Protein is quite different from vitamins. Our bodies take vitamins from food, use them to aid in certain chemical processes, and then discard the vitamins. But our bodies take the protein from foods and keep it, using it to make new body cells or repair old ones.
Proteins are made up of substances called amino acids. There are more than 20 different amino acids, and they can combine in thousands of different ways to produce thousands of different proteins.
All plant and animal cells contain amino acids. When you eat meat or vegetables, you’re actually taking the amino acids from the cells of the food for use in your own body cells.
Your body doesn’t store amino acids for later use, so you have to take in protein every day. The best sources of protein are meat, dairy products, fish, peas, beans, nuts, and grains. But no single food item contains all the amino acids that the body needs.
The people of Australia and New Zealand eat the most protein per day, while those in Libya and Zaire in Africa eat the least!