Thanks Dee. I don't think that's the case with Mazy cat. I am not replacing food with fat, I am adding fat. And I am adding only about 3% at the moment (goal is 6%). Fat increases motility, one, and the leaner meats she is getting for supper/bedtime meals may be why I am having trouble keeping her weight stable.
She didn't finish her breakfast because she had a fur blockage. (7 days since the last one) If I had insisted, she would have eaten it, and then puked everything up. (as happened a week ago) Everything except the fur that is, because that was already too far down, lodged in the passage between stomach and intestine..
She was eager for lunch, so I am guessing the thing had started to move by then. The added SEB in her lunch provided the mucilage to help it move, and after her supper pre-meal she pooped it all out.