Nuts are one of the best bulking foods due to their high caloric content.
There’s also a decent amount of protein in nuts, making them a great snack.
While you want to be mindful of the omega 3 to 6 fat ratio of nuts, you also want to make sure you’re eating other protein sources that compensate for any low amounts of individual amino acids in nuts.
As long as you’re eating the complementary amino acids within the same day or so, there’s nothing to worry about.
Table of Contents
The Limiting Amino Acids of Nuts
I collected amino acid data for all common nuts, and then calculated how many servings of each nut would it take to reach the RDA for each essential amino acid.
We focus on essential amino acids, because they’re the only ones you need to pay any real attention to in your diet.
You can click to expand the image below (it should open in a new tab in a larger size):
We see a few things stand out in red (indicating many required servings to reach RDA):
- Almost all nuts have low amounts of lysine and methionine.
- Peanuts and pistachios are fairly well balanced.
- Macadamia nuts have low amounts of all essential amino acids. They mostly contain non-essential amino acids.
When we talk about a limiting amino acid of nuts, it’s pretty clear that lysine and methionine are both limiting amino acids.
For vegans, the best plant-based sources of lysine are pretty much any type of bean and oats.
Methionine is just generally tough to get on a vegan diet, Brazil nuts are actually the best source, followed by oats, seeds (hemp, sesame, etc.), and beans.
Non-vegans can get a lot of both lysine and methionine from animal products like beef, cheese, and turkey.
Peanut Amino Acid Profile
You say legume, I say nut.
I have the tendency to eat a lot of peanuts and peanut butter, so I was particularly interested in the essential amino acid profile of peanuts.
The far right column will tell you how many milligrams of an amino acid is in a 0.5 cup serving of peanuts. Compare this one to the column beside it, which is the RDA for that amino acid (in mg) for a 70 kg (154 lb) person.
| RDA | RDA | Peanuts | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 182 |
| Threonine (mg) | 15 | 1050 | 645 |
| Isoleucine (mg) | 20 | 1400 | 662 |
| Leucine (mg) | 39 | 2730 | 1221 |
| Lysine (mg) | 30 | 2100 | 676 |
| Methionine (mg) | 15 | 1050 | 231 |
| Phenylalanine (mg) | 25 | 1750 | 1005 |
| Valine (mg) | 26 | 1820 | 790 |
| Histidine (mg) | 10 | 700 | 476 |
You’ll hit your RDA of most essential amino acids with just a few servings of peanuts. The only ones that take more are lysine and methionine, as is expected.
Walnut Amino Acid Profile
Walnuts have quite a few limiting amino acids.
Take a look at the data:
| RDA | RDA | Walnuts | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 99 |
| Threonine (mg) | 15 | 1050 | 349 |
| Isoleucine (mg) | 20 | 1400 | 366 |
| Leucine (mg) | 39 | 2730 | 684 |
| Lysine (mg) | 30 | 2100 | 248 |
| Methionine (mg) | 15 | 1050 | 138 |
| Phenylalanine (mg) | 25 | 1750 | 416 |
| Valine (mg) | 26 | 1820 | 441 |
| Histidine (mg) | 10 | 700 | 229 |
You need at least 3 servings (so 1.5 cups total) of walnuts to meet any of the RDAs. If you’re larger than 70 kg, you’ll have to eat even more.
Walnuts are very limited in lysine and methionine, but also fairly deficient in leucine, isoleucine, valine, and phenylalanine.
Basically, don’t rely on walnuts too much for protein.
Pine Nut Amino Acid Profile
I don’t know many people who could afford to eat a large amount of pine nuts on a regular basis, but let’s look at their essential amino acid breakdown anyways.
| RDA | RDA | Pine nuts | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 72 |
| Threonine (mg) | 15 | 1050 | 250 |
| Isoleucine (mg) | 20 | 1400 | 366 |
| Leucine (mg) | 39 | 2730 | 669 |
| Lysine (mg) | 30 | 2100 | 365 |
| Methionine (mg) | 15 | 1050 | 175 |
| Phenylalanine (mg) | 25 | 1750 | 354 |
| Valine (mg) | 26 | 1820 | 464 |
| Histidine (mg) | 10 | 700 | 230 |
Pine nuts have a pretty even distribution of amino acids. They’re not great for any particular one, but not horrible either.
It takes 3-4 servings to reach the RDA for most of the amino acids.
Hazelnut Amino Acid Profile
Here’s another expensive nut that most people don’t eat much of unless they really like hazelnut butter spreads.
| RDA | RDA | Hazelnut | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 130 |
| Threonine (mg) | 15 | 1050 | 335 |
| Isoleucine (mg) | 20 | 1400 | 368 |
| Leucine (mg) | 39 | 2730 | 718 |
| Lysine (mg) | 30 | 2100 | 283 |
| Methionine (mg) | 15 | 1050 | 149 |
| Phenylalanine (mg) | 25 | 1750 | 448 |
| Valine (mg) | 26 | 1820 | 473 |
| Histidine (mg) | 10 | 700 | 292 |
Its profile is pretty typical for a nut.
Decent for most amino acids, but very bad for lysine and methionine. Nothing else really stands out.
