Protein is one of our bodyís major building blocks. Itís a primary component of our organs, muscles, tendons, ligaments, and glands. In fact, the function of every living cell depends on protein.

The word protein comes from the Greek word proteios meaning ìof prime importance.î Itís so important that protein is often referred to as the quintessential nutrient. Protein is formed by synthesizing amino acids. Our bodies need 22 amino acids to synthesize proteins. These amino acids can be divided into two groups. The first is called ìessential,î because these amino acids can not be manufactured by our bodies. The non-essential amino acids can.

Proteins can also be broken down into two categories: complete proteins, which contain all essential amino acids, and incomplete proteins, which do not. Complete proteins come from animal sources like poultry, meat, fish, dairy products, and eggs, while incomplete proteins come from plant sources like vegetables, fruits and whole grains.

In addition to helping form and repair major tissues within our bodies, proteins are crucial in the manufacturing of enzymes and some hormones. For example, insulin is a protein that helps regulate blood sugars.

Proteins are also a critical component of our immune system. Proteins are vital to produce antibodies, which are gamma globulin proteins our immune system uses to identify and neutralize foreign objects such as bacteria.

Some proteins have the specific task of transporting nutrients and other needed molecules throughout our bodies. Proteins play an essential role in maintaining our bodyís fluid balance

Since proteins are too large to pass through the semipermeable membranes of blood vessels, they create osmotic pressure, which shifts water toward them. This draws fluid away from tissues, back into the bloodstream.

Even though we must obtain protein from our diets, I donít recommend over consumption. First of all, the average person can only absorb about 25-30 grams at a time. Whatís left over, the body doesnít store, it excretes. Thatís not the biggest problem though. Ridding your body of excess protein puts a heavy strain on your kidneys. In fact, back in the 1960s and 70s, some actually died from those concentrated liquid protein diets.

I recommend that oneís diet contain no more than 30 percent calories from protein. The RDA for protein for healthy adults is 0.8 grams for each kilogram (2.2 pounds) ideal body weight. ìIdealî body weight should be used here, rather than actual body weight, because body fat contains very little protein.

I recommend your dietary protein come from both plant and animal sources. Some folks try ìprotein combining.î The theory is that if you eat two complimentary foods, each missing different amino acids, you get a complete protein. Thatís only half true, because there is a difference between a complete protein and a high quality protein. What constitutes a high quality protein for human consumption is not just all amino acids present, but the amount of certain amino acids, and plant based proteins in and of themselves donít provide this.

Also, for those of you watching your weight, donít fall into what I call the ìprotein trap.î Many dieters would never think about eating a six-ounce bag of potato chips (thatís a family sized bag, by the way) in one sitting, but would think nothing of eating a nine-ounce sirloin steak. Guess what? Protein and carbohydrates have the same number of calories (four) per gram.

Diet or exercise question? Email me at dwcrocker77@gmail.com or visit fitnessforyourlife.org. David Crocker of Landrum has been a nutritionist and  master personal trainer for 28 years. He served as strength director of the Spartanburg Y.M.C.A., head strength coach for the USC-Spartanburg baseball team, the S.C. state champion girls gymnastic team, and the Converse college equestrian team. He served as a water safety consultant for the United States Marine Corps, lead trainer to L.H. Fields modeling agency, and taught four semesters at USC-Union. David was also a regular guest of the Pam Stone radio show.