The more simple the carbohydrate, the quicker it will feed the candida, so of course any type of sugars will feed it the quickest, then refined carbohydrates like white flour would be next followed by other grains and starchy vegetables like potatoes. But just because something feeds candida doesn't mean you can't eat it and still keep yourself healthy. For example, I eat white basmati rice and I feel very good on this, but some people prefer brown rice and this will feed candida less. Some people got this idea in their head that grains are unhealthy and this is not true at all, even wheat that is properly grown and freshly ground is very nutritious. You said you do well on rice and amaranth, so just eat those these are very healthy.