Protein building blocks: “Essential” information about amino acid sources

Behind every powerful protein source are building blocks: amino acids. Learn which amino acids are essential, the top amino acid sources, and how to get the proper amounts to optimize your health.

What are amino acid sources, and why do they matter for health?

Amino acids are the "building blocks" of proteins. They combine to form the proteins that make muscles, skin, enzymes, and hormones. Your body uses 20 different amino acids to produce these proteins, and there are three main types: essential, conditionally essential, and non-essential. You can get amino acids from a variety of food sources.

The “essential 9” amino acids

These amino acids must come from your diet because your body cannot produce them.

Amino acid	Notes	Top food sources
Histidine	Helps make histamine, which contributes to immune function, digestion, sleep, and sexual function.	Meat, fish, poultry, nuts, seeds, and whole grains.
Isoleucine	A branched-chain amino acid (BCAA) that can be an energy source; helps with immune function and muscle metabolism.	Meat, fish, poultry, eggs, dairy, and legumes.
Leucine	A branched-chain amino acid (BCAA) that can be an energy source; used for hormone production, muscle growth, and wound healing.	Meat, fish, poultry, eggs, dairy, and legumes.
Lysine	Used for hormone and energy production, immune function, and calcium balance.	Meat, poultry, fish, eggs, and legumes.
Methionine	Helps with tissue growth, metabolism, and detoxification. Assists mineral absorption, including zinc and selenium.	Eggs, meat, fish, whole grains, and Brazil nuts.
Phenylalanine	Produces brain chemical messengers. People with the rare genetic condition phenylketonuria (PKU) cannot break down this amino acid and must limit intake.	Meat, fish, dairy, eggs, and legumes. The low-calorie sweetener aspartame contains phenylalanine.
Threonine	Used to form glycine, which helps control muscle movements. Helps make collagen and elastin, which are needed for skin health.	Beef, dairy, eggs, poultry, and legumes.
Tryptophan	Helps make serotonin, a brain chemical that helps regulate mood, sleep, and appetite.	Dairy, poultry, eggs, nuts, and seeds.
Valine	Participates in muscle growth and tissue repair. A branched-chain amino acid (BCAA) that can be an energy source.	Meat, seafood, dairy, eggs, and legumes.

Conditionally essential amino acids

These amino acids may become “essential” in situations like stress, illness, and growth, when the body cannot produce them sufficiently.

Amino acid	Notes	Top food sources
Arginine	Helps increase blood flow. A common sports nutrition supplement.	Meat, poultry, seafood, legumes, nuts, and seeds (especially pumpkin seeds)
Cysteine	Made from methionine and contributes to methionine needs.	Meat, poultry, seafood, eggs, and whole grains.
Glutamine	Used to build other amino acids and has roles in ammonia (waste) removal and brain and gut health.	Meat, dairy, nuts, whole grains, and legumes.
Tyrosine	Used to make important brain chemicals. Made from phenylalanine and counts toward phenylalanine needs.	Meat, dairy, seafood, eggs, and legumes.
Glycine	Needed for collagen production and brain health.	Gelatin, meat, pork skin, chicken skin, bone broth, and legumes.
Proline	Needed for collagen production.	Gelatin, meat, seafood, and dairy.

Non-essential amino acids

These amino acids do not need to come from your diet since your body can make them, but they are still vital for building proteins:

• Alanine
• Asparagine
• Aspartic acid
• Glutamic acid
• Serine

Other important amino acids

Taurine is used to produce energy rather than to make protein. It occurs naturally in animal foods and is often an ingredient in energy drinks.

Hydroxyproline is made from proline and is needed for collagen production, but it is not one of the main 20 amino acids used to build proteins. Rich sources for this amino acid include eggs, bone broth, and gelatin.

Protein completeness and quality

Foods considered “complete proteins” contain all nine essential amino acids in sufficient quantities. All animal and some plant proteins, such as soy and quinoa, are considered complete. However, our body can store and use amino acids throughout the day, so you don't need to get all the amino acids in one meal.

“Protein quality” refers to the quantity of amino acids and how well the proteins are digested and absorbed. For example, eggs and tofu are considered high-quality protein sources.

Here's the good news: you don't need to get all your amino acids from one food or meal. Different foods have different amino acid strengths, so incorporating a wide range of protein sources will cover your needs.

Vegetarian or vegan diets

Plant-based proteins have all the essential amino acids our bodies need. However, they're often not as easy to digest and may be lower in specific amino acids. According to the Academy of Nutrition and Dietetics, this is not of concern to most people who eat a variety of plant proteins throughout the day. Their diet provides enough protein and calories. Vegetarians or vegans don't need to worry about selecting “complementary” plant protein (such as beans + rice) at each meal.

Athletes

Athletes might benefit from essential amino acid supplements to support muscle gain or prevent muscle breakdown if their dietary intake is insufficient or they engage in intense training that increases their protein needs.

Branched-chain amino acids may support muscle recovery, and arginine may enhance athletic performance by increasing blood flow. However, there is limited evidence to support using these supplements, and most athletes who consume an adequate diet do not need them.

Should I take amino acid supplements?

Amino acid supplements may be helpful in specific situations, such as intense training, muscle recovery, or insufficient dietary protein. Before starting supplements, check with your healthcare provider to ensure they're necessary and safe for your health goals.

Track your amino acid intake with MyNetDiary

You can track your amino acid intake from foods and supplements with MyNetDiary Premium. Learn more about customizing your nutrient tracking by watching this video.

Note: You will notice some foods lacking this information since manufacturers do not have to provide amino acid values. You can minimize missing data by logging generic versions of foods whenever possible.

Small but mighty

Amino acids might be small, but their impact on your health is mighty. Ensuring you meet your amino acid needs is a smart step toward achieving your health goals.

Still new to MyNetDiary? Learn more today by downloading the app for FREE.

Related content

How to meet your protein needs for muscle gain in 5 easy steps

Protein powder pros and cons: What to look for to support weight loss, plus some of our favorite recipes

The benefits of eating protein for healthy and achievable weight loss

Nutrients->Protein