Amino Acids: Benefits, Structure & Foods

20 amino acids

Amino acids are often described as the building blocks of protein, and have an important role in a lot of biological processes within the human body. But what are amino acids exactly, and what do they do?

It can be beneficial for anyone and everyone to know a bit more about the inner workings of our bodies and how to keep our nutritional intake at it’s best, which is why OriGym have put together this useful guide. Within it, you can discover the amino acids uses and benefits and where you can find natural food sources of each one. 

Before you read on, if you find learning about nutrition interesting then take a look at our level 4 advanced sports nutrition course - you can turn your passion into valuable qualifications! 

Don’t forget to download our latest course prospectus as well for more information on our courses.

If you’re wondering “what are amino acids used for in the body?” or even “how are amino acids made?” then read on as we’ll answer these questions and more in this guide, with information on the following topics:

What are amino acids?

amino acids protein image

You may know that proteins are what make up the majority of our body parts; muscles, bones, skin, and even our hair. Well, amino acids make up the majority of proteins! 

Proteins are also directly (or indirectly in some cases) responsible for the vast majority of chemical reactions which occur within your body. They are integral to the physical structure of all your cells and they help to form your overall anatomy, from the smallest of internal organs to the size and shape of your arms and legs. 

Amino acids make up proteins, and they are responsible for the type, function, and abundance of proteins produced within the body. In short, they play a large role in maintaining your health. 

When it comes to the essential amino acids, they each have a different part to play within the body, and the symptoms of deficiency can therefore vary greatly for each of them. It’s important for your overall health to consume an adequate amount of each one.

What are amino acids made of?

amino acids structure

Natural amino acids are organic chemical compounds, and they are even thought to be one of the first of their kind to materialize on Earth.  

When it comes to structure, amino acids all have the same basic components: a central carbon molecule bound to 4 other components. Three of these components are the same in all natural amino acids: a single hydrogen molecule (H), an amino group (NH2), and a carboxylic acid group (COOH). 

The 4th component that the central carbon is bound to is called an R group, or side chain. This R group is unique to each individual type of amino acid, and governs its role within your body. 

From identifying these chains we know that there are 20 amino acids, with some variation. These are separated into essential and nonessential groups (this has nothing to do with importance).

There are plenty of sources of protein available these days, including protein popcorn and protein cookies!

How many amino acids are there?

There are 20 amino acids, with 9 essential and 11 nonessential. 

What are essential amino acids?

The amino acids that are classed as essential cannot be synthesised by your body fast enough for the processes that need them, so they must be obtained through your diet instead.  

Children generally need a much higher daily amount of the essential acids than adults, as they contribute to growth and development.

What are conditionally essential amino acids?

A few amino acids are considered to be conditionally essential. These are generally synthesised perfectly adequately within the body.

However, during certain periods of life including adolescent growth, pregnancy, or recovery from trauma, the body struggles to make sufficient quantities of these amino acids. Individuals should aim to obtain extra through dietary sources to ensure the body functions properly. 

The conditionally essential amino acids are: Arginine, Histidine, Cysteine, Glycine, Tyrosine, Glutamine and Proline. 

What are nonessential amino acids?

The nonessential amino acids are synthesised within your body, meaning that there is no need (apart from in exceptional circumstances) to gather additional quantities of these amino acids through your diet. 

If nutrition is something that interests you then you should look into how to become a nutrionist, or even a sports nutritionist here!

What are branched chain amino acids?

what are the benefits of amino acids

Branched chain amino acids (BCAAs) are essential amino acids but with a slightly different structure. 

They have branched side chains which means they can be digested by the body much quicker than other types of amino acids as BCAAs aren’t processed through the liver and instead are absorbed straight into the bloodstream.  

Branched chain amino acids benefits are also slightly different: due to the faster metabolic rate BCAAs can provide an energy boost, as well as promoting faster synthesis of muscle proteins. So, if you were wondering “what are the best amino acids for muscle growth?” then BCAA amino acids are definitely some of the ones you should be looking at.

There are 3 BCAAs from the essential amino acids list, which are: leucine, isoleucine, and valine. 

