Optimal experimental design is difficult. I’ve usually tried only one new food at a time. In retrospect, this was not optimal, especially near the beginning of the process. If you eat five foods you are unsure of, wait a week, and get no symptoms, then all five are fine. If you get sick, at least one of them was a trigger, but you don’t know which one, and it may have been more than one. Then you could try two of them at a time, and so on. Proceeding this way would get you more information faster, at an upfront cost of being more sick more often. There’s whole subfields of statistical theory devoted to optimizing this sort of process. For a certain sort of geek, using that would be a lot of fun. I am that sort of geek! But it didn’t occur to me to try this until a year into the process.3 And there are several reasons it would be difficult.4 So I still haven’t done i