Water fasting does not work for people that have fungal candida. The fungal candida will start to produce enzymes that degrade tissue/cells for food. This is its natural instinct to survive/decompose matter. Someone who has mild yeast overgrowth might be able to get away with a water fast but it would be more to give the body a break from digestion or detoxify than it would be to downsize candida. Trying to starve candida can cause it to be more invasive and go fungal. Especially if someone has little good gut flora to keep candida in check/turning fungal.