The World Health Organization stipulates that anemia is diagnosed on the basis of the amount of hemoglobin in the human body. Hemoglobin is the main component of red blood cells, which is mainly composed of iron ions and pearl proteins. The human body is rich in protein reserves but limited in iron content, therefore, most of the problems of anemia appear in iron ions. In terms of diet, it is recommended to prevent anemia by eating foods that are richer in iron, such as black fungus, matsutake mushrooms, animal liver, lean meat, eggs, oysters, scallops, purslane, cilantro, oilseed greens, mustard greens, and lentils, and to try to eat as little as possible of foods that inhibit the absorption of iron, such as high-fat foods, alkaline foods, and to drink less tea, coffee, and soya bean milk, as well as to eat fewer peach kernels, apricot kernels, kelp, and carrots. Patients with megaloblastic anemia anemia also need to eat fresh vegetables and fruits, and supplement vitamin B12 and folic acid.