There could be no hunger plan for the reason, that any government which ends up resorting to it would not won the war. Trying to starve the Jews locked up in Ghettos was going too slow for Nazi tastes, hence death camps. Starving entire USSR would go on even slower.
Genocides are expensive. Its easy to say "we'll fuel our war effort by pillaging and grabbing all their food!" that worked in pre-industrial eras where armies were mercenaries paid mostly in plunder.
Hunger plan seems suspiciously like ex-post facto justification. Remember that OTL, even in Germanic/Aryan countries like Netherlands or Denmark, a lot of people starved, especially in later half of war.
- My fuhrer, we are running out of food to feed out own civilians. Now that we are invading USSR, situation exacerbates due to overextending of our logistics.
- (Oh crap, this is so embarrassing, I am supposed to be all-knowing, what should I say.. wait, got it) Don't be ridiculous, well just grab all their food. Let Slavic sub-humans starve, its all part of my cunning plan.
Initially Germans mostly wanted to just conquer, not exterminate. Killing off a lot of people in process was just non-problematic side-effect. Final solution was accelerated as response to realisation they'd fail to conquer Europe: "Can't conquer lebensraum, but can still kill the Jews. One out of two isn't that bad."
There was ideological component, but most of time ideology did not really lead Nazis, it just rationalised their accidental bumbling around.
How did they justify to themselves invading Norway? Easy peasy, they said Norwegians were not spiritually Aryan. Their culture irredeemably corrupted by decadent Anglos. Hence, not our friends even if look Aryan.
In unlikely event of total victory in the East even with food shortages, Lebensraum ends up a net drain. Believe it or not, conscripting German farmer to travel thousand of kilometres, so he could beat up half-starved ex-kolchoznik to grow food for him, conscripting another one to make military supplies for him, and another one to transport all that stolen food back to Germany, and another one to guard trains from partisans, is less effective agriculture than just staying home and growing your damn potatoes yourself.
Hence, as Germans begin to starve as they keep throwing men at the east to kill real or suspected or potential partisans, hunting peasants who hoard all food they can, while Soviets starve to death so damn slowly, they look to a solution. And being Nazi with one directional minds, they can come up with only one solution.
So then Nazis remember that those fat disloyal French are stuffing themselves on frogs and snails while listening to de Gaullist radio propaganda, even as good German men fight on empty stomachs.
So they come up with another of their bullshit, this how French are mongrelised race with irredeemably high admixture of Jewish and Arabic blood.
Enter Hunger Plan West. French are told "let them eat cake". Then when it works as badly as suspected, so later on Belgians are added to the list, then, Dutch, then Danish, then someone decides that Alsatians aren't really German (French admixture! race traitors!), so they don't need to eat.
Finally WAllies invades in late 1944, or early 1945. By this point, the comparatively uneventful occupation of Western Europe is mostly distant memory, and Germans have their hands busy from Atlantic to Volga.