Protein & Amino Acids 101
Why, How Much, and How to Get Protein in Your Diet
Why People Need Protein
Proteins are everywhere in the body – from the hemoglobin in the blood, to the bones, skin, hair, nails, and, of course, muscle tissue. In fact, 75% of our body’s non-water weight is from protein.
Proteins are needed to build new cells, maintain tissues and organs, and make other proteins (particularly enzymes, which help chemical processes occur in our bodies). Without enough protein, a person can develop a wide range of health problems, including anemia, fluid retention (the cause of bloated bellies of starving children), hair loss, muscle wasting and a painful type of arthritis called gout.
How Much Protein?
There are over ten thousand proteins, but each one is made from long chains of just 20 amino acids, the building blocks of protein. Our bodies can make 11 of these amino acids. The other nine, called essential amino acids, must be obtained from food.
Considering how important protein is, it would seem like we need a ton of it. In reality, the average adult needs a protein intake of 50-65 grams, or the amount in one good-size hamburger. Even athletes and pregnant or nursing women, who need slightly more protein, can easily get it from a regular diet.
It is possible to have too much of a good thing. Excess protein (from very high protein diets, for instance) can cause the body to leech calcium from bones, weakening them and increasing the risk of osteoperosis. Also, people who have liver or kidney disease can have trouble getting rid of the nitrogen waste created by too much protein. For these people, a low protein diet can help.
Sources of Protein
The food we eat provides two main types of protein:
Complete protein has abundant amounts of the nine essential amino acids. Eggs, whole milk, chicken, fish, beef and soy are all sources of complete protein. Just one serving of chicken or beef (the size of a deck of cards) meets half of an adult’s daily protein needs!
Incomplete proteins contain some, but not all, the amino acids our bodies need. Examples of incomplete proteins include beans (3/4 complete), rice (2/3 complete), and whole wheat (1/2 complete). Most foods, including dairy products, vegetables, and grains, contain at least some protein.
The good news is that a person gets all the essential amino acids by pairing up sources of incomplete protein. Here are some common ways people pair up so-called complementary goods to obtain every type of essential amino acid:
- Legume + whole grain = rice and beans
- Legume + dairy product = chili and cheese
- Whole grain + dairy product = pasta with cheese
- Dairy product + nuts/seeds = yogurt with sunflower seeds
However you get your protein, be aware of what other things come along with it. Many protein-rich foods (like red meat) are also high in saturated fats and cholesterol, while others (like fish and nuts) have added health benefits like omega-3 fatty acids or antioxidants.
