What is the theme in Staying Fat for Sarah Byrnes by Chris Crutcher?

Outcasts is a major theme. Sarah Byrnes was burned when she was only three, leaving her face and hands covered in disfiguring scars. Sarah Byrnes' father refused to have the scars repaired because he felt the scars would help her to be tough. Sarah Byrnes suffers a great deal of ridicule at school as a result of her burns, which leads to Sarah Byrnes developing a method of dealing with the pain. Sarah Byrnes stands up for herself, often taking punches and mean words, turning them around on the people who dish them out.