Starving people in North Korea are surviving (since per definition they are surviving if they are not dead). Doesn’t mean North Korean diet is something we should strive for.

So much this ^^^^^.

Average North Korean is now about 3 inches shorter than the average South Korean [0]. 70 years ago they were the same people with the same height... Both nations have very little in the way of immigration so this difference is all due to the environment (i.e. in this case nutrition).

[0] https://www.bbc.com/news/magazine-17774210