For Those Who Don't Understand.. Anexoria: Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, fear of gaining weight, and a strong desire to be thin, resulting in food restriction. Many people with anorexia see themselves as overweight even though they are in fact underweight. Bulima: Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging ( Vomiting ). Binge eating refers to eating a large amount of food in a short amount of time.