How many amino acids do I need per day?

November 12, 2025 •

3 min read

Over 20 amino acids are vital for bodily functions, with nine being essential and sourced only from food. Determining how many amino acids do I need per day is more complex than a single number, as requirements vary based on factors like body weight, age, and activity level.

Quick Summary

This guide explains the difference between essential and non-essential amino acids, outlines individual daily requirements based on body weight, and provides dietary strategies to ensure adequate intake through whole foods and protein sources.

Key Points

Daily needs are individual: The number of amino acids you need per day depends on your body weight, with specific milligram recommendations per kilogram for each of the nine essential amino acids.
Essential amino acids (EAAs) are key: Your body produces non-essential amino acids, so focus on getting the nine essential ones from your diet, including histidine, leucine, and lysine.
Complete proteins are efficient: Sources like meat, eggs, and dairy contain all essential amino acids, making it simple to meet your needs.
Vary plant-based foods: Vegetarians and vegans can get all EAAs by consuming a variety of plant-based protein sources like legumes, grains, and nuts throughout the day.
Athletes have higher requirements: Those with higher physical activity levels need more protein to support muscle growth and repair, potentially benefiting from targeted amino acid supplements.
Whole foods are the best source: Relying on a balanced diet rich in protein is the most natural way to ensure sufficient intake and receive a broader range of nutrients.
Supplements are an option, but not always necessary: While supplements can aid specific goals, most people meet their amino acid requirements through diet alone and should consult a doctor before starting new supplements.

Understanding the building blocks of protein

Amino acids are the fundamental building blocks of proteins, which perform a vast array of critical functions throughout the body. There are 20 standard amino acids that the human body uses, which are categorized into three groups: essential, non-essential, and conditionally essential. The body can synthesize non-essential amino acids on its own, but the nine essential amino acids must be obtained through your diet. These include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. For this reason, focusing on your intake of essential amino acids (EAAs) is key to meeting your daily requirements.

Calculating your daily essential amino acid needs

Rather than a single, universal daily requirement, the need for amino acids is typically calculated per kilogram (kg) of body weight. The World Health Organization (WHO) provides guidelines for the daily required intake of each EAA for adults. To find your individual need, you can multiply your body weight in kilograms by the recommended amount for each essential amino acid. For example, a 70 kg individual would need 39 mg/kg of leucine, which totals 2,730 mg (2.73 g) of leucine daily. The recommendations are as follows:

Histidine: 10 mg/kg
Isoleucine: 20 mg/kg
Leucine: 39 mg/kg
Lysine: 30 mg/kg
Methionine: 10.4 mg/kg
Phenylalanine (combined with tyrosine): 25 mg/kg
Threonine: 15 mg/kg
Tryptophan: 4 mg/kg
Valine: 26 mg/kg

The role of complete vs. incomplete protein sources

To meet your daily amino acid needs, it's important to understand the concept of complete and incomplete proteins. Complete protein sources contain all nine essential amino acids in sufficient quantities, while incomplete protein sources lack one or more of them. For most people eating a varied diet, combining different incomplete proteins throughout the day is sufficient to provide all essential amino acids.

Complete vs. Incomplete Protein Sources


Feature	Complete Proteins	Incomplete Proteins
Contain all 9 EAAs?	Yes	No, lack one or more
Sources	Meat, poultry, fish, eggs, dairy, soy, quinoa	Nuts, seeds, beans, grains, legumes
Absorption	Generally more easily absorbed and utilized by the body	Must be combined with other sources to create a complete amino acid profile
Dietary Importance	Excellent source for meeting all EAA needs in one food	Requires dietary planning, especially for vegetarian/vegan diets, to ensure a full profile is consumed over time
Examples	Chicken breast, salmon, eggs, Greek yogurt, tofu	Almonds, peanuts, rice, lentils, broccoli

Special considerations for athletes and vegetarians

Athletes and individuals with higher physical activity levels have increased protein and amino acid requirements to support muscle repair, recovery, and growth. For instance, Branch-Chain Amino Acids (BCAAs), which include leucine, isoleucine, and valine, are particularly important for muscle protein synthesis and performance. Athletes may aim for a higher total protein intake, typically ranging from 1.2 to 2.0 grams per kilogram of body weight per day.

For those following a vegetarian or vegan diet, a common concern is the adequacy of essential amino acid intake. While many plant-based foods are incomplete proteins, consuming a variety of different sources throughout the day easily compensates for this. Examples include combining beans with rice, or consuming quinoa, which is a complete protein.

Meeting amino acid needs through whole foods

Meeting your amino acid requirements is best achieved through a balanced diet rich in protein. Whole foods offer a full spectrum of nutrients, not just amino acids, providing a more holistic approach to nutrition. For example, a piece of chicken can provide 55.9g of complete protein, easily meeting and exceeding the daily essential amino acid needs for most individuals.

The role of amino acid supplements

Amino acid supplements are a convenient option for some individuals, such as athletes seeking to optimize muscle recovery or those with specific dietary restrictions. However, for most healthy people, supplements are not necessary to meet daily amino acid needs. It is crucial to consult a healthcare professional or registered dietitian before starting any new supplement regimen, as high levels of certain amino acids can be harmful.

Conclusion

Understanding how many amino acids do I need per day involves considering your individual body weight and activity level, rather than a single, one-size-fits-all number. By focusing on adequate daily protein intake from a variety of sources, including complete proteins from animal products or carefully combined plant-based foods, most people can easily meet their needs. Individual essential amino acid requirements can be calculated using weight-based formulas, but a balanced, protein-rich diet is the most effective and simplest method for overall nutritional health. Consult a healthcare provider for personalized advice, especially if you have high athletic demands or follow a restrictive diet.

Frequently Asked Questions

Essential amino acids are the nine amino acids your body cannot produce on its own and must obtain from your diet. Non-essential amino acids are those that your body can synthesize naturally.

Yes, a well-planned plant-based diet can provide all the necessary essential amino acids. While many plant proteins are incomplete, combining a variety of different sources like legumes, grains, and nuts throughout the day ensures you get a full amino acid profile.

You can calculate your individual requirements by multiplying your body weight in kilograms by the recommended milligram intake for each essential amino acid. For example, for leucine, multiply your weight in kg by 39 mg.

For most people, whole food sources are superior as they provide a complete nutrient package, including vitamins and minerals. Supplements can be beneficial for specific needs, such as for athletes, but should be used under professional guidance.

Yes, due to increased muscle repair and growth demands, athletes and active individuals require a higher intake of protein and amino acids compared to sedentary people. Targeted supplementation may also be useful for athletic performance.

Complete protein sources are the best for a full amino acid profile. These include animal products like meat, poultry, fish, eggs, and dairy, as well as plant-based options like soy and quinoa.

While uncommon for those with a balanced diet, an amino acid deficiency can occur, especially with a highly restrictive or poorly planned diet. It can lead to various health problems like reduced immunity and digestive issues.