Proteins are chains of amino acids found in every cell in your body.
As the 'building blocks of life,' proteins are used for repair,
maintenance and new growth of cells, and they make up a major part of
your skin, muscles, organs and glands.
Because proteins in your
body are constantly broken down, you need to consume protein in your
diet that is digested into amino acids and used to replace the protein
your body needs to function.
What are "Complete" and "Incomplete" Proteins?
There
are nine essential amino acids that you must get via your diet, as your
body does not make them on its own. Foods that supply all of the
essential amino acids, like meat, milk, eggs and cheese, used to be
called 'complete' proteins, while those that do not were called
'incomplete' proteins. Complementary proteins referred to two incomplete
proteins that together provided all of the essential amino acids.
These
terms are not widely used to describe foods anymore, however, and the
old adage that you had to eat complementary proteins at the same meal to
count as a complete protein source has been disproven. As long as you
consume all of the essential amino acids from a variety of protein-rich
foods in the same day, you'll be fine.
Most Americans Eat More Protein Than They Need
Nutrient
deficiencies are common in the United States, but protein is not
typically among them. According to the U.S. Centers for Disease Control
and Prevention (CDC):
"... most adults in the United States get
more than enough protein to meet their needs. It's rare for someone who
is healthy and eating a varied diet to not get enough protein."
Generally,
you only need about 10-35 percent of your daily calories to come from
protein. For an adult woman, this amounts to about 46 grams of protein a
day, or 56 grams for men. For most people, two to three servings of
healthful protein sources are enough to fulfill your daily protein
requirements. Examples of protein serving sizes include:
- 1/2 cup of beans
- 3 ounces of meat or fish
- 1 egg
- 2 tablespoons of peanut butter
- 1 ounce of cheese
What Happens if You Eat Too Much Protein?
Since
your body can only use a certain amount of protein each day, if you
regularly consume more than your body needs, the extra protein calories
will be stored as fat, which can lead to weight gain (each gram of
protein has four calories). There are other potentially harmful effects
as well, including:
