At present, only 150 plant species are used on a significant global scale; over 50% of the world's requirement for protein and calories are met by only three: rice, wheat and maize. - Millet

I would have to guess the runner-ups:

sweet potato, potato, cassava (tapioca) and bananas.


In my opinion, Sweet Potato is the best, but the only downside is that it is a musical fruit, like the beans. The more you eat, the more you toot!