Module created March 2013 - Reviewed January 2020
This resource has been compiled by Dr Chris Price, Head of the Revalidation Support Unit, using a variety of sources. It includes references to the NICE guidance on eating disorders and a section on reference material contains links to material for professionals and patient information sites.
What are eating disorders?
The term eating disorder is used to define a number of conditions affecting adolescents and adults. Eating disorders cause significant morbidity and mortality, leading as they do to multiple medical problems associated with both the physical and psychological consequences. There are considerable social issues to be addressed in many cases as the family of the individual are a key part of the package of care.
They are broadly classified into:-
- Anorexia nervosa a psychiatric illness that describes an eating disorder. A combination of altered body image and in most cases extremely low weight may lead to an individual employing extreme measures to maintain or lose weight. Excessive exercise, a near starvation diet or the use of laxatives and diuretics may be employed by the individual.
- Bulimia nervosa this condition is characterised by repeated binge eating usually followed by measures to compensate. Self induced vomiting (either through stimulating the gag reflex or by ingesting medication is to induce vomiting e.g. ipecac), fasting and the use of laxatives and enemas may be employed by the individual.
- Atypical eating disorders; this refers to patients with disorders of eating that do not fit into the diagnostic criteria for anorexia or bulimia. Examples might include individuals that use vomiting or a laxative abuse to control weight but do not binge eat, or patients with very low body weight who do not meet the criteria for anorexia. Binge eating disorder falls into this classification.
The impact of eating disorders
Eating disorders taken as a whole are a common condition. Anorexia nervosa affects about 1 in 250 females and about 1 in 2000 males. Whilst most of these patients present in adolescence and early adulthood the condition is well recognised in later adulthood. Bulimia is far more common affecting up to 5 times as many individuals as anorexia. The numbers of sufferers of atypical eating disorders is not known; many patients do not come to medical attention but the numbers are thought to be greater than the numbers of sufferers of anorexia and bulimia combined.
The onset of an eating disorder is most commonly seen in adolescence. The impact on the physical development of the individual may be crucial in this growth phase, the impact on the educational and social development may also have far reaching consequences with many sufferers not reaching their full academic potential. Family life may be disrupted with further consequences for carers and siblings of sufferers. Patients with eating disorders often have depressed mood and are ambivalent to health care. Anorexia nervosa has the highest mortality rate for psychiatric illness in adolescence.
Access to appropriate healthcare is crucial. The services for patients with eating disorders vary across the country, early intervention appears to affect outcome however access to specialist services is not always possible locally. This patchy nature of services combined with the ambivalence of the sufferer may have negative consequences.
The outcome of an individual with anorexia nervosa is variable. Many sufferers do not access formal medical care and the prognosis in this group is unknown. A review of 68 studies published before 1989 showed that 43% recover completely, 36% improved, 20% develop a chronic eating disorder and 5% die from anorexia nervosa. The overall mortality in the studies varied from 0-21% from a combination of physical causes and suicide. An individual with bulimia has about a 50% chance of full recovery with 20% experiencing ongoing bulimia with a further 30% experiencing some symptoms but below the diagnostic threshold. Atypical eating disorders may have a higher remission rate than either anorexia or bulimia, however long-term studies are lacking in this condition.
Screening for eating disorders in general practice
In the UK the average GP will only have one or two patients who suffer with anorexia nervosa. The prevalence of eating disorders in young women may be as high as 5%. Patients with eating disorders consult more frequently than the norm prior to their diagnosis; this gives a window of opportunity to the GP. The very nature of anorexia increases the diagnostic difficulty for the GP; the patient may be secretive, dismissive and have ambivalence toward seeking health care.
It is impractical to screen the entire general practice population for eating disorders; however high-risk groups can be targeted using a simple validated questionnaire. An example of this is the SCOFF tool.