Brazil Nut Amino Acid Profile
Brazil nuts have the most interesting nut profile to me. Pay special attention to its methionine content.
| RDA | RDA | Brazil nut | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 90 |
| Threonine (mg) | 15 | 1050 | 243 |
| Isoleucine (mg) | 20 | 1400 | 344 |
| Leucine (mg) | 39 | 2730 | 791 |
| Lysine (mg) | 30 | 2100 | 326 |
| Methionine (mg) | 15 | 1050 | 747 |
| Phenylalanine (mg) | 25 | 1750 | 425 |
| Valine (mg) | 26 | 1820 | 505 |
| Histidine (mg) | 10 | 700 | 272 |
It is the only nut that takes less than 2 servings to hit the RDA for a 70 kg person.
For some reason, Brazil nuts have a ton of methionine, so they’re definitely worth adding to your mix of nuts if possible.
Other than that, they have a pretty typical profile for a nut, decent in most amino acids, but low in lysine.
Macadamia Nut Amino Acid Profile
Macadamia nuts are the worst nuts by far if you’re eating them specifically to get more essential amino acids.
It’s fine to eat some, just don’t make them a major protein source.
| RDA | RDA | Macadamia nut | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 45 |
| Threonine (mg) | 15 | 1050 | 248 |
| Isoleucine (mg) | 20 | 1400 | 210 |
| Leucine (mg) | 39 | 2730 | 403 |
| Lysine (mg) | 30 | 2100 | 12 |
| Methionine (mg) | 15 | 1050 | 15 |
| Phenylalanine (mg) | 25 | 1750 | 446 |
| Valine (mg) | 26 | 1820 | 243 |
| Histidine (mg) | 10 | 700 | 131 |
Macadamia nuts are insanely low in both lysine and methionine. It would take hundreds of servings to reach the lysine RDA.
Other than those 2 amino acids, macadamia nuts are still low in just about every essential amino acid.
Pistachio Nut Amino Acid Profile
Pistachio nuts have a very good essential amino acid profile (for a nut anyways).
Let’s take a look:
| RDA | RDA | Pistachio nuts | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 154 |
| Threonine (mg) | 15 | 1050 | 421 |
| Isoleucine (mg) | 20 | 1400 | 564 |
| Leucine (mg) | 39 | 2730 | 986 |
| Lysine (mg) | 30 | 2100 | 700 |
| Methionine (mg) | 15 | 1050 | 221 |
| Phenylalanine (mg) | 25 | 1750 | 672 |
| Valine (mg) | 26 | 1820 | 768 |
| Histidine (mg) | 10 | 700 | 315 |
For most of the amino acids, it takes just 2-3 servings to exceed the RDA.
It’s really only very low in methionine, which would take about 5 servings to hit the RDA. Pair pistachios with Brazil nuts and you have a fairly decent complete protein snack.
Cashew Amino Acid Profile
The amino acid profile for cashews is very similar to pistachios, which puts it at the top of the nuts in terms of quality.
It’s just a bit worse for most than pistachios, but not significantly.
| RDA | RDA | Cashew | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 162 |
| Threonine (mg) | 15 | 1050 | 406 |
| Isoleucine (mg) | 20 | 1400 | 501 |
| Leucine (mg) | 39 | 2730 | 880 |
| Lysine (mg) | 30 | 2100 | 560 |
| Methionine (mg) | 15 | 1050 | 188 |
| Phenylalanine (mg) | 25 | 1750 | 542 |
| Valine (mg) | 26 | 1820 | 712 |
| Histidine (mg) | 10 | 700 | 273 |
Again, you can hit the RDA for most amino acids in 2-3 servings.
They’re quite low in methionine, and the lysine content is on the low side as well, as expected.
However, cashews are a fairly decent source of tryptophan.
Almond Amino Acid Profile
Almonds are very easy to eat in large quantities if you eat almond butter or bake with almond flour.
Their essential amino acid profile is pretty average for nuts:
| RDA | RDA | Almonds | |
| mg per kg | for 70 kg person | 0.5 cup | |
| Tryptophan (mg) | 4 | 280 | 114 |
| Threonine (mg) | 15 | 1050 | 325 |
| Isoleucine (mg) | 20 | 1400 | 406 |
| Leucine (mg) | 39 | 2730 | 795 |
| Lysine (mg) | 30 | 2100 | 307 |
| Methionine (mg) | 15 | 1050 | 85 |
| Phenylalanine (mg) | 25 | 1750 | 611 |
| Valine (mg) | 26 | 1820 | 462 |
| Histidine (mg) | 10 | 700 | 291 |
Very low in both lysine and methionine, and decent for most others. Valine is a bit on the low side as well.
Summary
Nuts can be a nice protein source, especially if you’re bulking, but the average nut is very deficient in lysine and methionine.
Brazil nuts strangely have a ton of methionine, so they pair well with other nuts.
In terms of overall essential amino acid content, the most well-rounded nuts are peanuts, pistachios, and cashews.
To get enough lysine and methionine from other sources, focus on eating beans, oats, and seeds.
Can You Eat Too Many Nuts?
In most cases, eating a few small servings of nuts per day is ideal.
Eating more than that may give you a decent amount of protein and some nutrients, but also comes with 2 big concerns:
- Calories – It’s very easy to go over your maintenance level of calories if you enjoy nuts, which makes it easy to gain weight unintentionally.
- High Omega 6 fat content – Most nuts have a bad omega 3 to 6 fat ratio. Having a poor ratio in your diet, usually as a result of eating foods high in omega 6 fats like nuts, can lead to inflammation, which can lead to a wide variety of negative side effects.
Nuts can certainly play a role in a healthy diet, but unless you have a good reason, you should limit your consumption of nuts to small portions.
