I smoke grass and drink barley grass so no surprise if they did eat grass.
But i know they eat anything because some are starving to death.
Inside North Korea: Starvation and death - YouTube

North korean saying she eats grass video below .PLUS i suggest you watch all videos and you will see how good north Korea is..

Video for people starving in north korea▶ 2:33
https://www.youtube.com/watch?v=qTGxeO810DI

North Korea - Starving Korean People's Army Soldiers - YouTube
Video for people starving in north korea▶ 0:53
https://www.youtube.com/watch?v=wvy_Xi4t2P4

Video for North Korean Orphans Open Up About How They Survive - Real Stories▶ 6:13
https://www.youtube.com/watch?v=cUxIRSdc5y8

North Korea Cannibalism documentary film 2015 - YouTube
Video for north korea cannibalism▶ 19:44
https://www.youtube.com/watch?v=DqkGdLiCUCU

Undercover in the Secret State - YouTube▶ 42:21
https://www.youtube.com/watch?v=XJAaGQnGjbg