Grain now refers to a wide range. In ancient times, rice, wheat, soybeans, corn and potatoes were called five grains. At the same time, it is customary to refer to grains other than rice and flour as miscellaneous grains, which also refer to food crops, so grains are also a general term for food crops. Now it is generally called food crops. In Huangdi Neijing, the five grains are called "japonica rice, adzuki bean, wheat, soybean and yellow rice", while in Mencius Teng Wengong, they are called "rice, millet, millet, wheat and oat", and in Buddhist sacrifices, they are also called "barley, wheat, rice, adzuki bean and flax". There is also a saying that grains generally refer to five crops, namely "hanging, rattan, root, horn and ear".

The grains mentioned in Huangdi Neijing are japonica rice, adzuki bean, wheat, soybean and millet, while the grains recorded in Mencius Teng Wengong are paddy, millet, millet, wheat and rice. In Buddhism, five grains are barley, wheat, rice, adzuki beans and flax. At present, it can be said that there are too many varieties of food crops to count. I think they can all be regarded as five grains, so we can see that five grains are a general term, not just five.

At present, it is advocated to eat more whole grains, because people's staple food is relatively single, mainly rice and wheat. However, due to the exquisite processing procedures now, wheat bran and crude fiber components in rice and wheat will be treated in large quantities, and dietary fiber, B vitamins, minerals and various trace elements in many food crops will also be lost. Therefore, if more kinds of whole grains can be added to rice and wheat, the loss can be supplemented. For example, add red beans, mung beans, kidney beans, black beans and so on. Sweet potatoes, pumpkins and potatoes can also be added to the white rice. Some potato foods, miscellaneous beans and coarse grains are simple to handle, and are also rich in various minerals and dietary fiber, among which B vitamins are also well preserved. Therefore, it can increase dietary diversity, supplement lost nutrition, and inhibit the absorption rate of fat, cholesterol and sugar, which is stable.