For some great supplements check out our list of the 13 best BCAA tablets.

What are the 9 essential amino acids?

list of amino acids

Of the 20 amino acids, 9 are considered to be essential. They are: Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Leucine and Lysine. 

The reasoning behind the body being able to synthesise some and not others is an evolutionary one. Synthesising amino acids requires a biosynthetic pathway (a map within your body) to be in place in order to guide the formation of each amino acid. 

These pathways demand energy in order to function, so by removing some of these pathways the body can conserve energy for other internal processes that are more crucial to keep functioning at optimal levels. 

9 pathways were removed over time through evolution, due to the abundance of these 9 particular natural amino acids in nutritional sources available to humans in the environment. Why should your body expend energy by carefully making something, when it can easily be incorporated through everyday processes such as eating?

Check out the pros and cons of being a nutritionist to see if this is the right career for you!

So, what are these amino acids used for?

amino acids side effects

Well, almost everything! But to be more precise, let’s have a look at the 9 essential amino acids in more detail.

1. Phenylalanine

This is one of the amino acids for anxiety and depression as it is a precursor for neurotransmitters such as dopamine and tyrosine, adrenaline and noradrenaline. Due to its effect on specific neurotransmitters, Phenylalanine is used in modern medicines as an antidepressant.

It is also involved in the structure of various proteins and enzymes, helping to produce other amino acids within the body. 

Found in plant and animal sources: seeds such as pumpkin seeds, soy, eggs, seafood.

2. Valine

One of the BCAAs (branched chain amino acids) which is in reference to its chemical structure. 

Although one of the least significant BCAAs for the body, valine is a popular supplement for gym goers due to its involvement with muscular growth and regeneration, and energy provision for the body.

Natural sources include dairy products, meat, soy, beans, quinoa.

3. Tryptophan

what are the 20 amino acids

This amino acid is important in the regulation of nitrogen within the body and also acts as a precursor to the neurotransmitter, serotonin, which regulates sleep, mood and appetite, so is one of the more important amino acids for depression and mood treatments.

It is also a precursor to the hormone melatonin, and is key to the structure of cells. 

Can be found in natural sources such as chicken, fish, cheese, eggs, milk, seeds and more.

4. Threonine

Involved in the function of your immune system, as well as metabolising fats. 

Its key function is structural, helping support elastin and collagen, which are components of connective tissues and your skin. 

Natural sources include fish, cheese, poultry, lentils.

5. Isoleucine

Another of the commonly supplemented BCAAs. 

As well as its role in muscular development, it also helps to regulate energy balance in the body and contributes to the production of haemoglobin, and the function of the immune system. 

Sources include eggs, seaweed, meat (such as chicken, lamb) fish, cheese.

6. Methionine

Helps the body to absorb minerals, such as zinc and selenium, which are important for your body’s health and function. 

Furthermore, Methionine is involved in the growth of tissues, and is also involved in metabolism and detoxification. 

Foods with higher levels of methionine include eggs, some meat, and fish.

7. Histidine

Vitally important in the maintenance of the internal barrier which protects your nerve cells, the myelin sheath. 

As well as this, Histidine is involved in the production of histamine (think antihistamine tablets for allergies), which plays a key role in your immune system. Also playing a role in your sleep-wake cycle, digestion and sexual function. 

Sources include meat, fish, nuts, seeds.

8. Leucine

what are amino acids good for

The 3rd of the BCAAs critically involved in muscle growth and repair; sometimes referred to as the primary or main BCAA due to its properties. 

As well as this, it helps regulate blood sugar, and encourages the healing process. 

Food sources include meat, dairy, fish.

9. Lysine

Like Threonine, this amino acid supports the production of collagen and elastin. 

Lysine also involves itself in hormones, enzymes and calcium regulation. Fatigue, hair loss, anemia, and red eyes are just a few of the symptoms of a lack of Lysine in the body. 

Sources include fish, eggs, dairy products, meat.

One natural and tasty source of these amino acids is coconut water! Find out more about the other benefits, uses and nutritional information of coconut water here.

