What Are Essential Amino Acids?
A practical guide to essential amino acids, the difference between EAAs and BCAAs, dietary sources, and where amino-acid supplements fit into the broader nutrition picture.
What Are Amino Acids?
Amino acids are organic compounds that the body uses to build proteins. Dietary protein is therefore an important part of normal nutrition.
There are 20 amino acids commonly used to build proteins in the human body. They can be described according to whether the body can make them itself or whether they need to be obtained from dietary sources.
What Makes An Amino Acid "Essential"?
An essential amino acid is one that the body cannot produce in sufficient amounts and therefore needs to obtain from dietary sources.
There are nine essential amino acids:
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
Essential Amino Acids At A Glance
Histidine
One of the nine amino acids classified as essential in human nutrition.
Isoleucine
An essential amino acid and one of the three branched-chain amino acids.
Leucine
An essential amino acid and one of the three branched-chain amino acids.
Lysine
An essential amino acid obtained through dietary sources.
Methionine
An essential amino acid that is part of dietary protein.
Phenylalanine
An essential amino acid obtained through the diet.
Threonine
An essential amino acid required as part of normal protein nutrition.
Tryptophan
An essential amino acid that needs to come from dietary sources.
Valine
An essential amino acid and one of the three branched-chain amino acids.
EAA vs. BCAA: What's The Difference?
BCAA stands for branched-chain amino acids. The three BCAAs are leucine, isoleucine, and valine.
These three amino acids are also part of the nine essential amino acids. "EAA" refers to the broader group of nine essential amino acids, while "BCAA" refers specifically to those three branched-chain amino acids.
| Term | Meaning | Examples |
|---|---|---|
| EAA | The group of nine essential amino acids. | Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. |
| BCAA | A subgroup of three branched-chain essential amino acids. | Leucine, isoleucine, and valine. |
Where Do Essential Amino Acids Come From?
Essential amino acids can be obtained through protein-containing foods. The amount and balance of individual amino acids can differ between foods.
Animal-Based Protein
Foods such as eggs, dairy products, fish, meat, and poultry provide protein and essential amino acids.
Plant-Based Protein
Legumes, grains, nuts, seeds, soy foods, and other plant foods can contribute protein and amino acids to the diet.
Varied Diet
A varied diet can combine different protein-containing foods to provide essential amino acids.
Where Do EAA Supplements Fit?
EAA supplements provide selected essential amino acids in a concentrated form. They are available in different formats, including tablets, capsules, powders, and other formulations.
When evaluating an EAA supplement, it can be useful to review the ingredient profile, serving size, product format, dietary information, and cost per serving.
What Should You Compare In An EAA Supplement?
Ingredient Profile
Check which essential amino acids are included and how clearly the formulation is presented.
Serving Size
Compare the stated serving size and how many units are required for one serving.
Servings Per Container
Check the actual number of servings rather than relying only on container size.
Cost Per Serving
Cost per serving can provide a more useful comparison than bottle price alone.
Dietary Information
Review product information that relates to dietary preferences and ingredient exclusions.
Current Product Label
Check the current supplement facts panel and manufacturer's information before purchasing.
Essential Amino Acid Questions
Are EAAs only found in supplements?
No. Essential amino acids naturally occur in protein-containing foods. Supplements provide another way to consume selected amino acids.
Are EAAs and BCAAs the same thing?
No. BCAAs are three specific amino acids — leucine, isoleucine, and valine — while EAAs refers to the broader group of nine essential amino acids.
Do I need an EAA supplement?
That depends on an individual's overall diet and circumstances. A supplement should not automatically be assumed to be necessary.
What should I check before buying one?
Review the ingredients, serving size, servings per container, dietary information, format, current price, and manufacturer information.
Related NutriFit Journal Resources
Understanding The Basics Comes First
Understanding what essential amino acids are can make it easier to read supplement labels, compare products, and decide which information matters most to you.
This article provides general educational information and is not a substitute for professional medical or nutritional advice.
NutriFit Journal provides general informational content and does not provide medical advice, diagnosis, or treatment. This content is not a substitute for advice from a qualified healthcare professional.
Dietary supplements are not intended to diagnose, treat, cure, or prevent disease.