Protein seems to be an often debated topic – especially when you mention you’re vegan. Let’s have a look at the meaning of complete proteins, if plant-based proteins are actually incomplete, plant-based complete protein sources and what that means for the food we eat.
What does complete protein source mean?
To understand what a complete protein source is, we need to take a closer look at amino acids. Amino acids are the building blocks of protein. The protein we get from our food is made up of different amino acids.
Understanding amino acids
Our body needs amino acids to build and maintain protein structures (such as muscles). So when we eat tofu or beans, our body breaks down the protein into individual amino acids and uses these amino acids to build muscles and other tissues.
Our body can actually make some amino acids by itself – but not all of them. The ones we cannot make ourselves are called essential amino acids. There are 9 essential amino acids. They are essential because we need to get them from food.
Amino acid profiles
To make protein structures like muscle, our body needs all of the essential amino acids in a specific ratio. You can think of it as a construction manual which tells you exactly how many parts of each component you need. If there’s not enough of one essential amino acid (or it is missing all together), our body can not function properly.
Every protein source has a different amino acid profile. Some protein sources have a lot of methionine but only a little bit of lysine. Others have a lot of lysine but only little methionine. And some have just the right amount of each amino acid as it is written in our protein construction manual. These are what we call complete protein sources.
Animal protein sources are complete protein sources – and that’s actually no surprise. Animals use the same amino acids to build protein structures and tissue like we do – we are both mammals.
Are plant-based protein sources incomplete?
Plant-based protein sources are often described as incomplete. This is a bit misleading because it suggests that plant-based protein sources are missing essential amino acids.
Actually, plant-based proteins are not missing any amino acids! In fact, plant-based protein sources do have all essential amino acids – just not in the right ratio. Thinking back to the construction manual analogy, a plant-based protein source might only have 2 screws then the manual calls for 8 screws. Plant-based protein sources are not really “incomplete”, they might just not have the right balance/ratio of amino acids as our body would need them.
If you want to learn more, check out this article.
Are there plant-based complete protein sources?
Yes, there are plant-based protein sources that have an amino acid profile like our body needs. Here is a list of plant-based complete protein sources:
- soy beans and products made out of soy beans like tofu, tempeh, soy milk
- hemp seeds
- chia seeds
What are complementary proteins?
As we have discussed, every protein source has a specific amino acid profile. If you combine two different protein sources, they can complement each other and can create an amino acid profile that matches our construction manual. The two protein sources are called complementary proteins.
Combining vegan protein sources
We don’t need to consume a complete protein source every time. We can also combine different protein sources that complement each other. Some good complementary protein combinations are:
- whole wheat bread and hummus
- black bean chili and rice
- tofu curry and rice
- whole wheat pasta and lentil bolognese sauce
- whole wheat tortilla and tofu scramble
- chickpeas and tahini (= hummus)
- lentil soup with bread
As you can see, this is not complicated at all. Most of these combinations are actually combinations we would eat anyways because we’re used to them.
Also, we don’t need to eat complementary proteins together at every meal. Our body is able to store amino acids throughout the day. So as long as throughout the day, we get a variety of proteins will all the essential amino acids, then we’re fine.
Is vegan protein powder complete?
It depends what protein source the protein powder is made of. If it is made of a complete protein source like soy, then yes, that vegan protein powder is also a complete protein source.
Many protein powders consist of a combination of protein sources like hemp, pea, soy or brown rice. Through these combinations, two individually “incomplete” protein sources can be combined to form a complete protein powder.
How to make sure your vegan diet contains all essential amino acids
If you are worried about getting all of the essential amino acids on a vegan diet, here are some actionable tips:
- make sure you don’t rely on one protein source only
- eat a variety of different protein sources throughout the day
- make sure to include a serving of legumes and a serving of grains every day
- consume a variety of nuts, seeds and legumes
- eat enough (one reason why people don’t get enough protein is because they simply don’t consume enough calories)