Each one of these 9 essential amino acids must be present in your diet to ensure that your body can properly perform each of these critical roles and more. 

From only 20 amino acids, your body is able to synthesise around 20,000 unique proteins which are then involved in almost every process in your body, from neurotransmissions to the growth of skeletal muscle. 

Lacking in any amino acid brings about serious complications. These include, but are by no means limited to: 

  • Depression
  • Anxiety 
  • Insomnia 
  • Fatigue 
  • Muscle weakness 
  • Physical stunting

These deficiencies are often noted in less economically developed parts of the world where a complete diet is not freely available, and also within elderly adults who may not have the supportive care that they require.

What are the 11 nonessential amino acids?

what are the 11 non essential amino acids image

Alongside the 9 essential amino acids, there are also 11 nonessential amino acids that are produced by the body and are needed for the synthesis of protein. These are: Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic Acid, Glutamine, Glycine, Proline, Serine, and Tyrosine.

The word ‘nonessential’ can be deceiving, as these amino acids are still crucial to a variety of biological processes: in this sense it just means that the body naturally produces nonessential amino acids.

The nonessential amino acids list includes:

1. Alanine: 

This is crucial to the building of protein and cell walls, and is formed when carbohydrates are broken down by the body. Beta-alanine has more benefits, side effects, and uses so read our article for more on what they are!

2. Arginine:

what are the best amino acids for muscle growth

This amino acid is key to the regulation and maintenance of hormone levels within the body, and also plays a role in stimulating the growth hormone and in wound healing. For more information on this amino acid read our guide on l-arginine here.

3. Asparagine:

Once again, a key component to the synthesis of protein, as well as being a diuretic (a substance that removes water and salt from the body). It’s named after Asparagus, which was the first place it was found!

4. Aspartic acid:

This amino acid is hugely important in the synthesis of the majority of the other amino acids, including methionine, arginine, lysine, asparagine and isoleucine.

5. Cysteine:

This one is crucial to the creation of collagen, and is one of the main amino acids for hair, nails, and skin.

6. Glutamic acid:

This amino acid is an essential neurotransmitter needed in the nervous system. It is often confused with glutamine, however the two amino acids are not the same compound.

7. Glutamine:

Glutamine is a derivative of glutamic acid. It’s important for the immune system and plays a fundamental part in keeping the intestinal system healthy. We have an article on l-glutamine's benefits, side effects and dosage so read more about this amino acid there.

8. Glycine:

what are amino acids used for in the body

Necessary for building protein, as well as being a component in creatine (a compound in the body which provides energy to muscles) and in collagen.

9. Proline

This amino acid is involved in the synthesis of collagen, as well as the maintenance of cells and the healing of skin.

10. Serine:

Serine is another precursor to a number of amino acids, which is a key component of brain cells.

11. Tyrosine

This one is key to the production of neurotransmitters, as well as hormones such as dopamine and adrenaline.

These amino acids are also produced within the body, while most can also be found in food sources too. Some were actually named after the food sources they were found in, like Tyrosine, as ‘tyro’ means cheese in Greek!

Overall amino acid function is dependent on availability within the body, the more the better, or perhaps it’s more accurate to say the fewer the worse, as there is a ceiling to the benefits. 

What are the benefits of amino acids?

Whilst you may not consider the majority of the previous bodily functions as benefits per say, there are a few processes that are significantly more advantageous to our health. Let’s take a look at some of these benefits that are more commonly attributed to sufficient amino acid intake.

#1 - Increased Muscle Growth

amino acids uses

One of the most commonly sought after goals of people who supplement sources of amino acids is to increase muscle mass. 

Whilst you’re probably getting enough of these amino acids from your diet - they’re found in natural sources such as eggs, chicken, fish - BCAA supplements are now a staple in the majority of gyms and fitness centres.

As discussed previously, amino acids are responsible for the growth and development of skeletal muscle, in particular, BCAAs. These amino acids serve as precursors to muscle protein synthesis and also play a role in reducing the initiation rate of the translation steps of muscle protein synthesis. 

