Eating whole grains can increase nutrient supply and make flour comprehensive. Compared with vitamin B 1, the content of potassium and iron is only a quarter of that of whole grain. For example, compared with millet, the content of potassium and iron in rice is only one fifth, so eating whole grains can make people get more nutrition on the premise of eating a full stomach. People with a bad stomach should never refuse to eat coarse grains because of their rough appearance. As long as they choose good varieties, they will not increase the burden on the digestive system, but can help absorb more nutrients.