Protein is a nutrient that is essential for life.
Proteins make up a large part of our muscles, organs and glands, and
they help build and repair body tissue. Growth and development in
children and adolescents is largely dependent upon proper protein
intake. Proteins also strengthen the immune system, manufacture hormones
and antibodies and preserve the acid-alkali balance in the body.
Like carbohydrates, one gram of protein yields four calories. The
following calculation demonstrates the number of protein grams consumed
in a diet comprised of 30% protein:
If an adult consumes 1,800 calories per day, the calculation would
be:
1,800 (calories) x 0.3 (30%) divided by 4 (calories per gram) = 135
grams of protein
Types of protein
The building blocks that make up proteins are called amino acids. There
are 22 amino acids in total; nine are classified as essential, meaning
the body cannot synthesize them, so they must come from the diet. The
remaining 13 are non-essential, meaning the body can synthesize them so
they do not have to be derived from food sources. Proteins are divided
into two categories:
- Complete proteins
- Incomplete proteins
Complete proteins contain all the essential amino acids. They are
found in meat and other animal products such as beef, lamb, pork,
poultry, fish, eggs, milk and milk products. Incomplete proteins do not
contain all the essential amino acids. Examples of incomplete proteins
are grains, legumes, beans, nuts, fruits and vegetables. Incomplete
proteins can be combined to make complete proteins, such as:
- Rice and beans
- Cereal and milk
- Beans and corn
- Bread and cheese
Protein-rich foods
A nutritionally balanced diet with adequate amounts of protein is
essential for optimum health. It is important to include a variety of
lean proteins into your diet such as cold-water fish, poultry without
the skin, lean meat, turkey, eggs, lowfat dairy products and dried
beans, lentils and legumes. To learn more about proteins and how to
maintain hormonal balance in your diet, please visit the 40:30:30 Method of Eating. |