I did the same experiment to an extent blindly: after four years of stomach problems, I thought it was lactose intolerance. Leaving out milk helped quite a lot.

I did the same experiment to an extent blindly: after four years of stomach problems, I thought it was lactose intolerance. Leaving out milk helped quite a lot. Later I was tested, and found to not be lactose intolerant. Milk back on diet. Stomach problems reappeared, if just not that bad. Later on was diagnosed with something called "cereal allergy" (quite possibly not a real diagnosis, the army MD who explained this to me was preparing her dissertation on the subject). To wit, leaving out all cereal made all my stomach problems disappear. Now, what was the deal with the milk? I used to eat a lot of bread, and take milk with that. Leaving out milk, I inadvertantly left out bread as well, seriously limiting cereal in diet. This all happened in the first half of 1990s, long before the current popularity of the subject. Yes, not a real study (N=1 etc). OTOH, I would claim it was definitely blind for me.