Some statistics

Historical Background

Anorexia Nervosa and Bulimia Nervosa have existed for a very long time. A disorder apparently like Anorexia Nervosa was first written about by Physician and Minister John Reynolds in 1669 and Philosopher Thomas Hobbes in 1688. An accurate description of the disorder was written by Richard Morton in his Treatise on Consumption in 1694 describing a case seen in 1684. Recognition of the disorder as a clinical condition dates from work completed separately in London and Paris in 1873. Bulimia Nervosa was not recognised as a clinical condition until Gerald Russell's paper published in the UK in 1979. 

Epidemiology

The incidence of eating disorders

Although many studies have been undertaken, the published incidence rates vary widely because of the different methodologies used, the precise criteria of the study, and the size of the groups studied.

Within the United Kingdom estimates of prevalence and incidence will typically be higher in regions where specialist services for eating disorders exist. Changes in diagnostic criteria will also have an effect on estimates over time.
 
The incidence of new cases each year has been estimated as:
Anorexia nervosa: Up to 11 new cases per 100,000 population per year.
Bulimia nervosa: Up to 18 new cases per 100,000 population per year.
 
Whilst the incidence of anorexia nervosa appears to have remained fairly constant over time, that of bulimia nervosa appears to be increasing rapidly. Turnbull et al (1996) have suggested a fivefold increase in the incidence of bulimia nervosa over a five year period from1988 to1993.  

Prevalence

 The prevalence (the number of cases in the community at any one time) of any disorder will be related to both its incidence and duration. Both anorexia nervosa and bulimia nervosa tend to be longstanding disorders and so the prevalence is far greater than incidence. Prevalence rates for anorexia nervosa among young adult women has been estimated to be between 1 and 2% (Hsu 1991). A review of several studies of prevalence rates for bulimia nervosa among young adult women estimated that cases represent 1 to 3% of that population.

There remains relatively little information on the prevalence of Binge Eating Disorder and the category Eating Disorder Not Otherwise Specified (EDNOS). It seems likely that the prevalence of these disorders is higher than either anorexia nervosa or bulimia nervosa.

In 1992 the Royal College of Psychiatrists estimated that about 60,000 people may be receiving treatment for anorexia nervosa or bulimia nervosa at any one time in the UK.

However beat currently believes the number receiving treatment to be much nearer to 90,000, with many more people whose eating disorders have not been diagnosed, in particular those with bulimia nervosa. ( EDA 2000)

It is not only young women who suffer from eating disorders; men and women of all ages are affected. Estimates of the numbers of men in the eating disordered population varies with the criteria adopted and is thought to vary between 1:6 and 1:201. The most commonly used proxy is 10% of all cases of eating disorders will be male. ( EDA 2000)

Using the prevalence figures quoted above the combined total for people diagnosed and undiagnosed with an eating disorder in the UK is an astounding 1.15million.

The age range of people with eating disorders

Anorexia nervosa and bulimia nervosa are most common amongst girls and young women generally developing between the ages of 15 and 25 years, although they can occur at any age, even as young as 7 or 8 years. Bulimia nervosa is rare before the age of 13. With appropriate treatment recovery from an eating disorder can be achieved under five years, however eating disorders can persist throughout life and people may fluctuate between anorexia and bulimia nervosa. (EDA,1995)

The average age of onset for anorexia nervosa (AN) has been reported to be between 16.6 and 18.3 years (Theander, 1970; Halmi, 1974; Crisp et al., 1980) and according to different reports, the average age of onset for bulimia nervosa (BN) is between 17.7 and 21 years (Russel, 1979; Fairburn and Cooper, 1984; Mitchell et al., 1986)

However there are a number of beat members aged over 65, most of whom have long term eating disorders with a few who developed an eating disorder during or after middle age.

Approximately 10% of people with eating disorders are male, though among school children this may be as high as 25%. (EDA 1995)  In 2007 Girl Guiding UK, in partnership with beat, published a report on the findings of a survey carried out amongst Brownies (7-10yr olds) to find out what they feel about self-esteem and body image.  It clearly highlighted the concern that they feel about themselves 

http://www.girlguiding.org.uk/xq/asp/sID.818/qx/whoweare/article.asp

According to Government figures published in February 1999 by the Mental Health Foundation approximately 20 % of all adolescents have some form of mental health problem including eating disorders.

Clinical problems and mortality rate

 One of the primary complications of anorexia nervosa is loss of fertility. Treatment of the malnutrition usually reverses this problem but difficulties can remain throughout life. (Treasure 1997) Osteoporosis, or brittle bones, is another major health problem. Women who have had anorexia nervosa are at risk of developing fractures spontaneously or following minor amounts of trauma.

Erosion of tooth enamel, damaged saliva glands, an increased risk of heart disease and ruptured stomach are the primary complications of bulimia nervosa.

In addition to a range of health problems (such as heart, kidney, gastro-intestinal and fertility problems), anorexia nervosa presents itself as having one of the highest rates of mortality for any psychiatric condition, estimated to run at around 13-20 per cent per annum. (Howlett et al. 1995)

The main causes of death are the complications of starvation and cachexia (abnormally low weight) as well as suicide.. Mortality rates for anorexia nervosa are significantly higher than for bulimia nervosa. In 20 per cent of cases, there is no clear cause of death. 

Further sources of eating disorder statistics

The Institute of Psychiatry is at the forefront of research into eating disorders in the UK.  Their website can be accessed here   

An excellent source of historical information on eating disorder statistics is:- Eating Disorders: Anorexia Nervosa and Bulimia Nervosa by Richard West published in 1994 at £5.00 by the Office of Health Economics, 12 Whitehall, London, SW1A 2DY sadly now out of print.

The European Eating Disorders Review and The International Journal of Eating Disorders both published by John Wiley and Sons Baffins Lane Chichester PO19 1UD Tel 01243 779777.