What does refined grains contain compared to whole grains?

Refined grains are processed to remove certain parts of the grain, specifically the bran and germ, leaving primarily the endosperm. This process results in a product with a finer texture and an extended shelf life, but it also significantly reduces the grain's fiber and nutrient content. Whole grains, in contrast, contain all parts of the grain—the bran, germ, and endosperm—retaining their natural fiber, vitamins, and minerals. Therefore, when comparing refined grains to whole grains, it is accurate to state that refined grains primarily consist of the endosperm, which accounts for the differences in nutritional profile between these two types of grains.