What causes an eating disorder?
The factors that contribute to the onset of an eating disorder are complex. No single cause of eating disorders has been identified; however, known contributing risk factors include:
- Genetic vulnerability
- Psychological factors
- Socio-cultural influences
There is some evidence that eating disorders have a genetic basis.
The genes that are most implicated in passing on eating disorders are within biological systems that relate to food intake, appetite, metabolism, mood, and reward-pleasure responses. It has been shown that this genetic influence is not simply due to the inheritance of any one gene but results from a much more complicated interaction between many genes and quite possibly non inherited genetic factors as well.
The biological causes of eating disorders are not well understood. This could be because the majority of studies are conducted during the acute or recovery phase of an eating disorder. At this time, there are physiological changes occurring in the person as a result of their eating disorder behaviours which can affect the findings of the studies. Studies conducted at the onset of an eating disorder could show different results.
Research into Anorexia Nervosa and Bulimia Nervosa specifically, has identified a number of personality traits that may be present before, during, and after recovery from an eating disorder.
- negative emotionality
- harm avoidance
- core low self-esteem
- traits associated with avoidant personality disorder
Specific additional personality traits may be associated with each type of eating disorder. It is also important to include that prolonged starvation induces change in cognition, behaviour, and interpersonal characteristics. It can therefore be difficult to discern the psychological causes from the psychological effects of eating disorders.
Evidence shows that socio-cultural influences play a role in the development of eating disorders, particularly among people who internalise the Western beauty ideal of thinness. Images communicated through mass media such as television, magazines and advertising are unrealistic, airbrushed and altered to achieve a culturally perceived image of ‘perfection’ that does not actually exist.
The most predominant images in our culture today suggest that beauty is equated with thinness for females and a lean, muscular body for males. People who internalise this ‘thin ideal’ have a greater risk of developing body dissatisfaction which can lead to eating disorder behaviours.
Like most other psychiatric illnesses and health conditions, a combination of several different factors may increase the likelihood that a person will experience an eating disorder at some point in their life.
Modifiable risk factors
It is possible to change some socio-cultural, psychological and environmental risk factors. The modifiable risk factors for eating disorders are identified as:
- Low self-esteem
- Body dissatisfaction
- Internalisation of the thin socio-cultural ideal
- Extreme weight loss behaviours
Low self esteem has been identified by many research studies as a general risk factor for the development of eating disorders. Strong self-esteem has been described as essential for psychological well-being and for strengthening the ability to resist cultural pressures.
Body dissatisfaction or negative body image
Poor body image can contribute to impaired mental and physical health, lower social functionality and poor lifestyle choices. Body dissatisfaction, the experience of feelings of shame, sadness or anger associated with the body, can lead to extreme weight control behaviours and is a leading risk factor for the development of eating disorders.
Body dissatisfaction is also linked to depression and low self-esteem and has been found to be widespread in adolescent girls in Australia.
Internalisation of the thin socio-cultural ideal
People who internalise and adopt the Western beauty ideal of thinness as a personal standard have a higher risk of developing an eating disorder.
Extreme weight loss behaviours
Disordered eating is the single most important indicator of onset of an eating disorder. Disordered eating is a disturbed pattern of eating that can include fasting and skipping meals, eliminating food groups, restrictive dieting accompanied by binge eating and excessive exercise. Disordered eating can also include purging behaviours such as laxative abuse and self-induced vomiting.
Disordered eating can result in significant mental, physical and social impairment and is associated with not only eating disorders but also health concerns such as depression, anxiety, nutritional and metabolic problems and weight gain.
While moderate changes in diet and exercise have been shown to be safe, significant mental and physical consequences may occur with extreme or unhealthy dieting practices.
Dieting is associated with the development of eating disorders. It is also associated with other health concerns including depression, anxiety, nutritional and metabolic problems, and, contrary to expectation, with an increase in weight.
Dieting and adolescents at risk
Puberty is a time of great change biologically, physically and psychologically. Teenagers are often vulnerable to societal pressures and can often feel insecure and self conscious, factors that increase the risk of engaging in extreme dieting behaviour.
The act of starting any diet increases the risk of eating disorders in adolescent girls. Research shows that young people who engage in unhealthy dieting practices are almost three times as likely as their healthy-dieting peers to score high on measures assessing suicide risk.
Studies in Australia and New Zealand have found:
- Approximately half of adolescent girls have tried to lose weight and practise extreme weight loss behaviours such as fasting, self-induced vomiting and smoking
- As many as 75% of high school girls feel fat or want to lose weight
- Young people who diet moderately are six times more likely to develop an eating disorder; those who are severe dieters have an 18-fold risk
- Among girls who dieted, the risk of obesity is greater than for non-dieters