Eating disorders are characterized by excessive and persistently disturbed eating or eating-related behaviours that lead to changes in the person's consumption of food to a degree that is harmful to their health and well-being.
Every individual is different, but common signs of eating disorders can include:
- Preoccupied with body appearance, weight and food
- Distorted view of their body
- Extreme dissatisfaction with their body
- Intense fear of weight gain
- Becoming irritable and/or withdrawing from friends and family
- Anxiety around food or meal times
- Feeling a loss of control around food
- Excessive dieting, binge eating or exercising
- Use of laxatives or vomiting (e.g. frequently going to the bathroom during or after meals
- Avoidance of social situations involving food or wanting to eat alone
- Developing rigid beliefs, patterns or rituals around food (e.g. only eating certain foods, insisting on eating at a certain time, cutting food up into small pieces)
- Excessive body checking behaviours (e.g. repeatedly weighing self, pinching waist)
- Change in clothing style (e.g. wearing loose fitting clothing to hide weight loss)
- Secretive behaviours around food (e.g. hiding food, throwing food out)
- Rapid weight loss or fluctuating weight
- Difficulty concentrating
- Lethargy and low energy levels
- Sensitivity to cold, even when it is warm
Eating disorders include anorexia nervosa, bulimia nervosa, binge eating disorder, and other specified feeding or eating disorder (OSFED).
Onset, prevalence, and burden of eating disorders
Eating disorders are common in young people, especially in female adolescents and young women, although males can also be affected (1). In their lifetime, about 0.3% of adolescents aged 13 to 18 years have anorexia nervosa (same % for males and females), 0.9% have bulimia nervosa (males 0.5%; females 0.9%), and 1.6% have a binge-eating disorder (males 0.8%; females 2.3%) (2).
While the prevalence of eating disorders appears low in the general population, it has been suggested that previous studies that used strict diagnostic criteria (e.g. from the DSM-IV) failed to accurately identify many young people with anorexia nervosa or bulimia nervosa (2). Instead, many of these individuals were diagnosed with eating disorder not otherwise specified (EDNOS), which was a broad category that covered clinically significant eating disorders that did not meet diagnostic criteria for anorexia nervosa or bulimia nervosa. Therefore, the actual prevalence of eating disorders is likely to be considerably higher than previously estimated. The latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) has addressed this issue by implementing substantial changes to the diagnostic criteria of eating disorders (for example, reducing the frequency of binge eating and compensatory behaviours that people with bulimia nervosa must exhibit, from twice weekly in DSM-IV to once a week in DSM-5) (3).
Eating disorders are a serious, potentially life-threatening mental health illness and can have significant physical and emotional effects. People with eating disorders can have reductions in cognitive function, emotional changes and may stop participating in their normal activities of daily life (4).
Young people with eating disorders are over ten times more likely to die prematurely than their peers without an eating disorder (5-7). This increased risk includes increased risk of suicide (8) and serious physical health issues arising from effects of bingeing, purging and starvation on the body's organs and metabolism.
In Australian females aged 15-24 years, bulimia nervosa and anorexia nervosa are the eighth and tenth leading causes of burden of disease and injury respectively (9). In young Australian females aged 12-24 years, eating disorders account for 14% of hospital admission for a behavioural or mental disorder (second only to depression, which accounts for 19% of admissions) (9).
The beginning of adolescence and the late teens are peak periods for people with eating disorders to experience their first symptoms, although eating disorders may first occur at any age. Anorexia nervosa is most likely to occur between the ages of 13 to 18 years, while bulimia nervosa usually occurs later, with the ages from 16-18 years having the highest risk of onset (10). Binge-eating disorder is more likely to have a later onset, in the early to mid-20s (11,12).
It is common for eating disorders to co-occur with other mental health and substance use disorders. It has been estimated that 56%-95% of individuals with an eating disorder meet diagnostic criteria for at least one other mental disorder (13). These often include anxiety, depression, and substance abuse (13,14).
Possible risk factors for developing an eating disorder include (15-17):
- Genetic vulnerability and family history
- Being female
- Body dissatisfaction or elevated weight/body shape concerns
- Negative evaluation of self
- Idealization of thinness
- Dieting (Australian adolescent females who diet at a severe level are 18 times more likely to develop an eating disorder within 6 months (18))
- History of sexual abuse and other adverse experiences