Is an eating disorder more about your mindset?

I know that eating disorders are to do with the way that you control what you eat, or the lack of control if you over eat, but is it possible that its to do with your mindset, even if you eat normally? EG: Anorexia: Person eats normally,but thinks that they need to lose weight and that they should stop eating to achieve this.

(This question is not meant to offend, and is not for personal use. I am studying a psychology course at the moment).

Thanks for all your answers