People suffering from anorexia nervosa are starving themselves. They have an intense fear of putting on weight/of being fat. They take strict control of their eating, so they become obsessed with food, counting calories and working out elaborate ways of avoiding food and restricting their food intake.

They may also try to lose weight by excessive exercise, using slimming pills, and/or by various purging methods, e.g. vomiting or using laxatives.

The diagnostic criteria used by the NHS:

Symptoms include:

Some observable signs:

Some people with anorexia also purge to keep their weight low – see bulimia for the problems caused by vomiting and laxative use.