What is a well balanced mixture of all eight amino acids?

November 11, 2025 •

3 min read

Over 55% of the total protein found in a 174-gram braised chicken breast consists of complete protein, which represents a well-balanced mixture of all eight amino acids, also known as essential amino acids. A balanced intake is vital for supporting bodily functions, including tissue repair, muscle growth, and metabolism.

Quick Summary

A well-balanced mixture of amino acids, or complete protein, contains all nine essential amino acids in sufficient quantities. Animal products, soy, quinoa, and other plant combinations provide the full profile for optimal body function and protein synthesis. Understanding dietary requirements helps maintain overall health.

Key Points

Complete Proteins: A complete protein contains all nine essential amino acids needed by the human body.
Essential Amino Acids: There are nine, not eight, essential amino acids that the body cannot produce and must be obtained from food.
Sources: Animal products like meat, eggs, and dairy, as well as plant-based foods like soy and quinoa, are complete proteins.
Complementary Proteins: Vegetarians and vegans can get all essential amino acids by combining different plant-based foods throughout the day, like rice and beans.
Daily Intake: The body can utilize essential amino acids consumed over a 24-hour period, so they don't need to be consumed in a single meal.
Balance is Key: An insufficient amount of even one essential amino acid can limit the body's ability to create proteins, impacting various bodily functions.

The Essentials of Amino Acid Balance

Protein is a crucial macronutrient made of amino acids. The body can produce 11 of the 20 necessary amino acids, but nine are 'essential' and must be obtained through diet. These nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. (The user's query refers to eight, but current understanding, including sources like MedlinePlus, confirms nine essential amino acids for adults.) A food source providing a sufficient amount of all nine is known as a 'complete protein'.

Why a Balanced Amino Acid Profile Matters

For the body to synthesize new proteins effectively for muscle building, hormone production, and tissue repair, it requires all essential amino acids. If one essential amino acid is lacking, it becomes a 'limiting amino acid,' restricting the body's ability to use the others and slowing protein synthesis. This concept, formerly protein combining at every meal, is now understood to be manageable over the course of a day.

Complete vs. Incomplete Protein Sources

Understanding where to find a balanced amino acid mixture is key to nutritional health, especially for those on restricted diets. Animal products are the most straightforward complete proteins, but many plant-based foods can also provide a complete profile, individually or through careful combinations.

Complete Protein Sources

Animal Products: Meat, poultry, fish, eggs, and dairy products are excellent examples of complete proteins that offer all essential amino acids in one source.
Plant-Based Foods: A few plant sources also contain all nine essential amino acids, making them valuable in a vegetarian or vegan diet.
- Soy products (e.g., tofu, edamame)
- Quinoa
- Buckwheat

Complementary Protein Sources

Combining different protein sources throughout the day is a reliable way to ensure a balanced intake of all essential amino acids for those relying on a plant-based diet.

Legumes with Grains: Beans with rice is a classic pairing where the amino acids missing in one food are supplied by the other.
Nuts/Seeds with Legumes: Combining seeds with chickpeas (like in hummus) can create a full protein profile.
Legumes with Grains: Lentils with whole-grain bread or pasta is another example of a complementary pairing.

The Importance of Variety and Timing

Years ago, it was believed that complementary proteins needed to be eaten in the same meal, but research has shown that the body can use amino acids consumed over a 24-hour period to form complete proteins. This gives individuals, especially those on a vegan or vegetarian diet, much greater flexibility. A varied diet that includes a wide range of protein sources throughout the day is generally sufficient for most people.

Recommended Daily Intake Ratios

While specific ratios are not typically necessary to track for most healthy individuals consuming a varied diet, understanding general guidelines from reputable health organizations can be insightful. The World Health Organization (WHO) provides daily required intakes for essential amino acids per kilogram of body weight for adults.


Essential Amino Acid	WHO Recommended Daily Intake (mg/kg of body weight)	Example for a 70 kg (154 lb) Adult (mg)
Histidine	10 mg	700 mg
Isoleucine	20 mg	1,400 mg
Leucine	39 mg	2,730 mg
Lysine	30 mg	2,100 mg
Methionine (total sulfur amino acids)	10.4 mg	728 mg
Phenylalanine (total aromatic amino acids)	25 mg	1,750 mg
Threonine	15 mg	1,050 mg
Tryptophan	4 mg	280 mg
Valine	26 mg	1,820 mg

*Note: The combined requirements for Methionine + Cystine and Phenylalanine + Tyrosine are also often referenced, as the body can synthesize one from the other.

Conclusion: Meeting Your Amino Acid Needs

A well-balanced mixture of all eight (or rather, nine) essential amino acids is what's found in a high-quality, complete protein source. For most people, this is a natural outcome of a varied and healthy diet. Animal proteins are a simple way to achieve this, but a thoughtfully planned plant-based diet, rich in diverse protein sources, is just as effective. Consume a variety of protein-rich foods over the day to ensure all essential building blocks are available for optimal bodily function.

This article offers general nutritional information and is not a substitute for medical advice. Please consult a healthcare professional for personalized dietary recommendations.

For more detailed nutritional guidelines, consider exploring resources like the National Institutes of Health (NIH) publications on proteins and amino acids, which provide comprehensive data and research insights.

Frequently Asked Questions

The primary function is to provide the body with all the necessary building blocks for protein synthesis, which is crucial for building and repairing tissues, producing hormones and enzymes, and supporting metabolic processes.

While many plant-based proteins are 'incomplete' and lack one or more essential amino acids, some, like soy and quinoa, are complete proteins. Combining various plant-based foods throughout the day can also create a complete protein profile.

No, it is not necessary. The body can effectively combine amino acids from different meals consumed over a 24-hour period to meet its protein synthesis needs.

The nine essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Leucine is a branched-chain amino acid (BCAA) that is particularly important for stimulating muscle protein synthesis and repair, making it highly valued in the fitness community.

Yes, although it is rare in developed countries with varied diets. Deficiency can lead to issues with growth, energy levels, and overall bodily function, especially if a diet relies too heavily on a limited range of incomplete proteins.

Dietary requirements for essential amino acids generally decrease with age. Infants and growing children have significantly higher protein and essential amino acid needs than adults.

A limiting amino acid is the essential amino acid in shortest supply relative to the body's needs. Its limited availability can restrict the body's overall protein synthesis, even if other amino acids are plentiful.