By the way, doctor: How much protein should I eat?
Q. How much protein do I need every day? Does it matter what kind I eat?
A. Protein is essential. It forms the structure of the cells in our bodies and participates in almost every cell activity necessary for growth, development, and tissue repair. Protein also supplies fuel for meeting the body's energy needs. In the normal course of metabolism, the protein in our bodies is broken down into smaller molecules called amino acids. Some of these amino acids are used as fuel. Others are reassembled into protein molecules to replace the protein used each day by our cells.
The protein we eat is also broken down into amino acids. Some of these are "essential amino acids," so named because the body can't make them, and they must be obtained through food. We don't need to get all the essential amino acids in every protein source, but we do need all of them in our diets. We can't store amino acids, so we need to replenish them daily through the proteins we eat.