It’s interesting to see which grains predominate in different regions of the world
In southern China, South East Asia and India, it’s rice, of course
As we head north in China, rice gives way to wheat (noodles and dumplings)
And further north towards Korea, millet becomes more commonplace.
I imagine the same is true of Europe
In large parts of Africa, the Americas and parts of Europe maize/corn was the main crop with cornmeal and polenta featuring in the diet
The climate determines which crops are grown