2. Why We Need Protein
Protein is needed by the body for only two reasons: I) growth and 2) tissue repair and replacement. Protein is not necessary for muscular energy, increased activity or as a source of fuel.
2.1 Growth and Tissue Repair
Proteins support normal growth and maintenance of the body tissues.
Perhaps the role of protein in growth is best exemplified in the development of babies and newborn animals. A relatively high amount of protein is found in the milk of lactating mothers to insure healthy tissue growth in the young child. The protein needs are highest when growth is the fastest. For instance, compare the protein content in mother’s milk after the first six months of birth:
|Time After Birth||Percent Protein|
|From the 8th to 11th day||2.38|
|From the 20th to 40th day||1.79|
|From the 70th to 120th day||1.49|
|At the 170th day and later||1.07|
Notice that the highest protein contents occur during the earliest stages of growth to allow for rapid development of the baby. As the growth of the child begins to slow, so does the protein content found in the mother’s milk. It is also interesting to note that the percentage of protein found in mother’s milk is approximately the same as the protein content of most fruits and vegetables. For example, grapes have a 1.3% protein content, raspberries 1.5%, dates 2.2% and so on.
We can also find a relationship between the protein content of the milk of lactating animals and the growth rate of their young by studying the following chart:
|Number of Days for Newborn to Double Its Weight||Average Protein Percentage In Mother’s Milk|
The highest need for protein in the diet occurs for most animals during the above periods when the newborn is doubling its birth weight. It is important that we realize the protein content in mother’s milk, the optimum food nature has provided for rapid growth of the young, is far below the usual foods that are recommended because of their high protein content (such as meat, nuts, legumes, grains, etc.). Protein is indeed important for growth, but we might well question the alleged necessity for concentrated, high-protein foods.
2.3 Tissue Repair and Replacement
The second role of protein is in the repair of tissues or replacement of worn-out cells. After an organism reaches its full growth (usually between 18 and 22 years for humans), protein is needed only to supply the loss incidental to tissue waste. Cell degeneration and waste occur primarily because of toxicity in the body. If we adopt a lifestyle and diet that introduce a minimal amount of toxins into the body, then tissue waste will decrease significantly. As a result, actual protein needs will also diminish.
After an individual reaches adulthood, the only protein needs are for the repair and replacement of tissues that have deteriorated, due largely to body toxicity.
2.4 Not As A Fuel Source
Protein is not used directly as fuel for the body or for muscular activity. In muscular work, excretion of nitrogen as a result of protein usage increases only very slightly. Instead, it is the excretion of carbonic acid and absorption of oxygen that increase. These changes indicate that an expenditure of energy is derived mainly from non-nitrogenous foods (such as carbohydrates and fats) and not, from protein.
It is true that the body can use protein to generate fuel for physical activity, but it does so by breaking the protein down into a carbohydrate form. Protein is used as fuel only when there is either an excess of proteins or a lack of carbohydrates. When this occurs, the body splits off the nitrogenous matter from the protein molecule and uses the remaining carbon contents to produce fuel. This process not only involves a net loss of energy, but it also places an unnecessary strain on the liver, kidneys and other organs to eliminate the unusable nitrogenous wastes.
It is for this reason that the popular high-protein, low-carbohydrate diets result in weight loss and also why they are dangerous. Since the body has to expend so much energy in converting the excess protein into the needed carbohydrates for fuel, a net loss occurs in the body and the dieter loses weight. At the same time, he also places a heavy burden on his kidneys to eliminate all the uric acid generated by this protein breakdown and simultaneously overworks an already exhausted liver.
If more physical activity is anticipated, it is only necessary to increase the carbohydrate intake of the diet. Proteins are very poor in fuel-efficiency and do not aid directly or efficiently in muscular activity.
- 1. Introduction
- 2. Why We Need Protein
- 3. How Much Protein Do We Need?
- 4. What Are Proteins?
- 5. The Importance Of Amino Acids
- 6. “Complete Proteins”
- 7. Protein And The Optimum (Life Science) Diet
- 8. Questions & Answers
- Article #1: The Question Of Proteins By Arnold DeVries
- Article #2: Protein By Ralph Cinque, D.C.
- Article #3: The Superiority Of Plant Foods By Ralph Cinque, D.C.
- Article #4: The Question Of Protein By Dr. Ralph Bircher Benner