Ensuring sufficient quantities of BCAAs in your diet is definitely essential if you’re looking to maximise your training results, with studies showing that people who consume a BCAA supplement after resistance training have up to 22% increase in muscle synthesis (compared to control groups). 

Some people find that taking supplements before a workout is the most optimal time: look at OriGym's article for some of the best pre-workout supplements.

Whilst taking BCAA amino acids supplements as well as having a balanced diet can mean you’re intaking higher levels of amino acids than you need, this won’t have any particularly dangerous side effects. It just means that the excess amino acids will ultimately be wasted.

#2 - Decreased Fatigue

20 amino acids

Just as amino acids are essential for muscle development, they are also essential for cognitive function. Having low levels of amino acids in the blood can trigger a response from the brain to slow physical activity and rest in order to conserve the amino acids you do have and maintain your mental awareness. 

This can be seen particularly clearly after intense exercise where an increased quantity of amino acids has been recruited for your muscular endeavours. 

Maintaining a diet high in amino acids helps to ensure that you can supply all areas of your body at all times, helping to reduce feelings of fatigue whilst still enabling intense physical activity.

With multiple amino acids being key neurotransmitters and precursors for hormones such as dopamine and serotonin (which are key to sleep patterns), ensuring that your intake is sufficient will ensure that these bodily functions work properly.

Similarly, serotonin is one of the key chemicals in signaling fatigue to the body. By taking BCAA supplements the blood levels of serotonin are reduced, meaning that the symptoms of fatigue are lessened.

Another option for decreased fatigue is one of our top vitamins for energy!

#3 - Improved Recovery Time

structure of amino acids

Due to the nature of amino acids function within the body, ensuring your diet is complete is paramount to muscle repair and recovery. 

When you train for muscle development, you will often experience muscle soreness afterwards: this is a result of tiny tears in the muscle fibres which require repair. The repairing of the fibres results in muscle growth. 

These tears cannot be repaired as efficiently if you are lacking in amino acids. Studies have found reduced muscle soreness and improved recovery times in subjects who have an abundance of amino acids in their diet. 

One particular study in the Journal of Nutrition stated:

“When BCAAs are ingested during endurance exercise, either running or standardized ergometer cycle exercise, the results indicate that the BCAAs have an effect in the recovery period after exercise rather than during the actual exercise. This conclusion is based on indirect measurements of protein metabolism (i.e., the release of tyrosine and phenylalanine from the muscle along with the change in the muscle concentration of these amino acids).”(Blomstrand et al., 2006)

The benefits of BCAA amino acids therefore extend to aiding recovery by further stimulating muscle synthesis. The study tested this hypothesis in various training methods, with results being similar across different practices:

“Similar to the results from resistance exercise, ingestion of protein directly after endurance exercise stimulated protein synthesis in the recovery period and a positive leg protein balance was found, as measured by the stable isotope technique.”(Blomstrand et al., 2006)

This is beneficial as faster recovery times means you can get back to training faster and even with more intensity.

For another natural source that can help reduce your recovery times, check out our article on the 17 benefits of blueberries!

#4 - Prevents Muscle Wastage 

benefits of amino acids

In the same way you can get amino acids from your diet, your body can take them from your muscles. 

By breaking down muscle the body retakes some of the amino acids it requires for more important functions such as brain activity. Muscle wastage can occur as a result of malnutrition or disease; it also occurs as a result of the natural aging process. 

If you are lacking in amino acids, your muscles are the first thing to be broken down. To avoid this you can provide your body with a healthy and balanced diet containing all the amino acids your body may be substituting from your muscles. 

Many scientific studies support amino acid supplementation for people living with diseases which cause muscle wastage and for people who are unable to obtain a fully nutritious diet. One study in the British Journal of Nutrition stated that:

“Specifically in cancer patients, stimulated muscle protein synthesis has been obtained by increasing the amount of protein in a meal and by providing additional leucine. Also in other chronic diseases such as chronic obstructive pulmonary disease and cystic fibrosis, meals with specific dietary proteins and specific combinations of dietary essential amino acids are able to stimulate anabolism.” (Jonker, Engelen and Deutz, 2012)

This basically means that increasing amino acid intake can actually be beneficial to those suffering from diseases such as cancer, as the wastage of the muscles can be reduced.

