Amino acids

Protein is made up of a chain of amino acids. There are 20 amino acids and they can be classified into three groups:

• Essential
• Non-essential
• Conditionally essential

Essential amino acids

They are called essential because they cannot be made by the body and so we must get them from food.
There are 9 amino acids in this list, but one of them, histidine, is only essential for infants, not adults.

• histidine (for infants, not essential for adults)
• isoleucine
• leucine
• lysine
• methionine
• phenylalanine
• threonine
• tryptophan
• valine

Non-essential amino acids

Our bodies produce these amino acids, so they are not ‘essential’ in our diet.

• alanine
• asparagine
• aspartic acid
• glutamic acid

Conditionally essential amino acids

These are not usually needed from food, unless stress, sickness or disease is present.

• arginine
• cysteine
• glutamine
• tyrosine
• glycine
• proline
• serine
• ornithine

Protein

What is protein?

How much protein do we need?

Examples of plant based protein meals

Plant-based protein & athletes

Protein FAQs