We all have fat in/on our abdomens, she may have just been stating a fact not realizing your feelings about
it, and having to take prednisone on top of it. Even when I was 115 lbs. and 5'5" (a long time ago, lol), my surgeon told me to go on a diet before surgery because my belly fat would make it harder to heal. I was very upset at the time, but he turned out to be one of my favorite doctors ever.
That said, the portion control comments were over the limit. She "should" understand what you're going through, if not, maybe she's not the right doctor for you.