More generally, should you wish to increase your intake more than you are able through your daily diet you can choose from a variety of options; one of the best being whey protein, whilst more general amino acids supplements are also available. 

#5 - Supports The Immune System

what are the functions of amino acids in the body

Amino acids are also hugely beneficial to the immune system, which means that you’ll be less likely to become ill from colds and illnesses, and you’ll also heal from wounds or infections much quicker.

Another supplement that will boost your general health is pea protein.

This happens through a number of processes. Firstly, amino acids are key to the transportation of nutrients and energy around the body. This contributes to the healing and repair of skin and muscles. Additionally, amino acids contribute to the production of immunoglobulins - or antibodies - which are essential to fighting off infections and disease.

The effects of amino acids on the immune system are discussed in the Journal of Nutrition, which stated:

“Thus, it is possible that an enhanced supply of key amino acids in certain clinical settings will improve patient outcomes. There has been great interest in the effect of amino acids on immune function. However, this interest has centered largely upon glutamine (3–6), arginine (7–9), and, to a lesser extent, sulfur-containing amino acids, whereas much less is known about the impact of changes in BCAA availability on the ability of the immune system to function.” (Calder, 2006)

This basically means that amino acids are often supplemented in patients suffering from severe illnesses due to the immune boosting properties.

What foods are essential amino acids found in?

amino acids in food image

A balanced and nutritious diet is often a sufficient technique to ensure you are getting all the essential amino acids that your body requires, with complete proteins providing all variants in one go. 

Complete proteins are usually derived from animal-based sources, such as eggs and egg white, with soy being a notable exception. 

Don’t panic if you choose not to consume animal products, a careful combination of incomplete proteins can offer the variety and quantity of amino acids that you need. 

Incomplete proteins are generally plant-based and more appealing to a universal audience. They are, however, often made up of limiting amino acids: this refers to those which are present but in short supply within the food, and do not constitute the requirements for complete human nutrition. 

If you do choose to make up your diet without animal products, be aware that you may have to spend a little more time and effort to achieve a balanced and effective supply of complete nutrition. 

If you believe your foods high in amino acids intake may be lacking you can supplement your intake from a variety of sources, many available from supermarkets, health shops and fitness brands. There have been huge quantities of studies into the benefits of amino acids supplements, generally with positive results. 

As previously stated, amino acids are readily available from a carefully balanced diet containing sources of protein, with the best amino acids in food being animal derived, such as beef, chicken, eggs and fish. 

If you don't eat meat or animal products then you can still obtain amino acids from your diet, including a variety of foods such as nuts, seeds, grains and legumes as well as tofu, seitan and soy products. 

What foods are high in amino acids?

foods rich in amino acids image

If you’re unsure of the best options available for foods rich in amino acids, here are some of the best sources available:


Eggs contain all of the essential amino acids, making them a complete protein

The nutrients from eggs are also readily absorbed throughout your digestive tract ensuring you can get the most out of them if you choose to consume them as part of a balanced diet. If you’re looking for foods high in amino acids for muscle building then eggs are a great option!

Red meat: 

Providing complete proteins, no limiting amino acids and all the essential amino acids you require, red meat (such as beef) is one of the richest sources of amino acids protein available.


Although not in the same concentrations as red meat, poultry (such as chicken and turkey) also provides all the essential amino acids and is a good source of complete proteins. 

It’s also considered one of the best sources of natural amino acids for muscle building.


Just like poultry and red meat, fish is considered a complete protein and one of the healthier foods that contain amino acids. 

High in all essential amino acids and offering the added benefit of omega-3 which is linked to a healthy heart, healthy digestion, healthy skin and eyes and more. 

Oily fish should be consumed 2 times a week: if you don’t eat any oily fish you should consider supplementing with fish oil or cod liver oil


Yoghurt made from animal milk is also a source of amino acids and acts as a source of complete protein. Although lower in concentrations than meat options, yoghurt is still a great source and easily consumed as a snack throughout the day.

foods containing amino acids image

Don’t panic if you avoid animal products, there are foods containing amino acids out there for vegetarians and vegans too:


Containing all 9 essential amino acids, quinoa is a whole grain that provides complete protein. 

