It is surprisingly difficult to find the amino acid profile of nutritional yeast.
I had to dig around for a while, but eventually I found a study that had it (1).
The table below shows the data from that study, plus the amount needed to be considered a complete protein by the World Health Organization (WHO).
Essential Amino Acid Profile of Nutritional Yeast
Note that amino acid profiles always fluctuate a bit depending on the manufacturer (for all foods, not just yeast), but this gives us a good idea of what to expect.
Note that “mg/g” means that there is the number of milligrams (mg) of that amino acid per gram of protein overall in the food.
| Essential Amino Acid | Yeast mg/g protein | Complete protein mg/g (2) |
|---|---|---|
| Threonine | 46 | 23 |
| Valine | 49 | 39 |
| Isoleucine | 37 | 30 |
| Leucine | 64 | 59 |
| Phenylalanine | 33 | 30 |
| Lysine | 65 | 45 |
| Methionine | 14 | 16 |
| Tryptophan | 10 | 6 |
It’s a very balanced profile and overall healthy food, and it’s really hard to eat too much nutritional yeast in a day.
Is Nutritional Yeast a Complete Protein?
A “complete protein” means that you can essentially thrive eating sole that protein source. Of course, you’ll be eating other protein sources than nutritional yeast, so it’s not that big of a concern.
Still, I think it’s safe to say that nutritional yeast is a complete protein, or extremely close to it based on the thresholds defined by the World Health Organization (WHO) that I’ve included in the table above.
Even though it falls a tiny bit short on methionine, that’s not really a fair comparison. The 16 mg/g from WHO is for methionine plus cysteine. The data for cysteine wasn’t available for nutritional yeast in the study, but it’s a safe bet that it’s over 2.
Regardless, here’s a list of the best plant-based methionine food sources if you’re interested.
In addition to being well balanced, it has a significant amount of protein as well.
In one quarter cup of nutritional yeast, there’s:
- 60 calories
- 8 grams of protein (32 calories)
- 0.5 grams of fat
- 5 grams carbohydrates (3 grams fiber)
Over half the calories come from protein. It’s no surprise that nutritional yeast is included in many vegan high protein recipes.
Additionally, there are a ton of B vitamins, which people on a plant-based diet sometimes lack.
Is Nutritional Yeast a Good Source of Protein?
Most people somewhere around 100 grams of protein per day. See our guide to vegan protein to get a more specific amount.
Even if you had a full quarter cup of nutritional yeast per day, that’s only 8 grams of protein.
And that’s a lot of nutritional yeast.
In other words, nutritional yeast is not going to be a primary source of protein in a vegan diet.
It’s still great to add on top of food when you can, but you probably won’t plan your diet around it like you would with foods like legumes.
Best Foods to Pair With Nutritional Yeast
If we’re talking in terms of taste, nutritional yeast goes well with just about anything you might put parmesan on:
- Pasta
- Chili
- Popcorn
- Soup
- Garlic bread
If we’re talking in terms of pairing proteins together, which is completely optional, but a bodybuilder might want to, we’re looking for protein sources high in methionine. If you’re plant-based, this includes foods like:
- Seitan (vital wheat gluten) – Nutritional yeast rounds out vital wheat gluten’s amino acid profile and vice versa, plus seitan usually includes nutritional yeast for flavor reasons anyways.
- Seeds – Most types of seeds are among the best methionine sources (pumpkin, sesame, hemp).
- Certain grains – Foods like oats and rye have quite a bit of methionine, although nutritional yeast doesn’t really go too well with them in most cases based on taste.
