
The document you’ve linked talks about common perceptions and not much else, it’s short.
Anyway, nutrition is not just about amount of calories, one can consume a lot of calories but get scurvy.
BTW, the reason Soviet scurvy stats were not atrocious is that “sea cabbage” older generations remember (and hate, but it was there) being present in stores despite any deficit, and that all salt sold for food was iodised.
So - first, I’m not talking about amount of calories, second, I’ve read American food is notoriously bad nutrition-wise. Comparing USSR to Finland might be a better one.
Silage, but I’ve just remembered there was no selection involved, just mountains were a good natural barrier.
https://en.wikipedia.org/wiki/Heracleum_sosnowskyi
Until Soviet genial gigantic problem solvers did that again.