1. Preferred fish and seafood

　　Fish and seafood are rich in protein, 15% to 22%, and their amino acid composition is relatively balanced, which is close to the human body and has a high utilization rate. The vitamin content of fish and seafood is comparable to or slightly higher than that of livestock and poultry meat. The fish oil and cod liver oil that people often eat are important sources of vitamin A and vitamin D. The mineral content of fish and seafood is 1% to 2%, which is higher than that of livestock and poultry meat, especially the contents of zinc, selenium, calcium and potassium are more prominent. Seafood and seafood are also rich in iodine. However, compared with livestock and poultry meat, the biggest nutritional advantage of fish and seafood lies in fat. The fat content of fish and seafood is generally low, ranging from 1% to 10%, with an average of about 5%, and is mainly composed of polyunsaturated fatty acids (this is similar to vegetable oils). Many marine fish and seafood also contain fat Two special polyunsaturated fatty acids-docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). DHA and EPA are ω-3 polyunsaturated fatty acids, and their basic functions are: ① prevention of dyslipidemia and cardiovascular and cerebrovascular diseases; ② regulation of immune function; ③ promotion of early life (fetus, infants, preschool children) nervous system development ; ④ It is related to the development of infant vision. A large number of studies have shown that eating fish regularly can reduce the incidence of cardiovascular and cerebrovascular diseases. Therefore, when conditions permit, fish and seafood should be preferred, an average of 50 grams to 100 grams per day.

　　 2. More "white" and less "red"

　　 "white meat" refers to white meat such as chicken, duck, birds, fish and seafood, but it does not Does not include white fat pork, fatty beef, etc. "Red meat" refers to the muscles, internal organs of pigs, cattle, sheep and other livestock and their products. The muscle color of the meat is darker and dark red. The main nutrient contents of common livestock and poultry meat are shown in Table 8-2.

　　White meat and red meat are not very different in important nutrient content (such as protein, vitamins and minerals), or have their own characteristics. The main difference between the two is in fat. Generally, white meat has lower fat content than red meat (except duck and goose), the ratio of saturated fatty acids is lower than red meat, cholesterol content is also lower than red meat, and the fatty acid composition of white meat fat is better than red meat. In order to avoid excessive intake of saturated fatty acids and cholesterol, under the premise of controlling the total intake (100 to 175 grams per day), more white meat and less red meat should be selected. The World Cancer Research Foundation recommends that weekly consumption of "red meat" should not exceed 500 grams. Combined with the requirements of the "Dietary Guidelines for Chinese Residents 2007" (approximately 700-1?200 grams of meat per week), we recommend that ordinary adults have a lot of white meat (including fish, seafood, chicken, duck, etc.) per week Red meat (pig, cattle, sheep, etc.) is not more than 500 grams. Anemia patients who need to supplement with heme iron should choose dark red meat, because the heme iron content is positively correlated with the red color of the meat.

　　3. Eat less animal offal

　　Animal liver protein content is high, fat content is lower than meat, such as pig liver protein content, only fat. Pig liver is also rich in vitamin A, B vitamins (such as vitamin B1, vitamin B2, vitamin B6, vitamin B12, folic acid, etc.) and trace elements such as iron, zinc, selenium. Therefore, pig liver has always been hailed as a "reasonable treasure house" of good quality and low price, and has been widely recommended. However, the shortcomings of pig liver are also obvious. Pig liver contains more cholesterol. 100 grams of pig liver contains 288 mg of cholesterol, which is twice as much as lean meat. In addition, when raising pigs with feed, drinking water and air intake of pollutants (such as heavy metals, residual pesticides), antibiotics, hormones, feed additives, illegally used substances (such as "Clenbuterol"-Clenbuterol ) Accumulates more in the liver (similar to other internal organs), much higher than muscle. Malignant incidents of Clenbuterol poisoning caused by eating pork liver or other internal organs are numerous. With the improvement of people''s living standards, meat, eggs, milk, etc. are becoming more abundant, and the advantages of pig liver in terms of good quality and low price are no longer prominent. Under the current living standards, most urban residents can completely meet the nutritional needs by ingesting the muscles of livestock, poultry and fish, and they do not necessarily have to eat pork liver. Pork liver should be evaluated scientifically, not only to see the rich nutrients contained in the liver, but also to see the potential food safety hazards in the liver. Therefore, we do not recommend eating more or more of the liver.