Whether from plants or animals, protein plays a huge role in how we live and function. The blood that pumps through your veins is made of protein. The lattice work that gives your bones structure is made of protein. When you smile, lift a grocery bag, or blink your eyes, it is protein that makes it possible for these muscles to contract! Our hormones also require protein, making this nutrient essential for mood, sexual function, blood sugar regulation, and brain function.
The Building Blocks of Protein
When you eat food that contains protein, the digestive juices in your stomach and intestines work to break it down into basic units called amino acids. The amino acids can then be reused to make the protein your body needs to maintain muscles, bones, blood, and body organs.
Scientists have found many different amino acids in protein, 20 of which are very important to our health. Of those 20 amino acids, your body can make 11 without you ever knowing it. Your body can't make the other nine amino acids, so they must be consumed from animal and plant sources. They are called essential amino acids because it's essential that you get them from the food you eat. Some proteins are called conditionally essential, and may be essential during times of injury, illness, or poor digestion.
To learn more about the amino acids, click here.
Recommended Daily Allowance (RDA)
46 grams per day for women over 19 years of age
56 grams per day for men over 19 years of age
Sources of Protein
Most animal protein, such as meat, fish, poultry and eggs, provide what is called "complete protein," meaning that they contain all of the essential amino acids. Organic eggs are one of the most complete protein sources, and contain every essential amino acid the body needs.
Healthy sources of animal protein include beef, buffalo, chicken, duck, pork, game meat, seafood, eggs, and dairy.
3 oz. filet of salmon— 22 grams
3 oz. chicken breast— 16 grams
3 oz. lean beef— 22 grams
1 large egg— 6 grams
1 cup whole milk— 8 grams
Vegetable sources are usually lower in protein and are often missing certain essential amino acids. For example, rice is low in isoleucine and lysine. This has caused some concern about vegetarians not getting adequate amounts of protein in their diet.
There have been many heated arguments about the advantages and disadvantages of a vegetarian diet by the doctors, patients, and parents of children who have adopted a vegan or vegetarian lifestyle. Both sides have equal merit. The good news is that no matter what your belief system, it is not as difficult to get all the essential amino acids as we once thought. Vegetarians can get the array of amino acids that the body needs as long as they make sure to vary their plant protein sources and eat a combination of different types throughout the day. Rice and beans may be merely a camping go-to for some of us, but it is often a diet staple for those with limited dietary options.
Healthy sources of plant protein include legumes, grains, nuts and seeds.
1 oz. almonds— 6 grams
1 oz. pumpkin seeds— 5 grams
1/2 cup raw oats— 13 grams
1 cup cooked quinoa— 8 grams
1 cup cooked lentils— 18 grams
Next time you're at the grocery store and choosing a protein to have for dinner, remember that quality is everything. Especially in regards to meat! Take a look at the next section, Healthy Protein Decisions to help you make the best choices.