Anorexia is characterised by a distorted body image, with an unwarranted fear of being overweight. Symptoms include trying to maintain a below-normal weight through starvation or too much exercise. Medical treatment may be required to restore normal weight. Talk therapy can help with self-esteem and behavioural changes. The main difference between diagnoses is that anorexia nervosa is a syndrome of self-starvation involving significant weight loss of 15 percent or more of ideal body weight, whereas patients with bulimia nervosa are, by definition, at normal weight or above.