page 118 Calories Don't Count Dr Herman Taller MD

Protein is a combination of chemical substances called amino acids. While protein, like a carbohydrate, contains molecules of carbon, hydrogen, and oxygen, protein also contains nitrogen. The element nitrogen, which is essential to life, is not present in carbohydrates.
the body breaks down protein you consume through food into carboihydrates and into notrogen. This protein breakdown, as you remember, is one source of carbohydrates, and the typical American diet is so rich in protein that many of us could probably subsist without eating any carbohydrates at all. (I am not recommending that you try. I am only pointing out that whereas you could not live without protein, you could live, perhaps quite comfortably , without eating any sugars or starches.)

If the body turns protein into carbohydrate, you may wonder, won't it run into the problem of pyruvic acid? Won't obese people, in whom pyruvic acid turns to fat, get into as much weight trouble eating protein as they do eating carbohydrates? The answer, fortunately, is no. You can eat too much protein, just as you can eat too much carbohydrate, but practically you are unlikely to. Your appetite is far better at regulating your protein intake than it is at regulating your carbohydrate intake. The problem of your eating so much protein that the body, in breaking down the protein, becomes oversupplied with carbohydrates is pretty much nonexistent.

Physiologists estimate that the body can use one gram of protein for every kilogram of bodyweight. Translating this into mores meaningful terms, a 150-pounde can handle about 70 proteins grams a day. Two normal slices of good lean beef supply only 28 grams of protein. In practice a 150-pounder is not likely to exceed his 70 grams very often or by very much.