That would only work if there was a one-to-one correlation of autism with having a selective diet and it being the same diet for all. And diagnosing selective

That would only work if there was a one-to-one correlation of autism with having a selective diet and it being the same diet for all. And diagnosing selective diet by itself by just asking questions isn't that hard anyway, is it? If it was a cheatcode to a diagnosis I think we'd figured it out already.