What Is a Complete Protein?

Protein is an essential macronutrient that we need to consume every day in our diet. Depending on your size, age, weight, and activity levels, your protein needs will differ. However, you should aim to get at least 25% of your daily calories from protein.

Protein is vital for muscle maintenance and growth. It’s also a key component of hair, skin, nails, and connective tissue. When you eat protein-containing foods, they are broken down by the digestive system into their constituent amino acids. These amino acids are then absorbed into the bloodstream and used to assimilate new proteins, cells, and tissues in the body.

There are two different kinds of proteins - complete and incomplete. Let’s break down what each type of protein is and what it means when it comes to your dietary protein intake.

What Are Complete and Incomplete Proteins?

Complete proteins refer to proteins that contain all of the nine essential amino acids. On the other hand, incomplete proteins don’t contain all of the nine essential amino acids but can contain a combination of some of them.

Proteins consist of 20 amino acids in total, 11 of which the body can make itself (non-essential amino acids) and the other 9 of which it is unable to synthesize (essential amino acids). The essential amino acids include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Because the body cannot synthesize them, we need to consume these nine amino acids so our bodies can create new proteins and cells.

Protein for Vegetarians and Vegans

Every animal based product has complete proteins. However, no plant based protein sources are complete.

If you’re a vegan or vegetarian, it’s important to know which protein sources to eat in your diet, so you get enough of every essential amino acid.

The following foods contain almost complete proteins:

• Quinoa
• Buckwheat
• Tofu
• Tempeh
• Lentils
• Chickpeas
• Beans
• Hemp seeds
• Chia seeds
• Ezekiel bread

Combining multiple plant-based protein sources will ensure you are taking in every amino acid that your body needs. For example, you could make chili using lentils, chickpeas, and beans to get a variety of amino acids, or make a stir fry dish that combines tofu and tempeh.