Hypothyroidism, or hypothyroidism, is a disease in which the body’s metabolism is reduced due to a decrease in the synthesis and secretion of thyroid hormones, or a lack of their physiological effects. According to its etiology, it is divided into three categories: primary hypothyroidism, secondary hypothyroidism and peripheral hypothyroidism. In addition to replacement therapy with thyroxine preparations (e.g. levothyroxine), dietary therapy is also an important part of the treatment. For hypothyroidism caused by iodine deficiency, appropriate amounts of seaweed, nori and sea fish are needed. Iodized salt, iodized soy sauce, iodized eggs and bread with iodine are available, but should not be consumed in excess. In endemic goiter areas, iodized salt can be used to prevent goiter. For women who give birth, it is more important to pay attention to iodized salt supplementation to prevent the offspring from developing cretinism due to maternal iodine deficiency. When stir-frying, it is important to note that iodized salt should not be put into boiling oil to prevent iodine from volatilizing and lowering the iodine concentration. Amino acids are the basic components of protein, and about 3% of protein is constantly renewed every day. In hypothyroidism, the renewal rate of small intestinal mucosa slows down, digestive juice secretion glands are affected, enzyme activity decreases, and general albumin decreases. Therefore, essential amino acids should be supplemented to supply sufficient amount of protein to improve the condition. Protein can be supplemented with eggs, dairy, meat and fish; vegetable protein can be complementary, such as various soy products and soybeans. Hypothyroid patients often have hyperlipidemia, which is more obvious in primary hypothyroidism, so the fat diet should be restricted. Daily fat supply accounts for about 20% of total calories, and limit the cholesterol-rich diet. Avoid cholesterol-rich foods, such as cream and animal brains. Limit high-fat foods, such as cooking oil, peanut rice, walnuts, almonds, sesame paste, ham, pancetta, and sweet cheese. Those who have anemia should be supplemented with a diet rich in iron and vitamin B12, such as animal liver, and if necessary, folic acid and iron preparations. Supply rich vitamins and ensure the supply of various vegetables and fresh fruits.