The two world wars in terms of food security of Great Britain and its allies took place according to a similar scenario. As the British were dependent on outside supplies, had to rely on the United States and Canada. Those, helping the allies, also urged their citizens to be a bit more modest.
Well, the Germans actively obstructed supplies. The philistines were urged that every piece of bread is equally important as a bullet or a grenade, that home canning is a strategic issue, food speculators are enemies of the state, etc. Lets's see.