Although not as high in natural amino acids or protein as its animal counterparts, quinoa can also be a great source of dietary fibre, something a lot of us are lacking in.


Soybean products are also a complete, non-animal protein. Soy products include, tofu, tempeh and edamame, and all provide complete protein with all 9 essential amino acids. 


Wheat gluten provides a meat-free source of protein, however, it is not a complete protein as it has low levels of lysine and should be consumed as part of a mixed meat-free diet to ensure you get all of the essential amino acids. 


Mushrooms are also excellent sources of protein and provide all the natural amino acids benefits the human body needs. 

They actually contain all 9 essential amino acids, unfortunately methionine and phenylalanine are not present in high enough concentrations to make mushrooms a source of complete protein though.

Another plant that is worth incorporating into your diet is the eggplant: find out about the eggplant's health benefits and uses now!

Nuts and seeds: 

A great option for easy snacks through the day as well as being sources of protein and natural amino acids. 

Again, like many non-meat sources, they are not a complete protein, lacking in lysine. 

What amino acids are in whey protein?

amino acids for muscle image

Whey protein is one of the best amino acids supplements. It contains all the essential amino acids your body needs, encouraging muscle synthesis and supporting healthy bodily functions. 

Take a look at OriGym's cheap whey protein powders here to get all the amino acids you need without as much expense.

It is not surprising that whey protein shakes are one of the most popular forms of workout supplements, and can also be supplemented as amino acids for weight loss support. 

There are vegan protein shakes and powders available too, although soy protein is generally the only available complete protein version; as a result if you are using vegan powders you should consider using a mixture and checking the number of amino acids to maximise your results and health. 

It is generally recommended that you attempt to maximise the nutrition you obtain from your daily meals, as this is the best way to ensure you provide your body with all the nutritious vitamins and minerals that you need for a healthy life. 

Planning and optimising your diet also helps to make sure that you aren’t detracting from other aspects of your nutrition by focussing too much on one thing, and ensures you’ll be getting all of the benefits of amino acids. 

What are the side effects of amino acids?

what are amino acids

Whilst overconsumption of protein (that contains amino acids) doesn’t have any direct negative impacts on your health, your body will utilise what it can and “waste” the rest. 

If you consume too many of your daily calories through protein or amino acids supplements you are then in danger of negatively impacting your nutritional diversity and missing out on benefits from sources not included in the supplements.

Make sure you get only as much protein as you need, and then focus on incorporating the right amounts of other nutrients. 

One common question often asked about nutrition is can personal trainers give nutritional advice? Our article has the answers!

The function of amino acids varies massively within the body, so there isn’t one tell tale symptom or side effect that signals that you may be amino acid deficient, but rather individual signs which may point towards a deficiency in one or more of the essential amino acids. These amino acids side effects can include:


A deficiency in phenylalanine can result in behavioural issues, eczema and vomiting. 

This may be a result of a defective gene, causing phenylketonuria (PKU). Roughly 1 in 10,000 people suffer from PKU: they cannot break down phenylalanine or absorb it into the body which can result in a dangerous build up in the blood, eventually leading to brain damage. PKU is tested in babies at around 5 days old, it will present early in life if not caught. 

Contact a medical professional immediately if you are concerned about the possibility of PKU, with early diagnosis and treatment people with PKU can live a normal life with dietary intervention.


what are the amino acids

Playing a role in energy regulation can lead to deficiency being seen through reduced mental awareness and irregular sleep patterns. 


Due to the role it plays in mood regulation, deficiency can often display as increased pain sensitivity, being easily startled and aggression.


Deficiency can present itself through unhealthy looking skin and teeth; some animal studies have shown reduced resistance to disease.


Low levels of isoleucine can be associated with muscle wastage and tremors due to increased weakness, often more apparent in older people. 


what are the biological functions of amino acids

Low levels of methionine can become apparent in a variety of ways, including, abnormal muscle contractions, tremors, headaches, abnormal eye movements and problems with psychomotor development and intelligence.


