Why is protein so important?
Protein (English: Protein) is one of the important components of human body, and all cells and tissues of human body contain protein. It has been proved that there is no life without protein.
How is protein distributed in the fetus?
Protein accounts for about 45% of fetal solid components. Protein is widely distributed in the fetus, and almost all organs and tissues contain protein. The distribution of protein in fetus is: muscle 50%, liver 10%, kidney 4%, plasma 1%~6%.
What the hell is protein?
Protein is a macromolecular organic compound composed of amino acids connected by peptide bonds and forming a certain spatial structure.
-Amino acids are the basic unit of protein. There are more than 300 kinds of amino acids in nature, but only 2 1 kind of amino acids make up protein.
There are nine kinds of amino acids, which cannot be synthesized by human body or the speed of synthesis cannot meet human needs, and must be provided by food. These amino acids are called "essential amino acids". (including: isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine and histidine)
What harm will be caused by the lack of protein?
1.？ When protein loses more than 20%, life activities will be forced to stop.
2.？ Adult deficiency symptoms: fatigue, weight loss, anemia, decreased immunity and stress ability, and decreased memory. In severe cases, emaciation and edema may occur. When the content of protein in plasma decreases, especially albumin decreases, nutritional edema will occur. Nutritional edema is the manifestation of energy deficiency, only protein deficiency.
3.？ Insufficient intake of protein during pregnancy will lead to small fetus, abnormal brain development, and even affect all organs of the fetus.
4.？ Insufficient intake of protein in childhood will lead to obvious short stature, emaciation and dysplasia. It is also possible that it is edema type lacking only protein and energy, which is characterized by normal height, but flabby muscles and cheeks like a full moon.
What harm will protein's excessive intake bring?
1.？ Studies have shown that kidney damage occurred after eating a high-protein diet for eight months, and 35% of the energy supply came from protein.
2.？ Studies have shown that a high-protein diet may lead to calcium loss in the body.
3.？ May be harmful to cardiovascular diseases.
How to judge whether there is a lack of protein?
1.？ Physical examination: body mass index. Body mass index = weight (kg) divided by height (m2), such as 50kg, height 1.6m, body mass index = 50/( 1.6X 1.6)=? 19.5。 A body mass index lower than 18.5 is a defect.
2.？ Biochemical examination (partial list only)
Blood index:
A.？ Total protein < 60g/L is deficient.
B.？ Albumin 30~35g/L is mildly deficient, 25~30g/L is moderately deficient, and ≤25g/L is severely deficient. When albumin is lower than 28g/L, edema will occur.
C.？ Plasma prealbumin 150~250mg/L is slightly deficient, 100~ 150mg/L is moderately deficient, and ≤ 100mg/L is severely deficient.
D.？ Transferrin 1. 5~2g/L is mild deficiency, 1~ 1. 5g/L is moderate deficiency, and ≤ 1g/L is severe deficiency.
Urine index: urinary creatinine (creatinine)
The reference value for men is 20 ~ 26 mg /(24 hours kg body weight) (7 ~18 mmol /24 hours).
Female 14 ~ 22 mg /(24-hour kg body weight) (5. 3 ~ 16mmol/24h)。
When protein is deficient, the content of urinary creatinine decreases. When urinary creatinine exceeds the normal range, it reflects excessive food protein intake or renal insufficiency.
How to make up for the low protein of pregnant women? What are the main food sources in protein?
1.？ Plant food (called plant protein)
Mainly from cereals, such as rice, wheat, corn and so on. Grain contains about 8% of protein, and its main component is gluten, which lacks lysine or has low lysine content (lysine is one of the essential amino acids for human body).
Due to the lack of essential amino acids, the utilization rate in the body is low, that is, the absorption rate is not high.
Followed by beans, such as soybeans and black beans. The protein content of beans is as high as 35%~40%, the amino acid composition is reasonable, and the in vivo utilization rate is high, that is, the absorption rate is high. It contains all essential amino acids needed by human body and is one of the high-quality protein.
Eat cereals and beans together, such as soybean milk with steamed bread. Can improve the absorption rate. Because beans are rich in amino acids that grains lack.
2.？ Animal food (called animal protein)
First comes from eggs, such as eggs and duck eggs. Egg contains protein 1 1%~ 14%, and its amino acid composition is relatively balanced, including all essential amino acids needed by human body. It is one of the high-quality protein.
Secondly, it comes from milk, such as milk and yogurt. Milk contains 3%~3.5% protein and is rich in casein, whey protein and lactoglobulin, which is the best source of protein for infants. It contains all essential amino acids needed by human body, and it is also an important source of high-quality protein for human body.
Finally, it comes from all kinds of meat, such as chicken, pork, shrimp, fish and so on. Meat contains protein 15%~22%,
It is rich in sarcoplasmic protein, myofibrillar protein and sarcoplasmic protein. The nutritional value of muscle protein is superior to that of plant protein, and it is an important source of human protein.
In order to improve the quality of dietary protein, animal protein and soybean protein are generally required to account for 30%~50% of the total dietary protein.
Now I'd like to share with you a recipe for pregnant women to supplement protein.
Evaluate the nutritional value of food protein, and comprehensively evaluate it from several aspects:
The content of 1. protein, such as rice 7%~9%, flour 10%~ 12%, oat 13%~ 15%, is obviously the best.
2. The extent to which it can be used by the human body after absorption. For example, 94 eggs, 85 milk, 83 fish, 76 beef, 74 pork and rice. Obviously eggs are the best.
3. Does the composition of protein contain essential amino acids? If it contains all essential amino acids needed by human body, it belongs to high-quality protein.
How does protein digest, absorb and participate in body metabolism?
1. After food protein enters the stomach and small intestine, it is hydrolyzed into amino acids and short peptides by various proteases and peptidases. Hydrolyzed amino acids and short peptides are transported to all cells of the body by carrier proteins in the intestine, and then transported to the fetus through the placenta, and then every cell, organ and hormone in the fetus is synthesized by amino acids and short peptides.
2. There is 1%~2% protein in human cells every day because of its "life span" and needs to be replaced. These protein are first decomposed into amino acids in the body, of which 70%~80% of amino acids and amino acids absorbed from food are recombined into new protein according to the instructions of genes, and then the intracellular protein is replaced. The remaining 20%~25% amino acids are excreted through urine and feces, or converted into glycogen and fat for storage in the body.
What are the functions of protein?
1.？ Constitute and repair tissues and organs
2.？ Physiologically active substances in the body, such as enzymes (necessary for digestion and metabolism, participating in the development and maturation of fetal cells, promoting the development of neurons and nerve regeneration) and hormones (such as assisting the fetus to secrete thyroid hormones).
3.？ Participate in the immune regulation of the body
4.？ Promote the absorption of minerals, such as casein phosphopeptides (present in milk) to promote the absorption of calcium and iron.
Supply the energy needed by the body.
? Therefore, if pregnant women want to supplement protein scientifically, they need to know how much protein they should take during pregnancy.