What is the difference between whole grain and refined grains?

To provide the most health benefits, grain should be left whole. That means it still has all three of its original elements: the bran (outer shell), which contains fiber and B vitamins; the germ, which contains phytochemicals and B vitamins; and the endosperm, which contains carbohydrates and protein. When the grain is refined, the nutritious bran and germ are stripped away, leaving you only the aptly named endosperm.

Whole grains are grains that have their entire kernel (bran, endosperm and germ) intact therefore retaining valuable nutrients.

Refined grains on the other hand are grains that have been milled and stripped off parts of their kernel therefore lowering their nutritional quality.