About eating disorders

What are eating disorders?

An eating disorder is a complex mental illness that for some, can lead to severe and permanent physical complications, and even death.¹ Eating disorders are not a choice, they are serious illnesses.²

People experiencing some eating disorders may hold an inaccurate perception of their body size and shape, and attempt to control their weight and appearance through excessive dieting, exercising, and/or purging.^{3, 4}

There are several types of eating disorders – anorexia nervosa, bulimia nervosa, binge-eating disorder, avoidant restrictive food intake disorder (ARFID) and other specified feeding or eating disorders (OSFED).⁵

Anorexia nervosa (AN)

Anorexia nervosa is a serious and complex mental disease with psychiatric and physical symptoms.^6,7
The peak age of onset of anorexia nervosa is in early to mid-adolescence, but may occur at any age, including in childhood.⁸
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, to be diagnosed with anorexia nervosa, a person must display:⁶

- Persistent restriction of energy intake leading to significantly low body weight (within the context of the minimum expectations for their age, sex, developmental trajectory, and physical health);
- Either an intense fear of gaining weight, or of becoming fat, or persistent behaviour that interferes with weight gain (despite being significantly low in weight); and
- Disturbed perceptions of one’s body weight or shape, undue influence of body shape and weight on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.
Factors contributing to the development of anorexia nervosa are complex, and include a strong genetic component. Genes can be triggered by environmental influences, such as dieting or extreme exercise.^9,10
Personality traits of perfectionism and fear of failure, low self-esteem, and emotion avoidance are common among those living with anorexia nervosa.¹¹

Anorexia nervosa is characterised by the severe restriction of food intake, and generally results in significant (and dangerous) weight loss.¹¹
People living with anorexia nervosa often adhere to intense exercise routines.^12,13
In 2023, mortality rates were highest among those with anorexia nervosa versus other eating disorders.³ Medical complications are the leading cause of death, followed by suicide.^3,14
Anorexia nervosa claims the lives of approximately 450 people in Australia each year.¹⁵
Of those living with anorexia nervosa, around 90 people are expected to die from suicide.¹⁵

Bulimia nervosa (BN)

Bulimia nervosa is characterised by recurrent binge-eating episodes (consumption of unusually large amounts of food in a relatively short space of time) followed by compensatory behaviours.⁶
In bulimia nervosa, age of onset is more commonly seen in later adolescence and young adulthood.^16,17
According to the DSM-5 criteria, to be diagnosed with bulimia nervosa, a person must display:⁶

- Recurrent episodes of binge eating, characterised by eating in a discreet period of time and consuming larger volumes of food than what most people would consume during a similar period of time, and under similar circumstances;
- A sense of lack of control over-eating (e.g. a feeling that one cannot stop eating or control what, or how much they consume);
- Recurrent, inappropriate behaviours to compensate for over-consumption in order to prevent weight gain, such as self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise;
- Binge eating and inappropriate compensatory behaviours occurring at least once a week for three months; and
- Self-evaluation influenced by body shape and weight.

Accompanied by a sense of loss of control, binges are often followed by feelings of guilt and shame. Binges are often counteracted by self-induced vomiting, fasting, over-exercising and/or misuse of laxatives, enemas, or diuretics.^18,19
Eating disorders occur at any body size.¹⁷ People with bulimia nervosa can remain in the normal weight range, or be slightly under or over the average weight status.²⁰
Because some people mistakenly assume a person must be under-weight to have an eating disorder, bulimia nervosa and other eating disorders can often be missed, or go unnoticed for some time.^21,22
Around 200 people living with bulimia nervosa are expected to die each year.¹⁵

Binge-eating disorder (BED)

Binge-eating disorder involves episodes of consuming unusually large amounts of food, and a loss of control.^6,23
Similar to bulimia nervosa, the age of onset for binge-eating disorder most commonly occurs in later adolescence and young adulthood, and has a much more even gender frequency.⁶
Binge-eating episodes are associated with three (or more) of the following:⁶

- Eating much more rapidly than normal;
- Eating until feeling uncomfortably full;
- Eating large amounts of food when not feeling physically hungry;
- Eating alone due to embarrassment by how much one is eating; and
- Feeling disgusted with oneself, depressed, or very guilty after over-eating.

- Feelings of guilt, disgust and depression often follow a binge-eating episode.^{6, 23, 24}
Unlike bulimia nervosa, binge-eating disorder does not involve purging or other compensatory behaviours like excessive exercise. The illness can, however, involve sporadic fasting and repetitive diets, as well as weight gain.²⁵
The lifetime prevalence of binge-eating disorder in Australia is 2.20 per cent.³

Avoidant restrictive food intake disorder (ARFID)

ARFID involves the avoidance and aversion to food and eating, as a result of anxiety or phobia to certain foods.^6,26,27
It may also be as a result to heightened sensitivity to sensory aspects of food, such as texture, taste or smell, or lack of interest in food/eating secondary to low appetite.^6,26,27
ARFID is a serious eating disorder and more than just ‘picky eating’. Although distinguishing from fussy eating is difficult, adults and children with ARFID generally experience an extreme aversion to certain foods and have a general lack of interest in food or eating.²⁷
ARFID is more commonly present in childhood and adolescence, however it can occur in people of any age.²⁸
The main diagnostic feature of ARFID is an eating or feeding disturbance manifested by persistent failure to meet appropriate nutritional and/or energy needs associated with one (or more) of the following:^6,29
- Significant weight loss (or failure to achieve expected weight gain or faltering growth in children);
- Significant nutritional deficiency;
- Dependence on feeding via a tube or oral nutritional supplements; and
- Marked interference with psychosocial functioning.
ARFID can present in people on its own, but can also co-occur with autism, Attention-Deficit/Hyperactivity Disorder (ADHD) and anxiety.²⁷
The restriction of food can result in a lack of essential nutrients, leading to serious medical complications, including heart problems, osteoporosis, growth retardation and gastrointestinal issues.²⁷
Although similar to anorexia nervosa, people living with ARFID do not avoid food or restrict their diet due to a fear of gaining weight or concern over their body, weight or shape.²⁷

About eating disorders

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