AFAIK the North completely overhauled their food production in the 90s which is why the loss of trade with China during COVID didn't trigger a famine - but they definitely lost a bunch of variety in their diets for that time which understandably caused problems. The energy problems though are on par with any other industrialized-but-poor nation, something that the DPRK has gotten better at dealing with but really can't solve under present conditions.

(as an aside the North's commitment to being food self-reliant is also one of the reasons their economic recovery in the 2000s was so slow - growing food in the North is really difficult and inefficient, which is why traditionally they've relied on food imports, but when that was no longer an option they had to dedicate a ton of labor and resources to doing it anyway which cannibalized labor and resources that were previously being used for heavy industry)