Triglycerides, or triacylglycerols, are the main storage form of fats within the body. They are predominantly found as solids in peripheral adipocytes and circulate in all the subtypes of lipoprotein carrier.
They consist of a glycerol molecule conjugated to 3 fatty acid molecules.
Triglycerides are primarily an energy source; they liberate the largest amount of energy per unit mass of any of the fuel sources.
A lean adult has 15kg of triglyceride (which yields about 38 kilojoules for each gram respired - it thus represents an energy store of 570,000 kilojoules - this is approximately enough energy to survive for 3 months).
The adipose tissue in which triglyceride is stored performs various roles:
Triglycerides are digested in the gut to fatty acids and monoglycerides. These are in turn absorbed into the enterocytes and chylomicrons are synthesized for transport to the tissues. The liver is also able to synthesize triglycerides using fatty acids (either from the circulation or synthesized from glucose). The liver assembles triglycerides within the very low density lipoproteins (VLDL) which are released into the circulation.
Deriving fatty acids from adipose tissue stores:
Last reviewed 03/2021