That book by Rupert Sheldrake re "7 Experiments..." has the most fascinating look at some of the fascinating ways that scientists indulge in quackery, deception, unscientificism and general self-serving stuff (like the rest of us) that essentially makes the term "scientific" laughable.

Then he wades into the fact of the observer affecting the outcome. Then the difficulty and unlikelihood of most scientific stuff being ever checked out by peers, then the business of being afraid of anyone seeing their "lab notes".

But what about people in the Palaeolithic era who lived in the Arctic where it is 6 months night?

AFAIK there isn't much vitamin D in fat of the land mammals.
Duck egg yolks are quite good, as they contain 6 time more D than chicken ones.
But my main source is Blue Ice - 2000 IU a day

Brussels sprouts taste foul when cooked, and are a notorious part of really awful boarding-school-dinners. I know they are pretty tasteless when raw, as I foolishly ate some thawed ones a few times as a child. Egg-plants? They are always cooked, I seriously doubt they are that pleasant to taste when raw, either. I know for sure that raw lettuce could never be a solid staple as it's pretty tasteless unless one adds lots of sauces onto it(adding sauces is not very Instincto a habit!).

What it boils down to is that unsuitable non-palaeo foods like rice usually need to be cooked and have sauces added to them to make them more palatable. But the whole point of Instincto is to avoid all processing.