Protein is essential for growth and development. It
provides the body with energy, and is needed for the manufacture of hormones, antibodies,
enzymes, and tissues. It also helps maintain the proper acid-alkali balance in the body.
When protein is consumed, the body breaks it down into
amino acids, the building blocks of all proteins. Some of the amino acids are designated nonessential.
This does not mean that they are unnecessary, but rather that they do not have to come
from the diet because they can be synthesized by the body from other amino acids. Other
amino acids are considered essential, meaning that the body cannot synthesize them,
and therefore must obtain them from the diet.
Whenever the body makes a protein-when it builds
muscle, for instance-it needs a variety of amino acids for the protein-making process.
These amino acids may come from dietary protein or from the body's own pool of amino
acids. If a shortage of amino acids becomes chronic, which can occur if the diet is
deficient in essential amino acids, the building of protein in the body stops, and the
Because of the importance of consuming proteins that
provide all of the necessary amino acids, dietary proteins are considered to belong to two
different groups, depending on the amino acids they provide. Complete
which constitute the first group, contain ample amounts of all of the essential amino
acids. These proteins are found in meat, fish, poultry, cheese, eggs, and milk. Incomplete
proteins, which constitute the second group, contain only some of the essential amino
acids. These proteins are found in a variety of foods, including grains, legumes, and
leafy green vegetables.
Although it is important to consume the full range of amino
acids, both essential and nonessential, it is not necessary to get them from meat, fish,
poultry, and other complete-protein foods. In fact, because of their high fat content-as
well as the use of antibiotics and other chemicals in the raising of poultry and
cattle-most of those foods should be eaten in moderation. Fortunately, the dietary
strategy called mutual supplementation enables you to combine partial-protein foods
to make complementary protein-proteins that supply adequate amounts of all the
essential amino acids. For instance, although beans and brown rice are both quite rich in
protein, each lacks one or more of the necessary amino acids. However, when you combine
beans and brown rice with each other, or when you combine either one with any of a number
of protein-rich foods, you form a complete protein that is a high-quality substitute for
meat. To make a complete protein, combine beans with any one of the following:
- Brown rice.
Or combine brown rice with any one of the following:
All soybean products, such as tofu and soymilk, are
complete proteins. They contain the essential amino acids plus several other nutrients.
Available in health food stores, tofu, soy oil, soy flour, soy-based meat substitutes, soy
cheese, and many other soy products are healthful ways to complement the meatless diet.
Yogurt is the only animal-derived complete-protein source
recommended for frequent use in the diet. Made from milk that is curdled by bacteria,
yogurt contains Lactobacillus acidophilus and other "friendly"
bacteria needed for the digestion of foods and the prevention of many disorders, including
candidiasis. Yogurt also contains vitamins A and D, and many of the B-complex vitamins.
Do not buy the sweetened, flavored yogurts that are sold in
supermarkets. These products contain added sugar and, often, preservatives. Instead,
either purchase fresh unsweetened yogurt from a health food store or make the yogurt
yourself, and sweeten it with fruit juices and other wholesome ingredients.
Next Topic: Fats