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5 Key Functions of Protein

5 Key Functions of ProteinDo you ever wonder what protein does for your body (and where to get it)?

You’ve likely heard about how important protein is, but do you know why?

Protein is one of the 3 macronutrients (the other 2 being carbs and fat). It is a major component that makes up many foods and is made up of individual amino acids that form together to create long chains (think of a ladder or long necklace). There are a total of 20 amino acids that make up all proteins, with 9 of them considered “essential” and the other 11 being nonessential. Both are important, but the difference is that our bodies can make the nonessential amino acids, while they cannot make the essential ones, so those must come from our diets.

Protein plays a number of crucial roles in our bodies and is vital to health for many reasons. Without protein our bodies ability to grow, repair and build muscle and tissues and organs, and do basic bodily functions like produce hormones as well as protect us from illness would be severely compromised (more on these in a bit). So we benefit greatly from protein!

Read on for more information about what protein does for us…

5 key functions of protein in the body

  1. Supports our immune system. The amino acids that protein provides serve as fuel for the immune system and help build antibodies which fight off infection and other foreign invaders. Not getting enough protein is associated with weakened immunity.
  2. Crucial for growth and maintenance of tissues. We need protein to help make and repair cells, which form everything from muscles to vital organs and tissues like our skin, hair, nails, cartilage, and more. Our protein stores are constantly changing, and needs are increased during times of illness, injury, and growth such as during pregnancy.
  3. Produces hormones & enzymes. Many proteins are hormones which communicate between different systems and allow the body to function properly. For example, thyroid stimulating hormone (TSH) is a protein that communicates with our thyroid glands to help it operate. Protein also makes up many enzymes, which produce thousands of biochemical reactions including things like digestion and blood clotting.
  4. Provides structure & transports nutrients. Protein makes up the framework of our cells. A great example of this is collagen, which is the most abundant protein in the body and provides structure to bones, tendons, ligaments, skin, and cartilage. Examples of transport proteins are hemoglobin, which transports oxygen in our blood, and ferritin, which transports and stores iron, both of which are vital to life!
  5. Serves as an energy source. Protein can be used for energy in the body, though this is a secondary function as the body prefers to use carbohydrates first for energy and reserves protein for other, more important functions. Protein provides 4 calories per gram and will be used for energy when carbohydrate stores are low such as in a state of fasting or starvation.

So now that you understand some of protein’s major roles, let’s talk about where we get it in our diets…

Food Sources of Protein: Animal versus Plant

Protein from animals is considered “complete protein” because it contains all 9 essential amino acids.

  • Good animal protein sources include: eggs, greek or icelandic yogurt, minimally processed lean poultry and meats, as well as whey protein powders as needed.

As for plant proteins, these are considered “incomplete proteins” because they lack one or more of the essential amino acids. This doesn’t mean plant-based proteins are worse, though, and it is still very possible to meet all essential protein requirements on a plant-based diet. You may have heard that you need to pair certain plant based proteins together to create a “complete protein”. While there is some truth to this, it doesn’t need to be a major concern as consuming a variety of plant proteins each day will likely allow you to get all of the amino acids you need.

  • Good plant-based protein sources include: beans, lentils, nuts, seeds, nut butters, organic soy products like tofu, tempeh, and edamame, and plant-based protein powders made with clean ingredients (pea, hemp, and brown rice protein blends are popular).

If you’re wondering about serving sizes for protein, first know that we always recommend listening to your body first to determine how much to eat. 1 oz is equal to about 7 grams of protein, and how much you need per day will depend on your body size, health situation, and activity levels.

Here are some basic guidelines for a typical recommended serving for common protein foods:

  • Meat, fish & poultry: about 4 oz which is the size of a deck of cards or the palm of your hand
  • Eggs: 2 medium sized
  • Beans: ½ cup or the size of a computer mouse
  • Cheese: 1 oz or about the size of 4 dice or the length of your index finger
  • Nuts: ¼ cup or about one level handful

High protein recipes

If you’re looking to include more protein into your diet, here are some of our favorite protein rich recipes to help you do just that (there are both animal and plant based options here):

Questions? Just contact us and ask!

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