Special planning of the "How Much Do You Know About Nutrition" series | One article explains everything related to high-quality protein

What is protein?

Amino acids are the basic units that make up proteins. So far, people have discovered only 20 kinds of amino acids that make up natural proteins. Among these 20 amino acids, leucine, isoleucine, lysine, methionine (methionine), phenylalanine, threonine, tryptophan, and valine are the eight amino acids that the human body must obtain from food. They cannot be synthesized in the body and are called essential amino acids. Protein is the scaffold and main substance that constitutes human tissues and organs, and plays an important role in the human body. That is, without protein, there would be no life activities.

What is high-quality protein?

High-quality protein refers to the protein in food whose amino acid pattern is close to that of human protein, and it is easily absorbed and utilized by the human body. Therefore, the number and type of essential amino acids in food protein become the standard for measuring the quality of protein. If the protein contains a full range of essential amino acids, in a suitable proportion, and in sufficient quantity, it is called a complete protein, also known as high-quality protein.

What are the main sources of protein?

The main sources of protein are animal protein and plant protein. Generally speaking, the nutritional value of animal protein is higher than that of plant protein.

Where can I get high-quality protein?

Eggs contain 11% to 14% protein and are an important source of high-quality protein. Milk (cow's milk) generally contains 3.0% to 3.5% protein and is the best source of protein for infants and young children.

Foods rich in animal protein include: livestock milk, such as cow's milk, goat's milk, and horse's milk; livestock meat, such as beef, mutton, and pork; poultry meat, such as chicken, duck, goose, and quail; eggs, such as chicken eggs, duck eggs, and quail eggs; and fish, shrimp, and crab;

Foods rich in plant protein include: soybeans, including soybeans, lima beans and black beans, among which soybeans have the highest nutritional value; in addition, dried fruits such as sesame seeds, melon seeds, walnuts, almonds, pine nuts, etc. have high protein content. Cereals are also plant proteins, and the protein content is generally between 7.5% and 15%.

Top ten high-quality proteins: eggs, milk, fish, shrimp, chicken, duck, lean beef, lean lamb, lean pork, soybeans (dry)

How can I eat to achieve the required protein intake?

Generally speaking, an adult can basically meet their needs by taking in 60g to 80g of protein every day. Therefore, we can eat a piece of meat the size of a playing card (raw meat is about 100g, and cooked meat is about 70g), drink two large glasses of milk (500ml) (a large glass of milk contains about 8-10g of protein), eat some beans (half a cup of various soybeans contains about 6-8g of protein), and eat a small amount of vegetables, fruits and rice, and we can get about 60-70g of protein, which is enough for an adult weighing 60kg.

What happens if you consume too little protein?

When there is insufficient protein in the food, adolescents will suffer from stunted growth and adults will feel fatigued, lose weight, and have a weakened resistance to disease.

What happens if you consume too much protein?

Excessive protein intake can lead to: 1. Damage to the intestines 2. Brittle bones 3. Increased burden on the kidneys 4. Fat accumulation

Protein is an essential nutrient for us. We should not only consume it every day, but also know how to eat it right and well. A scientific and nutritious diet is beneficial to our physical and mental health.

Author: Sun Wenyuan and Hu Mengdie, Department of Special Medical Care, Cancer Hospital, Chinese Academy of Medical Sciences

Review expert: Xin Xiaowei, nutritionist and deputy director of the Nutrition Department of Cancer Hospital, Chinese Academy of Medical Sciences