Causes of Eating Disorders

Causes of Eating Disorders

It is sometimes argued that anorexia nervosa and bulimia nervosa are variations of the same abnormality and cannot be easily distinguished, many sufferers have experienced both types of disorder. Psychologists tend to explain anorexia nervosa and bulimia nervosa together.

The following factors can be involved:

  • Biochemistry
  • Genetics
  • Personality
  • Social and family environment
  • Media images and messages about food and dieting

Exercise for you to try:

Different schools of thought in psychology approach psychological abnormality in different ways. Eating disorders can be explained in medical, psychoanalytic, behaviourist, and cognitive or humanistic terms.

Drag-and-drop the name of the school of thought into the box under its explanation of eating disorders:

Install Flash

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.

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 that there might be a genetic factor.

Twin studies carried out on identical twins, brought up together, have shown a 50% concordance rate for anorexia nervosa, this suggests possible genetic factor.

The link is less clear for bulimia nervosa, studies of identical twins have shown concordance rates of 23%.

Genetic factors and social, environmental influences within a family are hard to separate. Some studies have shown evidence that family tensions may trigger eating disorders.

Anorexia and bulimia nervosa are most common 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.

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.

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.

  • Call a local help line or clinic for expert advice.
  • Understand possible causes of eating disorders, food alone is not the main issue.
  • Don't make judgements.
  • Try to offer, caring support and help the person feel valued for other qualities than looks.
  • A person with an eating disorder may not accept that they need help, family and friends will need to offer encouragement and information.
  • Find out as much as you can so that you understand what they are going through, but don't try to act an expert yourself.
  • Encourage the person to find something that they enjoy doing to channel their energy into.