These disorders emerge when people (most typically girls and women, but some boys and men as well) either starve themselves even when they are very underweight (anorexia nervosa) or, alternatively eat huge amounts of food (binge) and then cause themselves to vomit (purge) – bulimia. Both disorders can involve the mis-use of laxatives.

Anorexia is particularly dangerous as persistent starvation affects organ function and can ultimately result in death. People with anorexia have disturbed body images in that they perceive themselves as fat even when they are skin and bone.

Bulimia can result in damage to the oesophagus, mouth and teeth due to repeated exposure to the corrosive nature of acidic vomit.