Essential Amino Acid Profiles for All Common Beans

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Beans are an awesome source of nutrition whether you’re vegan or not.

But…they aren’t perfect. You shouldn’t rely on them for all your protein needs, because as we’ll see, beans are deficient in certain types of amino acids.

Using detailed data from the USDA’s food database, I extracted the amount of each essential amino acid in the most common beans.

First, we’ll look at them altogether to spot some trends, then break down each bean one at a time.

The Number of Servings Required to Meet Your RDA

This section alone will probably contain the answers you were most looking for when you stumbled across this post.

The RDA for all amino acids is in terms of mg per kg of bodyweight. So it’s different for everyone.

By using a 70 kg (154 lb) person as an example, I calculated the number of servings for each type of bean to meet the RDA of each essential amino acid. All servings are 1 cup of cooked beans.

Click the image below to open up the full-size version if it’s hard to see:

beans amino acid profiles summary chart

I applied some basic conditional formatting to the results where green means that it requires few servings, red requires many servings.

The biggest trends that we see are:

  1. All beans have a lot of tryptophan, threonine, and histidine.
  2. All beans have low amounts of methionine.
  3. Many beans (but not all) have low amounts of leucine and valine.
  4. Fava beans have a low amount of protein overall, and a low amount of all amino acids.

So what now?

Regardless of which beans you eat often, you need to find a better source of methionine.

I’ve compiled the top 30 vegan sources of methionine in another post.

But leucine and valine depend heavily on which types of beans you eat. You should be able to see from the image if the beans you eat are low in those two and whether or need alternative sources.

If you do, here are:

If you can’t tell from the image alone, scroll down to each bean’s individual section below that you’re concerned about.

Soybean Amino Acid Profile

I’ll start with soybeans, as soy products are the most popular. While products like tofu and tempeh might not have the exact same amino acid profile, it should be similar.

Here’s the amino acid profile of soybeans:

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 270
Threonine (mg) 15 1050 886
Isoleucine (mg) 20 1400 977
Leucine (mg) 39 2730 1589
Lysine (mg) 30 2100 1330
Methionine (mg) 15 1050 270
Phenylalanine (mg) 25 1750 1006
Valine (mg) 26 1820 988
Histidine (mg) 10 700 598

For almost all amino acids, it takes only 1-2 servings of 1 cup of soybeans to reach the RDA for a 70 kg person, which is great.

The only weak point, as with every other type of bean, is methionine. It takes about 4 servings of soybeans to hit the RDA for methionine, which is quite a lot.

Overall, soybeans have one of the best bean amino acid profiles.

Kidney Bean Amino Acid Profile

My personal favorite bean to pair with rice, let’s take a look at the amino acid profile of kidney beans.

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 182
Threonine (mg) 15 1050 646
Isoleucine (mg) 20 1400 678
Leucine (mg) 39 2730 1227
Lysine (mg) 30 2100 1053
Methionine (mg) 15 1050 230
Phenylalanine (mg) 25 1750 830
Valine (mg) 26 1820 804
Histidine (mg) 10 700 428

Again, weak in methionine (needs about 4 servings to hit RDA), but all other amino acid RDAs can be met with about 2 servings of kidney beans.

The only exception is that it takes ~2.5 servings to hit the valine RDA.

Black Bean Amino Acid Profile

Black beans are a very common type of legume to include in vegan recipes.

Let’s look at their profile:

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 181
Threonine (mg) 15 1050 642
Isoleucine (mg) 20 1400 673
Leucine (mg) 39 2730 1218
Lysine (mg) 30 2100 1046
Methionine (mg) 15 1050 229
Phenylalanine (mg) 25 1750 824
Valine (mg) 26 1820 798
Histidine (mg) 10 700 425

Black beans have a very similar amino acid profile to kidney beans. Most amino acid RDAs are met within 2 servings, but valine needs a little more (again about 2.5 servings).

As with all beans, there is a low amount of methionine.

