Proteins are often referred to as the basic building blocks of the human body because they are used to build and repair body tissues, muscles and organs, produce hormones and digestive enzymes, and provide immune functioning. Proteins are giant molecules constructed by linking large number of amino acids. There are a total of 22 amino acids. Much like letters in the alphabet can be combined to form different words, amino acids can be linked together in varying sequences to form a large variety of proteins.
Your body needs protein to:
-Grow. Sufficient protein is needed to grow during childhood, teen years, and for women during pregnancy.
-Repair tissues in the body. Protein repairs muscle tissue, forms scars, and replaces worn out cells.
-Produce new blood cells. Red blood cells (cells that carry oxygen throughout the body) last about 3-4 months. Protein is needed to make new ones in the bone marrow.
-Keep your immune system strong. Proteins are needed to form antibodies, which fight off diseases and viruses.
-Manufacture hormones and enzymes. Hormones are messenger molecules that regulate many body processes. Enzymes help chemical reactions occur. Both of these important substances are made up of amino acids.
-Maintain acid base balance. Proteins in the blood act as a buffer preventing dangerous conditions of too much acid (acidosis) or too much base (alkalosis).
-Keeps hair, nails, bones, skin, and teeth strong.
-Maintain fluid and electrolyte balance. Proteins maintain proper balance between fluids and electrolytes (sodium and potassium), which are critical for nerve and muscle functioning.
Eating protein also helps keep you full in between meals and snacks.
Protein is found in a wide variety of animal and plant foods. Animal-based protein foods include seafood, meat, poultry, eggs, milk, and cheese. Plant sources of protein include legumes (black beans, garbanzo beans, kidney beans, lima beans, snap peas), grains, nuts, seeds, and soy products. For young children (ages 1-3 years), 5-20% of the calories needed each day should come from protein. For older children and adolescents (ages 4-18 years), 10-30% of the calories needed each day should come from protein. For adults (ages 19 years and older), 10-35% of the calories needed each day should come from protein.
It is possible for the human body to make some of the amino acids that our body requires and these are called nonessential amino acids (meaning, we do not necessarily need to eat them). The other 9 amino acids are called essential amino acids. Our body is not able to make its own essential amino acids and we therefore must eat them to stay healthy.
The Nonessential amino acids are:
The essential amino acids are:
A food is referred to as a complete protein if it contains all of the essential amino acids. If a food is missing just one essential amino acid, it is not considered a complete protein. Without a complete protein, optimal growth (and therefore health) cannot be reached. Animal foods and soy are the only foods that provide complete proteins. Legumes, nuts, seeds, and grains do not provide complete proteins. However, pairing legumes, nuts, or seeds with grains can form a complete protein. For example, you can’t get all of the essential amino acids you need from peanut butter alone, but if you have peanut butter sandwich, you’ve got a complete protein. Likewise, red beans won’t give you everything you need, but a dish of red beans and rice will. Focus on getting a variety of protein sources in throughout the day. It is not necessary for you to consume all of the essential amino acids in every meal. Instead, focus on consuming them throughout the day as your body will grab what it needs from each meal.