Proteins

Proteins are made up of 20 different amino acids, some of which are synthesized within the body (non-essential) while some are not synthesized in the body (essential amino acids).

Our body can make 11 on its own but the other 9 essential amino acids have to come from food because your body lacks the genetic code to synthesize them from scratch. You must eat them to survive.

The most famous and easiest way to remember all nine is the phrase:

"PVT TIM HALL"

(Read as: Private Tim Hall)

Letter	Amino Acid	Memory Hook/Function
P	Phenylalanine	Think "Phone" — used for brain signaling (dopamine).
V	Valine	A "Branch-Chain" (BCAA) for muscle growth.
T	Threonine	Think "Thread" — helps make collagen/connective tissue.
T	Tryptophan	The "Turkey" chemical — makes serotonin and melatonin.
I	Isoleucine	Another BCAA — critical for immune function.
M	Methionine	Think "Metabolism" — contains sulfur; helps skin/hair.
H	Histidine	Think "Histamine" — vital for your immune response.
A	Arginine*	Note: Often essential only for children, but usually included.
L	Leucine	The "King" of BCAAs — triggers muscle protein synthesis.
L	Lysine	Crucial for calcium absorption and bone health.

Categories:

• "BCAAs" (Branched-Chain Amino Acids) are the primary builders of muscle tissue - Leucine, Isoleucine, and Valine.
• "Aromatics" have a ring structure and are mostly responsible for your mood and brain function - Phenylalanine and Tryptophan.

Food Sources:

• Animal proteins (meat, eggs, dairy) are "Complete"—they contain all 9 in the right proportions.
• Plant proteins are often "Incomplete" (missing one or two). For example, grains are usually low in Lysine, and legumes are low in Methionine. This is why "Rice and Beans" is a classic combo; they complete each other's amino acid profiles.

Histidine was once thought to be essential only for infants. Modern science confirms it is essential for adults too.