★Definition of coarse grains: "coarse grains" is relative to rice, wheat, white flour and other "fine grains" in terms of a name, mainly refers to products including corn, sorghum, millet, buckwheat, oats, oat, potatoes and a variety of beans. Coarse grains include foods such as nuts, corn and cereals containing fiber-rich complex carbohydrates. As the old saying goes, "five grains for nourishment", meaning that both coarse and fine grains are rich in nutrients, and eating them together is good for your health. Different varieties of grain, nutritional value is not the same, let's say that oats are rich in protein; millet is rich in tryptophan, carotene; beans are rich in high-quality protein; sorghum is high in fatty acids, and rich in iron; potatoes are rich in carotenoids and vitamin C