The primary advantage of consuming whole grains over refined grains lies in their higher nutritional value. Whole grains retain the bran, germ, and endosperm, which provide essential nutrients such as fiber, vitamins, and minerals. These components help regulate digestion, stabilize blood sugar levels, and lower the risk of chronic diseases like heart disease and diabetes. Refined grains, on the other hand, often lack these nutrients and can lead to unhealthy spikes in blood sugar. Thus, opting for whole grains is a healthier choice.