Vegan Complete Protein: (Combinations + Sources)

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Whether or not a protein source is “complete” isn’t a big deal in most cases.

Your body keeps a pool of free essential amino acids, so as long as you vary your protein sources throughout the day, you’ll get enough of each amino acid.

But if you want to know which vegan foods have amino acid profiles that complement each other, I’ve got you covered here.

Vegan Food Sources That Are Complete Proteins

There are two parts for a food to qualify as a complete protein:

  • Having a sufficient quantity of each essential amino acid
  • Having a minimum percentage of each essential amino acid

Most vegan protein sources lack one or the other.

If we look at the best vegan sources of protein, there are a few protein rich foods near the top of the list that are complete:

  • Soy (tempeh, tofu) – Even though soybeans themselves aren’t a complete source of protein, the process that results in tofu does form a complete protein by most definitions.
  • Seeds (certain ones like hemp, pumpkin) – Not all seeds are complete protein, but most are close at a minimum, and are also great sources of healthy fats. Both hemp seeds and chia seeds are complete sources of protein.
  • Nutritional yeast – By most definitions, nutritional yeast is a complete protein. It’s a great source of protein to add on top of a variety of meals.

Referring back to the best overall plant-based sources of protein, there are also certain types of food that are near the top of the list that aren’t complete proteins:

  • Vital wheat gluten – The amino acid profile of seitan will vary depending on the recipe used, but it’s usually relatively low in lysine.
  • Nuts – Nuts are typically low in lysine and methionine, and don’t have a complete profile of essential amino acids. Peanuts (technically legumes) are the closest.
  • Beans (Legumes) – Great sources of plant protein, but all beans are low in methionine.

Let’s look at these in a bit more depth.

Incomplete Sources of Vegan Protein

I’ve written a detailed post outlining the essential amino acid profiles of beans before.

The picture below shows how many 1 cup servings of each bean is needed to reach the RDA of each essential amino acid.

beans amino acids servings per day

You can see that it’s pretty easy to get all essential amino acids except for methionine.

I wrote a similar post for the essential amino acid profiles of nuts, and made a similar chart, shown below.

servings to reach rda of amino acids in nuts

Once again, methionine is an issue for all nuts except brazil nuts.

Nuts are also relatively low in lysine, except for peanuts, cashews, and pistachio nuts.

SUMMARY

The best sources of vegan protein that are incomplete typically lack lysine and methionine.

Best Protein Pairings for Beans and Nuts

Ideally, we can find some vegan foods that are high in both lysine and methionine. These would then form complete protein meals once combined with beans or nuts.

The best vegan sources of methionine include:

  • Whole grains (including vital wheat gluten) – Oats, buckwheat, flour, etc.
  • Seeds (most types)

And for the best vegan sources of lysine:

  • Leafy greens – Spinach, swiss chard
  • Whole grains – Oats, buckwheat, etc.
  • Seeds

There aren’t many good sources for lysine, and beans and nuts are actually among them just because they still have a relatively high amount of protein overall (but a relatively small amount of lysine).

SUMMARY

We can see that both whole grains and seeds can pair with incomplete proteins like beans or nuts to form meals with a complete protein amino acid profile.

Summary: Do You Need to Pair Plant-Based Protein Sources?

Overall, you typically don’t need to consciously worry about combining protein sources unless your protein intake is almost entirely from one food.

Regardless, seeds, tofu, and nutritional yeast are good plant proteins with all the amino acids that you’ll need.

Gluten, beans, and nuts have mostly complete profiles of the nine essential amino acids, but lack in either lysine or methionine. These can be paired with seeds, whole grains, or leafy greens to round out a meal. Here are a few examples of such pairings:

  • Toast with nut butter
  • Oatmeal with nuts and seeds
  • Salads with legumes
  • Spinach in chickpea curry or chili
  • Lentil and vegetable soup

You can find plenty of meal ideas in my collection of over 150 high protein vegan recipes if you need inspiration.

About the author

Dale Cudmore

Your friendly neighborhood vegan from Toronto. I've spent over 6 years as a freelance nutrition writer and researcher. During this time, I've tested over 50 vegan protein powders, and over 100 other types of vegan supplements.