Some complementary and alternative medicine (CAM) practitioners blame common symptoms such as fatigue, headache and poor memory on overgrowth of the fungus-like organism Candida albicans in the intestines, sometimes called "yeast syndrome."

To cure the syndrome, they recommend a candida cleanse diet. The diet eliminates sugar, white flour, yeast and cheese, based on the theory that these foods promote candida overgrowth.

It's considered normal to find candida in the human gut (gastrointestinal tract), but an overgrowth of candida can exacerbate existing gastrointestinal diseases such as ulcerative colitis and Crohn's disease.

However, there is little evidence that dietary changes can improve the effects of a yeast overgrowth if you have these conditions. Doctors usually prescribe antifungal medications to treat yeast overgrowth, which is diagnosed by putting a small scope into your stomach (endoscopy) and taking a tiny sample of your stomach lining (biopsy).

Unfortunately, there isn't much evidence to support the diagnosis of yeast syndrome. And there are no clinical trials that document the efficacy of a candida cleanse diet for treating any recognized medical condition.

Not surprisingly, many people note improvement in various symptoms when following this diet. If you stop eating sugar and white flour, you'll generally wind up cutting out most processed foods, which tend to be higher in calories and lower in nutritive value.

Within a few weeks of replacing processed foods with fresh ones and white flour with whole grains, you may start to feel better in general. That, rather than stopping the growth of yeast in the gastrointestinal tract, is probably the main benefit of a candida cleanse diet.