For an average four-person family, a minimum 350kg of cabbages and 200kg of radishes are required during kimjang. A winter’s supply of the fermented cabbage dish also requires 3kg of garlic and 18kg of salt.

350kg/4people = 87.5kg/person 87.5kg/person / (0.25*365days in a season) = 0.96kg/person per day

That's actually quite a lot (granted I'm assuming the "season" is 1/4 of a year, and at that latitude it could be longer).

For the hell of it, that 200kg of radishes is another 0.55kg/person per day. ~3 pounds of low-caloric food per day might be plenty.