As far as I am concerned, your suggestion seems completely fine: “If the choices about what I eat belong to me…”
My personal, perhaps non-linguistic, problem is that conditional “If” at the beginning of the sentence. I know that choices about what I eat are mine, and pretty aware that they don’t belong to anyone alse. So, I feel that there is no need to remind myself what would happen if choices were mine… However, when I overeat, I don’t think about having the choice at all. So, would help (actually, it did the job for few nights ago) to remind myself to the fact that there is a choice. It seems that “Since the choices about what I eat belong to me…” would work perfectly for me. Does it make sense?