Understanding eating disorders

Anorexia nervosa is a life-threatening mental illness characterized by behaviours that interfere with maintaining an adequate weight. It usually involves persistent restrictive eating, a powerful fear of gaining weight or becoming fat, and a distorted perception of one's own body. Many people also have little awareness of how serious the illness has become.

An array of biological, genetic, social, and psychological factors influence its onset. Anorexia is not limited to any one gender, age, or body size, and many people appear well on the outside while hiding the severity of their illness. Early intervention significantly improves outcomes.

Bulimia nervosa is a life-threatening mental illness characterized by periods of food restriction followed by binge eating, with recurrent compensating behaviours such as purging or further restriction.

People living with bulimia are often deeply ashamed and work hard to hide these behaviours. They may be at a body weight that others read as typical, which is one reason the illness is so often invisible. Compensating behaviours such as purging carry serious physical risks, including dehydration, damage to the mouth and esophagus, and imbalances in the body's minerals and salts. It responds well to treatment and support.

Binge eating disorder is a mental illness that can seriously affect both psychological and physical health. It is characterized by recurrent episodes of eating large quantities of food, followed by shame, distress, or guilt.

It is different from ordinary overeating, which most people do on occasion. Binge eating is less common and is marked by real psychological distress and a sense of loss of control. It is not about willpower or discipline, and unlike bulimia it does not involve regular compensating behaviours. It affects people of all body sizes and is often under-recognised. Treatment exists and it works.

ARFID is characterized by severe limitations in the amount and/or the types of food a person consumes. Importantly, and unlike anorexia nervosa, ARFID does not involve distress about body shape or size, or a fear of becoming fat. It can still severely compromise growth, development, and overall health.

ARFID often begins in infancy or childhood and may be linked to sensitivities to the texture, colour, or smell of food, or to a frightening food-related experience such as choking. It is not the same as ordinary picky eating.

OSFED refers to atypical presentations of anorexia nervosa, bulimia nervosa, binge eating disorder, and other eating disorders. A person may meet many, but not all, of the criteria for another diagnosis.

These presentations are equally serious and as potentially life-threatening as the more typical ones. Examples include atypical anorexia, in which all features are present except that body weight is not below the expected level; sub-threshold bulimia or binge eating disorder, where episodes occur less often than the diagnostic threshold; night eating syndrome; and purging disorder. Many people are first diagnosed with OSFED, and the designation never diminishes the harm of the illness or the need for treatment.