The outside layer of a grain like wheat or rice is called bran. If you need some fiber, avoid the chocolate chip muffin and opt for the bran muffin instead.
Most of wheat's nutrients are in its bran and germ, which are parts of an unprocessed cereal grain. When wheat is processed into white flour, the bran is removed. That's too bad since there are B vitamins, protein, iron, and important fatty acids in bran (all of which is stripped away when grain is milled or refined). White rice, for example, is rice with the bran and germ removed, while a grain of brown rice still contains both. In the sixteenth century, bran also meant "dandruff flakes." Yum!