Why feel desire when you can change your thoughts?

Why feel desire when you can change your thoughts and therfor change your feelings and and actions? As I have been working on models, I realize that I can sit with desire and feel it. (Something I’ve done a lot of and still experience it a lot.) Or, like I did with the March homework, I can change my thought (I don’t like junk food.) and lessen desire greatly. I prefer the later, but I’m wondering if there is something magical about keeping our same desire filled thoughts, i.e. I love that food. That looks so good. so that we can learn to live with desire. I want desire out of my life. Is that wrong? It is just not a feeling I like. Is it okay to work on believing thoughts that lessen desire instead of sitting with it?