Before people started farming, African hunters and gatherers ate mainly fruit (especially figs), with some meat and fish and seafood and eggs. They also harvested wild grain and nuts to eat. They got a lot of their fat from nuts and palm oil. By 7000 BC, people in North Africa also began herding cattle, imported from Central Asia through West Asia. People milked the cows and made yogurt and cheese.
Around 6000 BC, as the climate changed and the Sahara Desert gradually took over the grasslands, it got harder to get food and so some African people began to farm some of their food. By 4000 BC, Ethiopians and Eretrians had domesticated a grain called teff, and in Nubia people had domesticated millet. In North Africa and Egypt, people farmed millet too, but also, the wheat and barley, lentils and chickpeas that had already been domesticated in West Asia. So these people began to eat mainly pita bread and porridge and barley soups, like the people of West Asia. People in Egypt also made their barley into beer.
In the rain forests south of the Sudan, you couldn’t grow any kind of grasses, because it was too wet and jungly.
A Taste of West Africa (Food Around the World) by Colin Harris