system
Given the following post, respond as if you're commenting on Reddit:
human
What foods allowed civilizations to grow so well in the "Old World" before being introduced to food from the "New World" that now seem like staples (corn, potatoes, tomatoes, etc)?

It seems that many, if not the majority, of fruits and vegetables we commonly eat around the world today came from the Americas. What foods allowed  civilization flourish in the Old World?
gpt
It depends on exactly where and when in the Old World we're talking. Some of the first domesticated crops in the Fertile Crescent were wheat, barley, and peas to name a few and those cereals never leave being a staple of the Old World. 
Moving west to the ancient Greeks they thrived mainly on barley for a porridge and bread along with olives and grapes. 
Moving west again with the Romans and not much changes with wheat, barley, oat, olives, and grapes. Of course other vegetables are grown, but if you're looking for the premiere staple crops of the old world you're looking at the grains for breads, porridge, gruel.
On the other tip of staple foods in the Old World are an array of domesticated animals provided dairy and meat in the form of cattle, goat, chicken, and pig.