What causes eating disorders?

While eating disorders may begin with preoccupations with food and weight, they are most often about much more than food.

Eating disorders are complex conditions that arise from a combination of long-standing behavioural, emotional, psychological, interpersonal, and social factors. Scientists and researchers are still learning about the underlying causes of these emotionally and physically damaging conditions. We do know, however, about some of the general issues that can contribute to the development of eating disorders.

People with eating disorders often use food and the control of food in an attempt to compensate for feelings and emotions that may otherwise seem overwhelming. For some, dieting, bingeing, and purging may begin as a way to cope with painful emotions and to feel in control of one’s life, but ultimately, these behaviours will damage a person’s physical and emotional health, self-esteem, and sense of competence and control.

Psychological factors that can contribute to eating disorders:

Interpersonal factors that can contribute to eating disorders:

  • troubled family and personal relationships 
  • difficulty expressing emotions and feelings 
  • history of being teased or ridiculed based on size or weight 
  • history of physical or sexual abuse

Social factors that can contribute to eating disorders:

  • cultural pressures that glorify "thinness" and place value on obtaining the "perfect body" 
  • narrow definitions of beauty that include only women and men of specific body weights and shapes 
  • cultural norms that value people on the basis of physical appearance and not inner qualities and strengths

Other factors that can contribute to eating disorders

Scientists are still researching possible biochemical or biological causes of eating disorders. In some individuals with eating disorders, certain chemicals in the brain that control hunger, appetite, and digestion have been found to be imbalanced. The exact meaning and implications of these imbalances remain under investigation.

Eating disorders are complex conditions that can arise from a variety of potential causes. Once started, however, they can create a self-perpetuating cycle of physical and emotional destruction. All eating disorders require professional help.

Why do people develop eating disorders?

The question to why people develop eating disorders is a difficult one to answer. It may be that there is no one answer or too many answers.

There are many factors that appear to trigger the development of eating disorders. There are certainly plenty of theories about the influences that are thought to be important in causing anorexia nervosa or bulimia nervosa. Some people are convinced that certain kinds of family problems or childhood traumas could be the cause, while others blame the media and fashion industries.

In very general terms, eating disorders seem to be linked with and may be triggered by unhappiness and emotional difficulties.

Some causes of eating disorders: 

1. biochemistry
2. genetics
3. personality
4. emotional
5. social and family environment
6. media images and messages about food and dieting


Eating disorders are often associated with chemical imbalances in the brain. These have been found to be similar to the chemical imbalances associated with depression and obsessive-compulsive disorder (OCD).

Low levels of some neurotransmitters, for example, serotonin and noradrenaline, are found in acutely ill anorexia and bulimia sufferers. Serotonin is associated with suppression of appetite and mood, low serotonin levels are linked to bingeing and depression.

Anorexia nervosa and depression feature high levels of cortisol, this is a hormone released by the brain in response to stress.

A hormone called CCK, found to be at low levels in people with bulimia nervosa, causes animals to feel full and stop eating.

Note: We do not know much detail about how these chemicals in the brain work, whether biochemical changes are the cause of disorders or effects of having the disorder.


Eating disorders, especially anorexia nervosa, tend to run in families. This suggests there might be a genetic factor.

Twin studies carried out in identical twins brought up together have shown a 50% concordance rate resemblance for anorexia nervosa, this suggests possible genetic factors. The link is less clear for bulimia nervosa – studies of identical twins have shown concordance rates of 23%.

Genetic factors and social, environment influences within a family are hard to separate, some studies have shown evidence that family tension may trigger eating disorders.

Anorexia and bulimia nervosa are most commonly reported in white people in western societies. How much this is due to genetic factors and how much it is due to social and cultural pressures is hard to tell.

A study in Fiji showed a sudden increase in eating disorders among young women since the arrival of television in 1995, (Fearn, 1999). This suggests a strong social and cultural component.

There may be a genetic component that makes some people more likely to develop an eating disorder in response to stress or other environmental factors.

Psychological and social explanations

Personality might play a part: sufferers of anorexia nervosa and bulimia nervosa tend to have perfectionist personalities. Sufferers desperately want to be accepted and valued and tend to feel that they are not.

The media create unrealistic, and for most people, unattainable ‘ideal’ images, especially of women. Most models are well below normal weight for their age and height. Successful women in films are almost always portrayed as thin.

Eating restraint is a part of almost all eating disorders. The most common reason for restraining eating is to try to lose weight. The reason why someone decides to start slimming in the first place is also very complex. Someone who sets out to lose weight is dissatisfied with themselves or some aspect of their body.

Hamilton and Waller (1993) showed that women with eating disorders were more affected by fashion magazine photos, and overestimated their own size and shape after seeing them, than women not diagnosed with eating disorders.

Women in professions, or sports, which encourage thinness like long-distance running, ballet and gymnastics, show a high proportion of eating disorders, especially anorexia nervosa. This supports the idea that eating disorders can be triggered by environmental pressures. Of course, not all women in these professions develop eating disorders.

Schools of thought on the causes of eating disorders

Behavioural - Elaboration of the basic idea that attention and praise that weight loss reinforces dieting and process continues.

Psychoanalytic - Repression of sexual impulses or childhood abuse leads to anxiety expressed as an eating disorder.

Medical - Malfunctions in brain chemistry, linked with distributed levels of neurotransmitters.

Humanistic - Way of gaining controls over own life rather than parental control: high incidence in middle class, where there's a lot of pressure to succeed.

Cognitive - Distorted body image and irrational thinking lead to fear of gaining weight.

Note: it is most likely that there is no one single, simple answer as to what causes eating disorders - all of the possible explanations outlined above may be part of the story. Individuals may have different reasons for developing the same symptoms.

Eating disorders are characterised by very complex interactions of emotional and physical, problems. Because of this, eating disorders need to be treated by a combination of approaches.

Counselling Directory is not responsible for the articles published by members. The views expressed are those of the member who wrote the article.

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