Eating disorders, such as anorexia nervosa, bulimia, and binge eating, are characterized by an unusual attitude towards food that may cause an individual to alter their eating habits and eating behaviors.
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No single cause for eating disorders has been established. Although a preoccupation with body weight and body shape appears to be central to all eating disorders, research has so far shown that eating disorders are associated with, but not caused by, many different factors, which may be genetic, cultural, social, behavioral, psychological, or biological.
Therefore, any “cause” of an eating disorder may be multifactorial and complex.
Risk factors
Eating disorders can affect individuals of any race, age, or socioeconomic class. Risk factors that increase the likelihood of developing an eating disorder include genetic factors, influences at home or at school, the individual's personality, the presence of certain psychological conditions, cultural pressures, or a number of biological factors.
Genetic factors
Research suggests that genetic factors may increase the likelihood of an individual developing an eating disorder. Individuals with a first-degree relative who has a history of an eating disorder are more likely than individuals without such a relative to develop an eating disorder.
In addition, researchers have identified specific genes that influence hormones such as leptin and ghrelin. Experts believe that, as well as regulating feeding, these hormones may influence the personality traits and behaviors that are associated with anorexia and bulimia.
External influences
Existing research into the role of the family in triggering an eating disorder is largely cross-sectional, retrospective, and unsubstantiated. However, it has been suggested that parents’ behaviors may influence their child’s eating habits. For example, mothers who diet or worry excessively about their weight may trigger their child to develop an abnormal attitude towards food, as may a father or sibling who teases an individual about their weight or shape.
Similarly, comments made by classmates in the school environment can influence a child’s attitude towards eating. Additionally, a parent or teacher’s high expectations of a child’s performance at school may also help lay the foundations for an eating disorder.
Personality
People with eating disorders tend to share similar personality and behavioral traits such as low self-esteem, perfectionism, approval-seeking, dependency, and problems with self-direction.
In addition, specific personality disorders can increase the risk for developing eating disorders, some of which include avoidant personality disorder, obsessive-compulsive personality disorder, borderline personality disorder, and narcissistic personality disorder.
- Avoidant personality disorder: People with this condition are typically perfectionists, emotionally and sexually inhibited, non-rebellious, and terrified of being criticized or humiliated.
- Obsessive-compulsive personality disorder: Individuals with this disorder may be perfectionists, morally rigid, or overly concerned with rules and order.
- Borderline personality disorder: This disorder is associated with self-destructive and impulsive behaviors.
- Narcissistic personality disorder: Features of this disorder include an inability to comfort oneself or to empathize with others, as well as a need for admiration and oversensitivity to criticism or defeat.
Psychological factors
Psychological conditions such as post-traumatic stress disorder (PTSD), panic disorder, phobias, and depression have all been associated with abnormal eating habits, as have life stressors such as job loss, divorce, or coping with bullying or learning difficulty such as dyslexia.
Stressful or upsetting situations such as tight deadlines at work, school, or university, as well as experiencing the death of a loved one, are all examples of factors that may contribute to the development of an eating disorder.
Why Do People Develop Eating Disorders?
Body image disorders
Body image disorders such as body dysmorphic disorder, where an individual has a distorted view of their body, or muscle dysmorphia, which describes an obsession with muscle mass, are often associated with anorexia or bulimia.
Cultural pressures
The impact of the media in Western culture can fuel a desire for, or obsession with the idea of, becoming thin. In the media, thinness or slimness is often equated with success and popularity, which may cultivate and encourage the idea of being thin, especially among young girls.
However, the media also fiercely markets cheap and calorific foods, which can cause confusion and stress. Pressure to become thin may also be perceived by individuals who take part in competitive or athletic activities such as modeling, ballet, or running. As a result, people can develop unrealistic expectations for their body image and place an overemphasis on the importance of being thin.
Biologic factors
A bodily system called the hypothalamic-pituitary-adrenal axis (HPA) may play an important role in eating disorders. The HPA releases regulators of appetite, stress, and mood such as serotonin, norepinephrine, and dopamine. Abnormalities of these chemical messengers are considered to play an important role in eating disorders.
Serotonin is important in the control of anxiety and appetite, whereas norepinephrine is a stress regulator and dopamine plays a role in reward-seeking behavior. An imbalance of serotonin and dopamine may help to explain why people with anorexia do not derive a sense of pleasure from food and other common comforts.
References
Further Reading
Calorie information on menus: Worsening eating disorders?