I was personally wondering the same thing myself (I’m glad the candida diet has alleviated my symptoms so much, but before moving forward, I’d like to know if it is in fact candida causing my problems and not some other food/additive sensitivity). However the thought process I had was to eat something that is a complete no-no if you have a candida overgrowth, but would be highly unlikely to provoke a reaction otherwise.
There are two problems with this line of thought, as far as I can tell. The first is that virtually everything will provoke a reaction in somebody, and who knows, that somebody could be me. The second is that when you suddenly change your eating habits, your body is bound to react. I’ve heard of bad reactions from switching to a low-carb diet, or from a raw diet to a cooked one, or vegetarians who accidentally eat beef broth soup and get sick. That sort of thing. I know for certain other species experience this. Anyone who has cats (especially older cats or breeds with sensitive stomachs) knows not to suddenly switch cat food brands, or risk some very messy consequences.
So while a water fast has the benefit that you cannot (within reason) react to clean water, it is a very sudden dietary change, and I imagine that in itself might spark a reaction of some type.
I’m very interested to hear what everyone else thinks. How have others with not-so-obvious symptoms (e.g. no thrush, no vaginal yeast infection, etc.) determined that candida was in fact the culprit, and not something else?