[If you are in a rush and /or don't want to read everything, I always tend to try to make a conclusion section in my answers to have the mains points (without the stories and explanation though), so if you want a quick answer, go see that section, otherwise enjoy the reading :) ]
Hello there, I'm finally taking time to answer that question that I saved a long time ago.First of all two disclaimers :
- I'm French and my answer and sources will be focused and from French perspectives, I can't answer you for the other occupied part of the world (due to a lack of knowledge about them). My primary source will be what my grand-parents told me about the war (I really need to share with Reddit the recorded story my grandma made for us), the different stories/witnesses I heard about from a French radio show (Hondelatte Raconte) and the French website Mémoire de Guerre.
- Second disclaimer is about the impact of the War itself : while the war was awful, it's important to remember that the stories told and more popular are usually extreme. Most of the country weren't on or next to the front, so the war was more like a far away scary shadow than an actual doom on their doorstep.
Context
The main thing is that each one of the occupied people were affected by the war in different ways. If you were living in a city you would suffer way more food problems than if you were in a rural area. It's important to note that the Rural Exod in France happened only after 1945, so during the war most of the population was still in rural areas.The impact of the war on the food is not the same throughout time, and change according the time and the zones occupied (France was occupied in the North directly by the Nazis while the South was under a French puppet State whom collaborated with the Nazis : France de Vichy/Vichy France.The war itself took away a huge portion of the labor force, especially during those times were women couldn't work (the popularization and use of women in the labor force really happened in France because of the war), thus you would end up with a huge drop in productivity in the whole country. With men on the front or in prison, the production of food but also of everything else would drop. Another thing is that most of the production was focused on the "Effort de Guerre" (War Effort), so mostly focused on producing goods for the war (ammunition, tanks, weapons...).The occupation had different forms, given the numbers of cities and villages, the Nazi couldn't physically occupy everything in an efficient way, so some villages would rarely see Nazi in their street (but they would always show up here and there for different reasons), and they would rely a lot on local forces (most of the time French but always collaborative to the Nazi). So, when you had Nazis or extra people in town to oversee, occupy, those people would be another burden on a food side, they would have privileges on the food and were given (by obligation, not by choice and happiness) food and other goods from the inhabitants and factories.Another factor is the direct effect of the War : with the War the country wouldn't be supplied by its colonies or by trade, thus a huge drop in food importations.
The food during the War
The government quickly set up a system of Rations where people were given tickets at the beginning of the month by the authority to allow them to trade them for food and goods. Those rations were subject to change and did change throughout the occupation.The system also set up a categorization of the population, according your age and situation :
The website mentioned earlier provides an example to visualize the rations and its evolution ; an adult (A category) in 1938 consume in average 3.4Kg (7.5lbs)/month while in May 1941 he had the right to get only 350g (12.35oz)/month and in 1943 260g (9oz)/month.That's a point that my grandma mentioned a lot : meat was the most difficult food to find and also to keep. She told me that her mum gave her a chicken that they had (she was in a small village) to take to the butcher to cook/roast it. The butcher was one of the only one in the village who had the possibility to cook food for a long time, since he had fat (butter and other kind of fat were very rare and usually taken away by the authorities). Anyway, it took him a whole day to cook it and when my grandma went to get it back, the chicken was missing some pieces and most of all, the juice was mostly gone. They made that chicken last for a week (for a household of 6 people at that time).Another factor who tend to forget that has a direct impact on the food is the lack of gas and coal due to embargo and drop in productivity : with no gas, it was harder to go further to get food, and without coal it was very very hard to heat houses and even cook. Because meat was difficult to get, most people ate vegetables and people tried to replace the goods that were the most difficult to find (meat, fat, sugar, coffee, milk, bread, cheese...). Artichoke and rutabaga became popular to eat, sugar is replaced if possible by saccharin, coffee by chicory/succory.
Effects of the shortage
The first effect of the shortage is the huge lines/queues front of the shops that had some food/goods to exchange for rations tickets. A funny thing (on a psychological stand point) is that people would know if food was available by the length of the queues and avoid the stores with no people (it sounds counterproductive to me, but I also understand the idea behind it).Most people who had food (butchers, bakers, store owners) would hide their goods to protect and/or keep them (a butcher got caught hiding a pig in his bed in 1942 according to a news paper in East France).A lot of people in the city would try to go in rural areas to find food, and a huge network emerged during the occupation. People started to trade a lot, for everything! Communities (villages, neighborhood) would help each other as much as they could, they knew that together they could survive better rather than alone (wink wink to the theory in economy of the economies of scales, probably The Hand doing its job, right Adam Smith?). My grandma told me the story of that neighbor that got out just in time of her house (in PJ's) during a bombing, she lost everything, all she had was her PJ's ; the whole neighborhood took care of her even if they all were suffering from the lack of food.In the cities, people without friends or families in rural areas were suffering the most, and balconies, caves and other rooms turned into garden and livestock areas (especially the caves, good place to hide your chickens, rabbits and pigs from the Nazi, for a short time at least).Of course, as any other time of trouble the Black Market became a huge and real thing that the authorities tried to fight. People were asked to denunciate anybody who practiced it, propaganda was put in place implying that "the black market is killing the war effort and would lead to a worst situation."
In conclusion
People in France would eat what they could get, in one hand from their rations tickets in stores, and on another hand what they could cultivate, raise and/or trade (il)legally. Food was indeed hard to get by, and was without doubt the biggest impact for a lot of people of the war (they didn't see or hear the war, especially with a deliberate lack of communication). They would replace what they could with other products to get as close as possible as they could. Meat, bread, wine, milk (and its products like cheese), fat and sugar were the rarest of the food and highly valued,
I hope I managed to answer your question, and again that's only a view point on France, I can't talk for Belgium, the Netherlands and other countries. The Benelux would have been in a better situation in my opinion given their germanic culture (Hitler considered them better than the Latins), and I would believe that Poland would have been in a worst situation, especially the Warsaw Ghetto.And as a last side note about my grandma (one of my big source ;) ) is that during the war she was in Marseille (South) for a first time before moving to a small village more inland and less likely to be bombed by the Nazi or the Americans.