27.8 28.1 27.1 26.4 44.8 41.7 27.1 27.3 36.5 37.6 34.1 34.8 24.4 26.2 25.3 29.5 (Female) Calculated OW+OB% 10 13 14 7.5 9.5 5.6 5.7 7.8 OB% 26.4 11.2 15.4 12.4 10.6 18.4 20.2 13.8 17.1 17.7 10.6 12.9 18.1 10.7 10.9 16.9 Reported (Female) 27 6.4 28.4 12.5 17.2 23.9 18.3 15.7 16.5 20.8 26.4 21.5 21.4 13.5 19.5 18.8 21.9 20.8 13.7 15.3 17.5 12.6 OW % Reported (Female) 35 43 8.7 Total 33.4 31.8 28.3 34.3 29.5 23.9 22.8 28.2 21.4 35.4 24.8 31.2 44.4 21.4 33.7 16.1 27.2 23.3 23.3 43.6 36.8 20.6 35.2 33.5 41.9 40.1 43.6 47.6 47.5 21.7 22.4 48.3 (Male) OW+OB% 8.7 23.9 35.9 21.4 16.1 43.6 20.6 21.7 (Male) Reported OW+OB% 35 43 33.4 31.8 28.3 34.3 29.5 22.8 28.2 21.4 24.8 31.2 44.4 33.7 27.2 23.3 23.3 36.8 35.2 33.5 41.9 40.1 43.6 47.6 47.5 22.4 48.3 (Male) Calculated OW+OB% 14 18 27 9.9 OB% 17.4 11.2 20.5 33.3 20.5 19.3 16.3 18.1 12.2 21.6 12.9 11.8 11.8 19.9 19.1 11.2 22.6 24.9 24.1 20.8 17.2 23.7 24.3 12.5 11.54 (Male) Reported Prevalence of Overweight and Obesity 16 6.5 9.2 9.9 24.8 11.3 14.3 13.8 10.2 10.1 13.3 21.3 26.4 12.1 14.2 11.5 11.5 16.9 16.1 22.3 19.3 15.2 19.5 30.4 19.3 23.2 21.3 OW % (Male) Reported 28 16 25 33 38 21 40 Total 22.7 28.7 34.9 21.2 33.2 47.6 44.7 36.6 27.2 52.6 38.9 39.5 37.8 32.7 34.9 26.3 18.1 47.2 (M+F) OW+OB% 28 25 33 21 22.7 44.7 38.9 39.5 18.1 (M+F) Reported OW+OB% 16 38 40 28.7 34.9 21.2 33.2 47.6 36.6 27.2 52.6 37.8 32.7 34.9 26.3 47.2 (M+F) Calculated OW+OB% (M+F) 5 24 9.7 9.3 15.6 16.8 14.5 27.5 21.1 29.4 13.5 16.4 22.3 18.5 14.9 28.7 Reported OB% 11 16 13.1 18.1 11.5 18.7 20.1 15.5 17.9 23.2 24.3 16.3 12.6 19.5 11.4 18.5 (M+F) OW % Reported N W Summary of Reviewed Regional & Prevalence Rates of Overweight and Obesity. (Arar) (Abha) (Abha) (Abha) (Abha) (Abha) (Asser) (Hail) (Tabuk) (Hail) (Jeddah) (Jeddah) (Jeddah) (Albahah) (Jeddah) (Jeddah) (Jeddah) (Jeddah) (Riyadh) (Riyadh) (Riyadh) (Riyadh) (Madinah) (Qassim) (Alhassa) (AlHassa) (Riyadh) (Riyadh) (Riyadh) (Riyadh) (Taif/Hada) (AlHassa) (Dammam) (Alkhobar) (Alkhobar) (Alkhobar) (Alkhobar) (Alkhobar) E/N/W E E/C/W E/C/W E/C/W E/C/W E/C/W Region National National Eeastern Eeastern C/S/W/N C/E/S/W/N Central Central Northern Central Central Central Central Central Central Central Central Southern Southern Southern Southern Southern Central Southern Eastern Eastern Eastern Northern Western Western Western Western Western Western Western Eastern Eastern Eastern Eastern Eastern Eastern Western Southern Western Appendix 2. # 70 65 74 676 440 797 175 143 127 321 620 103 538 620 607 701 851 205 450 720 405 980 415 257 3210 3698 1172 1457 1091 1610 1009 1331 2633 1319 4400 1506 1389 1014 1541 1474 1507 1500 43221 Female # 70 82 70 34 885 675 327 657 175 875 141 112 600 663 705 542 767 197 523 221 518 700 852 386 3142 3853 3223 2870 1403 1139 2696 1240 3244 1659 5033 1249 1249 1400 1379 1249 1581 1378 1401 1388 1495 54048 Male # 676 885 767 350 284 239 321 140 185 197 523 426 135 968 405 801 257 108 6352 7551 3223 4042 2860 1766 1454 1610 1139 2696 1884 2571 5877 2978 9433 1869 1249 2906 2768 1138 1869 1270 1719 3122 1243 1618 2852 2908 2888 1420 1832 1495 97269 Total Study Characteristics 2002 2010 1996 1997 1999 2002 2003 2005 2007 2007 2007 2006 2008 2008 2008 2008 2009 2009 2010 2010 2010 2011 2011 2011 2011 2012 2012 2012 2012 2012 2012 2012 2012 2013 2013 2013 2013 2014 2015 2015 2015 2015 2016 2017 2017 2017 2017 2017 2018 2018 Year Author El-Hazmi, et al. El Mouzan, , et al. Al-Nuaim, et al. Ghabrah, et al. Abahussain, et al. Abalkhail, et al. Al-Rukban, et al. Al-Almaie,et al. Farghaly, et al. Farahat, , et al. Al-Hazzaa, H. Al-Saeed, et al. Amin, et al. Mahfouz, et al. Khalid, M. Taha, A. Abou-Zeid, et al. Bawazeer, et al. Dossary, , et al. Washi, , et al. Collison, , et al. Abahussain, N. AbdAllah, , et al. Mahfouz, , et al. Shatoor, , et al. Al-Hazzaa, , et al. Al-Hazzaa, , et al. Al-Musharaf, et al. Al-Nakeeb, , et al. Mahfouz, , et al. Al-Nuaim, , et al. AlBuhairan, et al. El Mouzan, , et al. Al Alwan,, et al. Al-Hazzaa, , et al. Ghamdi, , et al. Al-Hazzaa, H. Al-Hazzaa, , et al. Al-Sobayel, , et al. Alenazi, , et al. Al-Mutairi, et al. El-Kholy, T. Musaiger, et al. Al Shammari, et al. Bajamal, et al. Al Dahi, et al. Farsi, et al. Adaili, et al. Alazzeh et al. Al-Kadi, et al. # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 22 23 24 25 26 27 28 29 30 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

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