AN INVESTIGATION INTO THE GENETIC AND ENVIRONMENTAL FACTORS CONTRIBUTING TO THE ONSET OF EATING DISORDER IN ADOLESCENTS

CHAPTER ONE

INTRODUCTION

1. Background of the study

Eating disorders (EDs) are serious mental health illnesses marked by enduring disruptions in eating habits and body image beliefs, which considerably hinder physical health and psychosocial functioning (American Psychiatric Association [APA], 2013). These disorders, such as anorexia nervosa, bulimia nervosa, and binge-eating disorder, often emerge during adolescence, a phase characterised by significant biological, psychological, and social transformations (Stice et al., 2015). Adolescence is a period characterised by heightened worries around body image and peer influence, which significantly increases susceptibility to the development of disordered eating behaviours (Rodgers et al., 2020). The incidence of eating problems among teenagers has been consistently increasing. Recent research reveal that over 2.7% of teenagers globally suffer from a clinical eating problem annually, with a considerable number exhibiting subclinical symptoms that substantially impact their quality of life (Qian et al., 2023). In the United States, as many as 10% of teenagers may fulfil the criteria for an eating disorder prior to reaching adulthood, underscoring the considerable public health challenge posed by these diseases (Lipson & Sonneville, 2017). The rising incidence requires a thorough understanding of the variables leading to the emergence of eating disorders, especially in adolescents.

Genetic factors significantly predispose people to eating disorders, as shown by twin and family studies indicating a heritability estimate of 50-83% for these diseases (Culbert, Racine, & Klump, 2015). A familial history of eating disorders, mood disorders, or anxiety disorders elevates the likelihood of developing disordered eating behaviours (Trace et al., 2016). Certain genetic variants, particularly those impacting serotonin and dopamine pathways, have been linked to increased vulnerability to eating disorders, altering appetite management, mood, and reward processing (Baker et al., 2020). However, genetic predisposition alone is inadequate to induce eating disorders; the interplay between genetic vulnerabilities and environmental stimuli is crucial.

Environmental factors significantly contribute to the development of eating disorders, including societal, family, and individual variables. Sociocultural influences, especially the widespread idealisation of thinness in Western societies, greatly contribute to body dissatisfaction and harmful weight management behaviours in teenagers (Rodgers et al., 2020). Media exposure, particularly via social media platforms, intensifies these pressures by consistently showcasing unattainable beauty standards, resulting in heightened body dissatisfaction and the internalisation of slender ideals (Grabe, Ward, & Hyde, 2018). Additionally, familial dynamics, including parental perspectives on weight and dieting, may significantly affect teenagers' body image views and eating habits (Tylka & Kroon Van Diest, 2015). The interplay between genetic and environmental elements, referred to as gene-environment interaction, is crucial for understanding the emergence of eating disorders. Adolescents with a genetic predisposition to mood dysregulation may exhibit heightened vulnerability to external stressors, such as peer judgement about weight, thereby precipitating disordered eating behaviours (Culbert et al., 2015). Moreover, early life stresses, such as childhood trauma or abuse, have been shown to elevate the likelihood of developing eating disorders, particularly in those with a genetic susceptibility to emotional dysregulation (Troop & Treasure, 2016). The emergence of eating disorders in adolescence correlates with substantial neurodevelopmental changes, including modifications in brain areas associated with reward processing, impulse regulation, and emotional management (Stice & Burger, 2019). Hormonal fluctuations throughout puberty, especially in females, may heighten susceptibility to body image disorders and dietary behaviours (Klump et al., 2015). Research indicates that hereditary variables may affect the neurological response to environmental stimuli, hence increasing the chance of developing eating disorders in some people (Bulik et al., 2017). Notwithstanding considerable progress in comprehending eating disorders, a deficiency persists in elucidating the interaction between hereditary and environmental variables that affect the risk of these problems throughout adolescence.. Therefore, the researcher sought to investigate the genetic and environmental factors contributing to the onset of eating disorder in Adolescents.

