All grains start out in their natural state as whole grains. A whole grain consists of the entire seed of a plant, which includes the edible parts - the endosperm, the germ, and the bran. To remain a whole grain, all three edible parts should remain intact at the same proportions.
What is a refined grain?
"Refined grain" is the term used to refer to grains that are not whole, because they are missing one or more of their three key parts (bran, germ, or endosperm). White flour and white rice are refined grains, for instance, because both have had their bran and germ removed, leaving only the endosperm. Refining a grain removes many of the nutrients that can be found in the whole version.
How many whole grains should be consumed per day?
The current 2015-2020 US Dietary Guidelines recommend six servings of grains per day with half of these grains being whole grains (approximately 48 grams). Most Americans get less than one serving of whole grains per day, meaning 99% of Americans are not getting the recommended amount. Source
One bowl of Quaker Old Fashioned Oatmeal provides 40 grams of whole grains, as well as 4 grams of dietary fiber.