If fat "lines the intestinal walls, blocking sugar's uptake into the blood stream"...
...then how/why would the body "exhaust itself trying to remove sugar from the blood?"
This sounds familiar--were you reading Doug Graham? Personally, I've found the opposite of what he says to be true.
Most people do well by eating good fats and oils on the candida diet, like olive oil, coconut oil, fish oil. The notion that "fat is to be avoided the most" is just wrong. Sugar and flourwould be numbers 1 and 2.