1.2 Statement of the problem

Eating disorders are intricate mental health illnesses shaped by a confluence of hereditary and environmental influences. Adolescence, a pivotal developmental stage, is notably linked to the emergence of these diseases owing to rapid physical, emotional, and social changes (Stice et al., 2015). Genetic predispositions may heighten susceptibility, but contextual factors, including familial interactions, social pressures, and cultural standards, significantly contribute to the emergence of disordered eating behaviours (Culbert, Racine, & Klump, 2015). Notwithstanding increased awareness, the incidence of eating disorders in teenagers persists in escalating, with over 2.7% of adolescents globally affected by a clinical eating disorder annually (Qian et al., 2023).
A gap persists in comprehending the interaction between certain genetic variables and environmental stresses in relation to the likelihood of developing eating disorders throughout adolescence. For example, while a familial history of mental health illnesses, especially mood disorders, is recognised as a factor in genetic predisposition, the mechanisms that explain this relationship remain ambiguous (Trace et al., 2015). Moreover, environmental influences, including exposure to social media that often reinforces unrealistic body image ideals, have been associated with heightened body dissatisfaction and eating disorders in teenagers (Rodgers et al., 2020). The degree to which these environmental influences intensify genetic vulnerability is inadequately understood. Hence, the need to investigate the genetic and environmental factors contributing to the onset of eating disorder in Adolescents.

1.3 Objective of the study

The broad objective of the study is to investigate the genetic and environmental factors contributing to the onset of eating disorder in Adolescents. The specific objectives is as follows

1. To examine the prevalence of eating disorders among adolescents.

2. To identify the common types of eating disorders among adolescents during their developmental period

3. To assess the genetic factors increasing susceptibility to eating disorders among adolescents.

4. To explore the influence of environmental factors influencing the onset of eating disorders among adolescents.

1.4 Research questions

The following questionshave been prepared to guide the study

1. What is the prevalence of eating disorders among adolescents?

2. What are the common types of eating disorders among adolescents during their developmental period?

3. What are the genetic factors increasing susceptibility to eating disorders among adolescents?

4. What is the influence of environmental factors influencing the onset of eating disorders among adolescents?

1.5 Significance of the study

Findings of the study will be significant to the ministry of health as eating disorders are associated with significant physical, psychological, and social consequences, this research can contribute to public health efforts aimed at reducing the prevalence and impact of these conditions. By identifying modifiable risk factors, the study can support initiatives to lower the incidence of eating disorders and related health complications among adolescents.

Findings of the study will also be significant to the academic community as it will contribute to existing literature, add to library resources and serve as a guide to future researchers.

1.6 Scope of the study

The study focus on the genetic and environmental factors contributing to the onset of eating disorder in Adolescents. Empirically, the study will examine the prevalence of eating disorders among adolescents, identify the common types of eating disorders among adolescents during their developmental period, assess the genetic factors increasing susceptibility to eating disorders among adolescents and explore the influence of environmental factors influencing the onset of eating disorders among adolescents.

Geographically, the study will be delimited to adolescents in junior secondary schools in Burutu LGA, Delta state.

1.7 Limitation of the study

Like in every human endeavour, the researchers encountered slight constraints while carrying out the study. The significant constraint are:

Time: The researcher encountered time constraint as the researcher had to carry out this research along side other academic activities such as attending lectures and other educational activities required of her.

Finance: The researcher incurred more financial expenses in carrying out this study such as typesetting, printing, sourcing for relevant materials, literature, or information and in the data collection process.

Availability of Materials: The researcher encountered challenges in sourcing for literature in this study. The scarcity of literature on the subject due to the nature of the discourse was a limitation to this study.

1.8 Definition of terms

Eating Disorders (EDs): A group of mental health conditions characterized by abnormal eating behaviors, body image distortions, and significant concerns about weight and shape, which impair physical health and psychosocial functioning. Common types include anorexia nervosa, bulimia nervosa, and binge-eating disorder.

Genetic Factors: Hereditary characteristics passed from parents to offspring through genes, which can influence the likelihood of developing certain conditions, including mental health disorders. In the context of eating disorders, genetic factors may involve variations in genes affecting mood, appetite regulation, and emotional processing .

Environmental Factors: External influences that affect an individual's behavior and development, such as family dynamics, cultural norms, peer influences, and media exposure. These factors can contribute to the onset of eating disorders by shaping body image perceptions and eating behaviors.

Adolescents: Individuals in the developmental stage between childhood and adulthood, typically ranging from ages 10 to 19. Adolescence is characterized by significant physical, emotional, and cognitive changes, making it a critical period for the onset of eating disorders (World Health Organization .

Gene-Environment Interaction: The combined effect of genetic predisposition and environmental exposures on the development of a condition. In the case of eating disorders, certain genetic traits may increase sensitivity to environmental risk factors, such as stress or social pressures, leading to the onset of disordered eating behaviors.

Body Dissatisfaction: Negative self-evaluation of one's body size, shape, or weight, often resulting from the internalization of societal beauty standards. It is a significant risk factor for the development of eating disorders, especially among adolescents .

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