I think we should be pointing to science - which to date it hasn't been adequately done relating to diet, to see what diet is optimal, and how that varies per group whether that's by blood type, DNA/ancestral data, or other - while taking in the particular sensitivities of each individual as part of the research vs. making the reference points based on a structure of scarcity of what was available based on what people could afford; also having an idea of a person's current health state, how healthy their GI tract is and overall system needs to be taken into account as to how they may or may not respond to different diets - including not limited to how we're only just beginning to understand how gut bacteria and within the whole GI tract can strongly impact outcome.