Question: which grain is said to be the staple food of more than one-third of the world 's population
Answer: rice

title: Staple food
text: and tubers (4 percent). Most of the human population lives on a diet based on one or more of the following staples: cereals (rice, wheat, maize (corn), millet, and sorghum), roots and tubers (potatoes, cassava, yams and taro), and animal products such as meat, milk, eggs, cheese and fish. Regional staples include the plants rye, soybeans, barley, oats, and teff. Just 15 plant crops provide 90 percent of the world's food energy intake (exclusive of meat), with rice, maize, and wheat comprising 2/3 of human food consumption. These three are the staples of about 80 percent of the world population,