A representative of the UN's World Food Programme, who has just returned from a visit to North Korea, said people were abandoning work and school to forage for sustenance.
"You see people of all ages going up into the hillsides with bags and sacks and coming back down with grasses. You see women on the seashores scavenging for edible seaweeds," said WFP's Gerald Bourke.
The agency has been forced to suspend cereal rations to more than one million people until at least August because of a lack of international donations.
Aid cut
In May, it had received only half the donations it needed and as a result cut its food distribution to 675,000 schoolchildren and 350,000 elderly people in order to be able to continue feeding those who were most vulnerable.
Those people not receiving aid were reliant on the inadequate government rations which most North Koreans get, Mr Bourke said.
Feeding North Korea
More than half the population is malnourished
45% of children under five are chronically malnourished
Reliant on food aid since 1995
They would each receive an average of 350 grammes per day - half the World Health Organisation's minimum recommended daily food intake.
"Teachers say attendance at school is down because children are out collecting wild foods," said Mr Bourke, adding that teachers themselves were also taking time off for the same purpose.
He said that he had asked a class of third graders, in the eastern coastal city of Kimchaek, how many had tasted meat in the last month.
"There were 25 pupils and only three of them had had meat in the last month," said Mr Bourke.
Lack of protein
"The basic staple at present is maize. Very occasionally an egg, a little bit of vegetable and that's it. No meat, no rice, no food. Very little protein."
Mr Bourke said that the slow donations were due to reasons including "donor fatigue", competing demands in war-torn Afghanistan and exasperation with Pyongyang's inertia over economic reforms.
He said that while additional food has been pledged since May, because of the time needed to transport it, the WFP would not be able to resume feeding those people without aid until August at the earliest.
And he warned that if further donations were not pledged immediately, any resumption in food distribution might only be temporary, and eventually, even more people might be cut off.