Food is very important. You can learn a lot of a civilization by its food.
I don't mean the style of cooking, but more the spread of different foods and the nutricients in it. In Europe the most common food is always grain. In Eastern Asia Rice and in the New World corn. Of those three grain is the least productive. You need four times the space as rice does to produce the same weight of food. And corn is even better. Stramnge thing is that the civs with corn didn't advance so quickly as Europe or Asia.
One of the main reasons for that is the lack of large mammals. No horses, cows or sheep. So no animals to carry much for you, drive you around or provide large quantities of food/milk/leather.
Another factor is the climatical boundaries. To travel from west to east or vice versa is a hundred times easier then from north to south. In west/east you stay in the same climate, and with north/south you pass severa climate-zones. The Americas are more a north/south continent then Eurasia is. So this limits the exchange of ideas, foods, technologies, and so forth. No Inca ever met an Aztec as far as we know today. But Rome and China had contact via the Scythian tradesmen.
So the spread of foods is a very good indicator how a civ survived, or didn't, and what contacts and achievements it had. The potatoe is the most important food in Russia. Czar Peter the Great learned of it from the Dutch when he visited Zaandam and the Dutch obviously learned it from Spanish traders from the New World. This tells a lot about the history of Holland, Russia and Spain, for example.
