There is no doubt that many cases of candida get worse while the patient is on a "Candida diet".
While it isn't known exactly why these diets don't work, here's something else to consider - so called "Organic" veggies contain low dose Antibiotics .
"I think that a lot of people buying organic produce might be surprised to know that there might be Antibiotics in their veggies. The concentration of Antibiotic taken up in vegetables is very low, but it is real, and no studies have been done on the long term effects of persistent, low dose exposure to Antibiotics in humans."