I am beginning to suspect that it is surprisingly common for intelligent, competent adults to somehow make it through the world for a few decades while missing some ordinary skill, like mailing a physical letter, folding a fitted sheet, depositing a check, or reading a bus schedule. Since these tasks are often presented atomically - or, worse, embedded implicitly into other instructions - and it is often possible to get around the need for them, this ignorance is not self-correcting. One can Google "how to deposit a check" and similar phrases, but the sorts of instructions that crop up are often misleading, rely on entangled and potentially similarly-deficient knowledge to be understandable, or are not so much instructions as they are tips and tricks and warnings for people who already know the basic procedure. Asking other people is more effective because they can respond to requests for clarification (and physically pointing at stuff is useful too), but embarrassing, since lacking these skills as an adult is stigmatized. (They are rarely even considered skills by people who have had them for a while.)
This seems like a bad situation. And - if I am correct and gaps like these are common - then it is something of a collective action problem to handle gap-filling without undue social drama. Supposedly, we're good at collective action problems, us rationalists, right? So I propose a thread for the purpose here, with the stipulation that all replies to gap announcements are to be constructive attempts at conveying the relevant procedural knowledge. No asking "how did you manage to be X years old without knowing that?" - if the gap-haver wishes to volunteer the information, that is fine, but asking is to be considered poor form.
(And yes, I have one. It's this: how in the world do people go about the supposedly atomic action of investing in the stock market? Here I am, sitting at my computer, and suppose I want a share of Apple - there isn't a button that says "Buy Our Stock" on their website. There goes my one idea. Where do I go and what do I do there?)
Are you sure about that? Wikipedia's Nutrigenomics page seems to reference a lot of articles on documented gene-nutrition interactions, incuding the effects of nutrients on genetic expression.
I don't think SWAMI actually needs that many pieces of data to make strong recommendations; it claims to be using only 225 of the nutrients or substances found in 800 foods as a basis for its suggestions.
As I understand it, it's essentially doing something like, "people with this set of genes tend to have these problems; these nutrients tend to help with that kind of problem, these others make it worse -- so rate the foods containing those nutrients up or down accordingly..." and then it computes a total score for each food, and uses various cutoff levels to rank the food as "good", "bad", or "meh". ;-)
IOW, it's not using a massive array of studies on individual foods' effects, but rather, a scoring system based on known nutrient-genome-health correlations. And statistical prediction rules can easily outperfrom human experts, so it shouldn't be especially surprising that you could get some pretty good results out of less than "an awful lot of data".
On my epistemically rational side, I would certainly like to see more references myself. D'Adamo's book and software describes many kinds of "this does this to that and is related to gene XYZ-123" things that cause my brain to go "[citation needed]" -- i.e., I would really like to have a better idea of what his epistemology for all this stuff is, besides, "we studied it in my lab".
On the other hand, my instrumentally rational side has been happy enough with the results from following the book's recommendations so far, to be willing to buy the full kit. The interesting question will be whether I can lose more than the typical "20 pounds and then start regaining" that happens when people switch to new diets, and that will take a bit longer to determine.
(OTOH, I'm already about 20 pounds down from my last major dietary change about 8 months ago... so perhaps any further weight loss will be a good sign.)