As it plays a part in haemoglobin production, deficiency can present as anaemia. 


Deficiency is often linked to unhealthy hair, tiredness and unhealthy-looking skin, including rashes.


Levels of stress and anxiety may increase with low concentrations of lysine due to its role in hormonal production levels. Additionally, anaemia, lack of connective tissues, and reduced metabolism can also occur.

This list of amino acids' side effects is not exhaustive, signs and symptoms given here can differ subjectively and may also be linked to other medical issues. If you are concerned about your health, contact a medical professional.

Essential and nonessential amino acids are involved in almost all biological processes involved within the body, from thinking, to fighting off illness, to building and repairing muscle mass; 20 tiny chemical compounds which play a part in every action you do, consciously and subconsciously! 

Making sure you consume sufficient quantities of amino acids is guaranteed to promote a healthy and active life. If you struggle to maintain a balanced nutritious diet then you should most definitely look for supplementary sources.

Amino Acids Recommended Daily Intake

what are the 9 essential amino acids

The following amounts are the average WHO (World Health Organisation) recommended daily intakes of mg per kg of bodyweight for amino acids (essential):

  • Phenylalanine: 25mg
  • Valine: 26mg
  • Tryptophan: 4mg
  • Threonine: 15mg
  • Isoleucine: 20mg
  • Methionine (plus nonessential cysteine): 15mg
  • Histidine: 10mg
  • Leucine: 39mg
  • Lysine: 30mg

Consuming complete proteins (which we discussed earlier in the foods sections) will mean you’ll be more than likely to get sufficient amounts of these amino acids just through your diet, meaning you shouldn’t need to supplement.

For example, an 85g serving of chicken (which is a complete protein, containing all of the essential amino acids) would provide roughly 1500-2000mg of Lysine, 600-700mg of Histidine, and around 100-250mg of Tryptophan. These amounts are already more than the necessary daily intake.

Mushrooms are also a great source of complete proteins that are even said to contain almost as much protein as meat sources!


If you were wondering “why are amino acids important?” then hopefully this guide has given you the answers! They’re not just the building blocks of proteins, they contribute to a vast majority of biological functions in the human body and are crucial to nutritional benefits. 

Has learning about nutrition and health grabbed your interest? Why not study with us and achieve your level 4 advanced sports nutrition qualification! Download our free course prospectus as well to find out more about our diplomas and courses.


  1. Blomstrand, E., Eliasson, J., Karlsson, H.K.R. and Köhnke, R. (2006). Branched-Chain Amino Acids Activate Key Enzymes in Protein Synthesis after Physical Exercise. The Journal of Nutrition, 136(1), pp.269S-273S.
  2. Børsheim, E., Bui, Q.-U.T., Tissier, S., Kobayashi, H., Ferrando, A.A. and Wolfe, R.R. (2008). Effect of Amino Acid Supplementation on Muscle mass, Strength and Physical Function in Elderly. Clinical Nutrition, 27(2), pp.189–195.
  3. Calder, P.C. (2006). Branched-Chain Amino Acids and Immunity. The Journal of Nutrition, 136(1), pp.288S-293S.
  4. Jonker, R., Engelen, M.P.K.J. and Deutz, N.E.P. (2012). Role of Specific Dietary Amino Acids in Clinical Conditions. British Journal of Nutrition, 108(S2), pp.S139–S148.

Written by Dee Hammond-Blackburn

Fitness Content Executive, OriGym

Join Dee on Facebook at the OriGym Facebook Group

Dee holds a BA (Hons) in English Literature, and is currently finishing her MA in Marketing Communications and Branding from Edge Hill University. Her passion for fitness and content writing brought her to OriGym, and she has since become a qualified Personal Trainer and a Sports Nutrition Specialist. Combining her skills in fitness and writing, Dee has a professional interest in fitness blogging, content creation, and social media. Outside of her writing role Dee enjoys reading, healthy cooking, and playing football with her dalmation.

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