What is the most eaten food in the world?

Bread is the world’s most widely eaten food and has been part of our diet since the early times of mankind.

Most people in the United States, Canada, and in many European countries eat yeast breads. Yeast breads make up about 99 percent of the bread baked in the United States.

Flatbreads are more common in other parts of the world than in the United States. Most flatbreads are unleavened. They are made from batters or kneaded dough often cooked on
a stovetop rather than in an oven.
Examples: tortillas (Mexico), Jewish matzah, crepes (France), chapatis (India), mandarin pancakes (China), okonomiyaki (Japan) and pita bread (Middle East).

http://wellnessways.aces.uiuc.edu/pdf/ho_BreadsAroundWorld.pdf

"Rice feeds more people than any other plant species on Earth."

http://www.landofsixpeoples.com/news401/nc401133.htm

bread

www.ers.usda.gov/data-products/wheat-data.aspx#25184

From the USDA, here are production minus ending stock numbers for 2015:

Rice: 393,717,000
http://www.ers.usda.gov/data-products/rice-yearbook.aspx#57033

Wheat: 479,676,000
http://www.ers.usda.gov/data-products/wheat-data.aspx#25184

Bread is likely the answer.