Navy Bean Amino Acid Profile

Navy beans are frequently used in BBQ bean recipes.

Here’s what the profile looks like:

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 182
Threonine (mg) 15 1050 526
Isoleucine (mg) 20 1400 704
Leucine (mg) 39 2730 1274
Lysine (mg) 30 2100 946
Methionine (mg) 15 1050 202
Phenylalanine (mg) 25 1750 857
Valine (mg) 26 1820 917
Histidine (mg) 10 700 375

Navy beans have arguably the most balanced amino acid profile of all the beans. It takes right around 2 servings to meet all RDAs with the typical exception of methionine.

Adzuki Bean Amino Acid Profile

Adzuki beans have the second highest protein content per serving of all the beans here, and one of the best profiles as well:

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 166
Threonine (mg) 15 1050 587
Isoleucine (mg) 20 1400 690
Leucine (mg) 39 2730 1454
Lysine (mg) 30 2100 1304
Methionine (mg) 15 1050 182
Phenylalanine (mg) 25 1750 915
Valine (mg) 26 1820 890
Histidine (mg) 10 700 455

Even the harder to get amino acids, like valine and leucine, are found in decent amounts (takes about 2 servings to reach the RDA).

But the methionine content is lower than the other beans we’ve looked at so far. That shouldn’t be a big deal because you should be getting methionine from other sources.

Mung Bean Amino Acid Profile

Here’s the amino acid profile for mung beans.

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Threonine (mg) 15 1050 465
Isoleucine (mg) 20 1400 600
Leucine (mg) 39 2730 1099
Lysine (mg) 30 2100 990
Methionine (mg) 15 1050 170
Phenylalanine (mg) 25 1750 858
Valine (mg) 26 1820 735
Histidine (mg) 10 700 414

It’s a little low in leucine and valine than the more popular beans, requiring almost 3 servings to meet the RDA.

It’s methionine content is also on the low side relative to most other beans.

Fava Bean Amino Acid Profile

Fava beans have the worst amino acid profile of any bean on this page:

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 122
Threonine (mg) 15 1050 459
Isoleucine (mg) 20 1400 520
Leucine (mg) 39 2730 972
Lysine (mg) 30 2100 826
Methionine (mg) 15 1050 105
Phenylalanine (mg) 25 1750 546
Valine (mg) 26 1820 575
Histidine (mg) 10 700 328

Compared to other foods in general, they’re still good nutritionally, but other beans are almost always a better choice.

Fava beans take more than 2 servings to reach the RDA in tryptophan, isoleucine, leucine, lysine, methionine, phenylalanine, valine, and histidine.

So basically all of them…

Lima Bean Amino Acid Profile

Finally, we have the amino acid profile of lima beans:

RDA RDA Soybeans
mg per kg for 70 kg person 1 cup
Tryptophan (mg) 4 280 151
Threonine (mg) 15 1050 491
Isoleucine (mg) 20 1400 745
Leucine (mg) 39 2730 909
Lysine (mg) 30 2100 765
Methionine (mg) 15 1050 116
Phenylalanine (mg) 25 1750 571
Valine (mg) 26 1820 723
Histidine (mg) 10 700 393

It also has one of the weakest overall profiles.

It’s low in leucine, lysine, methionine, phenylalanine, and valine.

It’s still good to add to meals, but I wouldn’t heavily rely on it over other beans if possible.

Summary

You can reach your RDA for most essential acids with 2-3 servings of most beans.

The exception is that certain beans are low in valine and leucine, and that all beans are low in methionine.

The best beans overall are soybeans, followed by kidney, black, navy, and adzuki beans, which all have similar amino acid profiles.

Fava and lima beans had by far the weakest amino acid profiles, with mung beans not too far behind.

About the author

Dale C.

Your friendly neighborhood vegan from Toronto. Chemical engineer turned semi-professional soccer player and freelance writer. Trying to do my small part in making the world better by writing about the wonderful world of veganism.

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