The 4 Hardest to Get Amino Acids on a Vegan Diet

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Many people believe that you can’t be a vegan athlete because a vegan diet lacks nutrients like specific amino acids.

If you were under that impression, it’s false.

But there is a grain of truth to it. If you don’t vary your protein sources, you’ll likely end up with a suboptimal amount of certain amino acids.

Focus on These 4 Amino Acids

Most vegans focus on plant-based protein sources like legumes and nuts when switching from meat.

Many of these protein sources (but not all) have a relatively low amount of these 4 essential amino acids:

  1. Lysine
  2. Tryptophan
  3. Methionine
  4. Phenylalanine

For example, grains are low in lysine, while legumes tend to be low in methionine.

I’m going to go through each of those amino acids, one-by-one, and go over the top 30 vegan foods that contain them.

The Best Vegan Food Sources of Lysine

lysine molecular structure

There’s no official RDA for lysine, but according to research, you typically want to aim for about 12 mg per kg of bodyweight.

For example, a 170 lb person needs 924 mg per day, or more.

Here are the top 30 vegan foods for lysine.

Food Serving Energy (kcal) Lysine (g)
Soybeans 1 cup 254 1.33
Adzuki beans 1 cup 294 1.304
Lentils 1 cup 230 1.247
Oats 1 cup 607 1.094
Kidney beans 1 cup 225 1.053
Black beans 1 cup 227 1.046
Mung bean 1 cup 212 0.99
Buckwheat groats 1 cup 567 0.976
Chickpeas 1 cup 269 0.973
Navy beans 1 cup 255 0.946
Pumpkin seeds 1 cup 285 0.887
Fava bean 1 cup 187 0.826
Lima beans 1 cup 209 0.765
Pistachio nuts 0.5 cup 344 0.7
Peanuts 0.5 cup 414 0.676
Spinach 1 bunch 78 0.592
Cashew 0.5 cup 393 0.56
Rye grain 1 cup 571 0.483
Swiss chard 10 leafs 91 0.475
Peas 1 cup 117 0.46
Quinoa 1 cup 222 0.442
Sesame seeds 0.5 cup 413 0.41
Hemp seeds 3 tbsp 166 0.383
Pine nuts 0.5 cup 454 0.365
Cowpeas 1 cup 160 0.345
Brazil nut 0.5 cup 438 0.326
White potato 1 large 255 0.321
Almonds 1/2 cup 313 0.307
Chia seeds 3 tbsp 146 0.291
Hazelnut 0.5 cup 424 0.283
Eggplant 1 eggplant 137 0.258

Legumes are great sources of protein, and great sources of many amino acids. Lysine is one of them. Here’s a detailed breakdown of beans amino acids.

Almost all the top results are a bean, and lentils are right up there as well.

Most grains are relatively low in lysine (as are nuts), but oats have a fair amount. This is part of the reason why it can be troubling to say that “grains have a low amount of lysine” when not every single one does. Each food has its own amino acid profile.

The Best Vegan Food Sources of Methionine

methionine

Next up is methionine, where you should be aiming for at least 14 mg per kg of bodyweight.

For a 170 lb (77 kg) person, that’s about 1.1 grams per day.

Now let’s look at the top 30 vegan foods for methionine.

Food Serving Energy (kcal) Methionine (g)
Brazil nut 0.5 cup 438 0.747
Oats 1 cup 607 0.487
Sesame seeds 0.5 cup 413 0.422
Hemp seeds 3 tbsp 166 0.28
Soybeans 1 cup 254 0.27
Pumpkin seeds 1 cup 285 0.267
Rye grain 1 cup 571 0.259
Buckwheat groats 1 cup 567 0.251
Peanuts 0.5 cup 414 0.231
Kidney beans 1 cup 225 0.23
Black beans 1 cup 227 0.229
Pistachio nuts 0.5 cup 344 0.221
Navy beans 1 cup 255 0.202
Chickpeas 1 cup 269 0.19
Cashew 0.5 cup 393 0.188
Adzuki beans 1 cup 294 0.182
Spinach 1 bunch 78 0.18
Quinoa 1 cup 222 0.178
Chia seeds 3 tbsp 146 0.176
Pine nuts 0.5 cup 454 0.175
Mung bean 1 cup 212 0.17
Lentils 1 cup 230 0.152
Hazelnut 0.5 cup 424 0.149
Walnut 0.5 cup 383 0.138
Peas 1 cup 117 0.119
Lima beans 1 cup 209 0.116
Fava bean 1 cup 187 0.105
Rice 1 cup 205 0.1
Corn 1 ear 123 0.096
White potato 1 large 255 0.096

Legumes still do alright, but the top results are dominated by nuts, seeds, and grains.

