It's worked wonders in N. Korea... Oh...
N. Korea - Iran ....... Apples and Oranges.
There is plenty of food aid to North Korea. The sanctions against N. Korea do not extend to food.
There is starvation in N. Korea that is found in the ‘hostile’ class of the 50 strata songbun system where the hostile class is at the bottom. Starvation of the hostile class is deliberately inflicted by the state which also prevents food aid from reaching this bottom class. The regime wants the hostile class to perish.
The NK hostile class is too small to overthrow the regime in N. Korea whereas in Iran, where 72% of the population is favorable to Americans, starvation would certainly result in an overthrow of the regime and especially quickly if supplied with weapons.