Rice is the staple food of over half the world’s population. It is the predominant dietary energy source for 17 countries in Asia and the Pacific, 9 countries in North and South America and 8 countries in Africa. Rice provides 20% of the world’s dietary energy supply, while wheat supplies 19% and maize (corn) 5%.

Cooked unenriched long-grain white rice is composed of 68% water, 28% carbohydrates, 3% protein, and negligible fat (table). A 100-gram (3+1⁄2-ounce) reference serving of it provides 540 kilojoules (130 kilocalories) of food energy and contains no micronutrients in significant amounts, with all less than 10% of the Daily Value (DV) (table). Cooked short-grain white rice provides the same food energy and contains moderate amounts of B vitamins, iron, and manganese (10–17% DV) per 100-gram serving (table).

A detailed analysis of nutrient content of rice suggests that the nutrition value of rice varies based on a number of factors. It depends on the strain of rice, such as white, brown, red, and black (or purple) varieties having different prevalence across world regions. It also depends on nutrient quality of the soil rice is grown in, whether and how the rice is polished or processed, the manner it is enriched, and how it is prepared before consumption.