Alright, so there’s been 21 reports of vomiting since I created this thread about a month ago (7th of September). Of those, 32% are accounts that can be shown to be established users. See the spreadsheet I put together here.
I’m not seeing evidence that these non-established accounts are sockpuppets. The narrative voice and character differs between the posts but the general symptoms match those described by the established users. I suspect that many of these users are registering because they were researching their symptoms online. I do want to point out that a google search for vomit food bar has this thread at the top, so it wouldn’t be hard for non-forum users to find (and then register).
Whatever the status of the accounts, 60% of people reporting issues say that they consumed a certain number of bars successfully (at least 2) without any kind of reaction, and then later had strong vomiting. That fact on its own is one of the more significant findings, and should be considered before writing off reactions as allergies to specific ingredients in the bars.
So far, I think @rlpowell has summarized the problem most succinctly:
[I]t’s not the bars by themselves, it’s not an allergy (because I had a bunch and I was fine); it’s some combination of the bars and particular people under particular circumstances.
He also suggests a vitamin overdose possibility:
I think what people are experiencing is a situational overdose of some vitamin that’s causing the effects in people who are sensitive to it.