The conclusion I have come to is that humans, when starting from an over-fed modern baseline, are robust enough to eat a totally shit diet for a couple months. This is also long enough to convince us it is worth blogging about.

I've only heard that about carnivore diets, and it makes sense to me. Where can you find all the nutrients necessary for a mammal to survive? In the body of another mammal, of course.

B12 is a pretty important one if you want to avoid the title of section 1 of this article though.

And while butter contains b12, you'd probably have to be eating a few bars of it a day to get enough long-term.

That's my understanding.

The spudfit guy did only potatoes and a B12 supplement for a year. His claim was that he was getting everything else he needed from the potatoes.

You can pick one of the usual Native American crop patterns and get a solid set of vitamins. Potatoes + beans + squash or something like that, maybe with some corn. Cf. Mann's 1491. If you're going for a minimal veggie ingredient diet these new-world combos work well as a base, in part because potatoes are pretty much a superfood.

I did the SMTM study and they prohibited dairy. So I got my B12 from sweet potato.