Seeds have fairly conformed amino acid profiles, so it’s not surprising to see sesame, hemp, and pumpkin seeds all in the top 10.

Grains like oats, rye, and buckwheat also rank very high for methionine.

Finally, a few types of nuts, like the brazil nut, and pistachios also have a good amount of methionine.

You’ll need around 2 servings of any of the top 10 foods to meet your RDA.

The Best Vegan Food Sources of Tryptophan

tryptophan

The RDA for tryptophan is 5 mg per kg of bodyweight, much lower than the 2 amino acids above.

For a 77 kg (170 lb) person, that’s just 385 mg per day, which is easy to get if you eat the right foods.

Those “right foods” include any on this list of the best vegan tryptophan sources:

Food Serving Energy (kcal) Tryptophan (g)
Oats 1 cup 607 0.365
Buckwheat groats 1 cup 567 0.279
Sesame seeds 0.5 cup 413 0.279
Soybeans 1 cup 254 0.27
Pumpkin seeds 1 cup 285 0.209
Rye grain 1 cup 571 0.183
Kidney beans 1 cup 225 0.182
Navy beans 1 cup 255 0.182
Peanuts 0.5 cup 414 0.182
Black beans 1 cup 227 0.181
Adzuki beans 1 cup 294 0.166
Cashew 0.5 cup 393 0.162
Lentils 1 cup 230 0.16
Mung bean 1 cup 212 0.154
Pistachio nuts 0.5 cup 344 0.154
Lima beans 1 cup 209 0.151
Chickpeas 1 cup 269 0.139
Spinach 1 bunch 78 0.133
Chia seeds 3 tbsp 146 0.131
Hazelnut 0.5 cup 424 0.13
Fava bean 1 cup 187 0.122
Almonds 1/2 cup 313 0.114
Hemp seeds 3 tbsp 166 0.111
Walnut 0.5 cup 383 0.099
Quinoa 1 cup 222 0.096
Brazil nut 0.5 cup 438 0.09
Swiss chard 10 leafs 91 0.082
Pine nuts 0.5 cup 454 0.072
Seaweed (dried) 1 tbsp 20 0.065
White potato 1 large 255 0.063
Cowpeas 1 cup 160 0.061
Flaxseed 2 tbsp 110 0.061

Oats are again near the top, which was surprising to me. They may not have a ton of protein overall, but they have a relatively high amount of some important vegan amino acids. Buckwheat and rye grain are also high in tryptophan.

On top of grains, seeds and legumes are both good sources of tryptophans, in particular sesame and pumpkin seeds.

The Best Vegan Food Sources of Phenylalanine

phenylalanine

Finally, phenylalanine has an RDA of 33 mg per kg of bodyweight.

Again, for a 170 lb (77 kg) person, this is 2541 mg (2.541 g) per day.

Here are the top 30 vegan sources of phenylalanine.

Food Serving Energy (kcal) Phenylalanine (g)
Oats 1 cup 607 1.396
Soybeans 1 cup 254 1.006
Peanuts 0.5 cup 414 1.005
Adzuki beans 1 cup 294 0.915
Lentils 1 cup 230 0.881
Mung bean 1 cup 212 0.858
Navy beans 1 cup 255 0.857
Kidney beans 1 cup 225 0.83
Black beans 1 cup 227 0.824
Chickpeas 1 cup 269 0.779
Buckwheat groats 1 cup 567 0.756
Rye grain 1 cup 571 0.735
Sesame seeds 0.5 cup 413 0.677
Pistachio nuts 0.5 cup 344 0.672
Almonds 1/2 cup 313 0.611
Pumpkin seeds 1 cup 285 0.591
Lima beans 1 cup 209 0.571
Fava bean 1 cup 187 0.546
Cashew 0.5 cup 393 0.542
Swiss chard 10 leafs 91 0.528
Hazelnut 0.5 cup 424 0.448
Macadamia nut 0.5 cup 481 0.446
Spinach 1 bunch 78 0.439
Hemp seeds 3 tbsp 166 0.434
Brazil nut 0.5 cup 438 0.425
Walnut 0.5 cup 383 0.416
Pine nuts 0.5 cup 454 0.354
Quinoa 1 cup 222 0.342
Chia seeds 3 tbsp 146 0.305
Peas 1 cup 117 0.29

The magical grain oats again tops this list.

That’s followed by all the legumes, ranging from beans to peanuts to lentils.

Summary

Legumes in general are great or at least decent sources of all the most important vegan amino acids.

Surprisingly, oats are also a fantastic source of all 4 hard to get amino acids on a vegan diet, so don’t be afraid to eat more oatmeal.

Finally, seeds are a nice way to get a good amount of methionine, tryptophan, and phenylalanine.

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.