Proteins in Nutrition

Proteins in Nutrition

Proteins are very large molecules made of amino acids, of which there

are twenty. Eight of these amino acids are "essential," meaning that

they cannot be synthesized in the body even though they are necessary

for life. Essential amino acids must be consumed from sources outside

the body.

Early in the twentieth century, studies of rats revealed that this

rodent grows better using animal sources of protein. Knowing nothing

of humans, which are harder to study because they live so much longer,

grow to adulthood so much slower, and metabolize food so much slower,

nutritional scientists applied what they had learned about rats to

humans. The conclusion was that animal sources of protein were

superior to plant sources for human nutrition because of the higher

concentration of protein.

In the early 1950s, definitive studies were conducted on human beings,

and the eight essential amino acids were identified. Both animal and

plant sources of amino acids provide an abundance of the essential

amino acids. As it turns out, the amino acid needs of human beings can

be met better by some plant sources, such as soy, because plant

protein comes without the heavy load of fat present in meat, milk and

eggs. Milk is said to be a good source of protein. Perhaps so, but the

problems associated with pasteurized milk and milk products make it a

less than desirable source.

At first glance, it may seem that animal sources of protein would be

superior because of the higher concentration of protein. However, as

it turns out, the body cannot distinguish the source of protein, or

the concentration, only the total amount. The pro...

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The high purine content of a high-protein diet leads to gout and

kidney stones in some people, as purine breaks down to uric acid,

which crystallizes in the kidneys and joints. A diet with a sensible

amount of protein is highly beneficial for these conditions. This

sensible diet is achieved through vegetables high in fiber

(nondigestible forms of complex carbs) with a sensible amount of

protein and whatever fat comes with that protein.

To make this simple, all you need to remember is to consume, three

times each day, about the amount of protein source which could be held

in the palm of your hand - about the size of a chicken breast -

constituting about thirty percent of your calories. With that, have

whatever fat comes associated with that protein. Add high-fiber

vegetables, the equivalent of three handfuls.