>Will you receive food as a guest at someones house?
I don't know what's the definition of "guest", but if you are an official guest at a German house like a friend or something, you will most definitely get food. I don't believe this map.
I think it's more about whether you automatically get offered food as a guest as a standard procedure or not. In Germany you either get invited for dinner explicitly or you'd have to ask for food if you're hungry, but of course you would get something in most cases. In Poland for example you just always get asked if you're hungry right after saying hello
When I was a child and visited the home of one of my friends, they would always invite me to eat with them. But to be fair, some of those friends were foreigners, so I don't know about a "biodeutsche" family.
You can't imagine how much I suffered. Especially in this base. In 2015 a recruit committed suicide with his service weapon so we weren't even allowed to have it on us permanently :(