Its not just a matter of what converts to sugar but how fast it can be metabolized to glucose or fast burning energy. There is little glucose than can be metabolized from fat. Some glucose can be metabolized from protein. Obviously a lot of glucose can be metabolized from carbs.-----(Known as glucogenesis)
When we have little flora to inhibit pathogenic candida, candida will evolve to use any fat, protein, or carb for energy. Pathogenic Candida can produce lipase, protease, and enzymes to break down carbs. The idea is avoid foods that can speed up candida's metabolism or high glycemic foods. When the flora becomes wiped out or nearly wiped out candida becomes more and more effecient at whatever you feed it. In other words, the less the flora you have to inhibit candida the more it becomes efficient/ability to adapt at whatever food substance you give it.