Grain

Grain is the harvested seed of grasses such as wheat, oats, rice, and corn. Other important grains include sorghum, millet, rye, and barley. Around the globe, grains, also called cereals, are the most important staple food. Humans get an average of 48 percent of their calories, or food energy, from grains.

Nutrients. Grains are important sources of many nutrients, including complex carbohydrates, dietary fiber, several B vitamins, and minerals (iron, magnesium, and selenium).

Merriam-Webster tells us that a grain is “a unit of weight based on the weight of a grain of wheat taken as an average of the weight of grains from the middle of the ear.” Other sources reveal a similar definition, with the consensus being that grain refers to the weight of a single seed of cereal grain.