Food Energy & Weight Loss

Below is an excerpt from Part Two of

The 2004 Multi-Diet

by Anderson A. Anonymous, M.D., Ph.D.

Protein is for Building

The body’s preference for protein is to use it to build and repair biologically active tissue (muscles and organs). You can get an intuitive idea of the importance of this function by realizing that ALL of your muscles and organs are “built” out of proteins (thousands of them). Further, it is well known by physiologists that the protein in these tissues is in a constant state of “turnover”, that is, the proteins are constantly being broken down, rearranged, and rebuilt. Why this happens is not clearly understood, but probably relates to a continuous “fine-tuning” of the tissues to the demands being placed on them and to the proteins from food which happen to be available.

The importance of protein for dieters is that muscles and organs are the only tissues that use energy. The energy from fat is what many of these tissues—particularly muscles—prefer to use. Therefore, when dieting, we want to do everything possible to keep these tissues properly maintained and “tuned-up” to the highest possible level so that they can burn as much fat as possible. And (just to hammer the point unmercifully ), I’ll remind you that burning your fat is the only way (short of surgery) that you are ever going to get rid of it. This means it’s critical to handle protein properly when you are dieting.

Dietary protein is made up of 20 different amino acids. When you eat protein, it is broken down during digestion into these constituent amino acids. They are then passed by way of the portal vein to the liver. The liver accurately monitors your need for most of the amino acids and passes the proper amounts of these into the general circulation. It then destroys any unneeded excess by degrading it to urea, which passes out of the body through the kidneys. Basically this means—as in the case of carbohydrate—that although the body can convert protein to fat, it is not an efficient process and only begins to happen after other thresholds are exceeded. Evidence also indicates that, as in the case of carbohydrate, a large excess of protein suppresses fat burning, though not as much as carbohydrate does. Therefore, once again, we need to achieve a balance.

Muscles and other tissues take up the amino acids that are released into general circulation. But muscle and other tissues are not static. They are in a state of nearly constant “renovation”. This means that their proteins are constantly being broken down to amino acids (and other things) which are dumped back into general circulation. About two-thirds of them are taken up again, re-used, and rebuilt into protein somewhere else. The remaining third, composed of substances that can't be re-used, must be replaced by amino acids from food. It is believed that under normal circumstances in a 70 kg (154 lb) person, about 300 grams per day of protein (about ¾ lb) is degraded to it’s various constituents. About 200 grams of these are re-used, leaving about 100 grams to be replaced from food. (These numbers are very approximate however.)

This constant breakdown/rebuild process creates two issues that successful dieters must learn to handle. The first is that the breakdown products that can't be re-used must be replaced by protein from food. If they are not replaced, you will have lost some of the tissue that burns fat. If this loss goes on for a long time, you will lose a lot of the tissue that burns fat. This will make weight-loss much harder and slower—particularly the infamous “last five pounds”.

Additionally, at some point in time various protein-starved organs will begin to be unable to function properly—which can make you sick. Eventually, some of those organs will fail—which can kill you. These are all things that have happened to dieters who didn’t know how to handle protein properly.

The second issue that you will run into is that if your body runs out of the glucose needed by the brain and other tissues, it will begin to make glucose out of some of the amino acids that normally would be re-used by the muscles or organs. This accelerates the breakdown of these active tissues and increases the amount of dietary protein you need to rebuild them. The liver begins to run low on glycogen (the stored form of glucose) about 12 hours after your last meal because it can only store enough glycogen to maintain the brain’s normal level of functioning for about that long.