Lipids is the name given to a group of molecules that are naturally occurring. This group includes fats, waxes, fat-soluble vitamins such as A, D, E and K, sterols, monoglycerides, diglycerides, triglycerides and phospholipids. Whilst many essential lipids can be made by the human body, some need to be obtained from food and beverages. The main function of lipids is the storage of energy within the body. Lipids also carry out a number of other functions such as vitamin absorption, energy production, cell lubrication, hormone production and play a role in sending signals throughout the body.
How are lipids stored in the body?
Lipids are stored in a number of different ways within the body. The body stores lipids so that they can be easily used within the body when needed. When ingested lipids travel in the blood stream, but are not dissolved by blood because they are not water soluble. The liver produces specialized proteins called lipoproteins to temporarily store and transport lipids in the blood stream. The lipids are either used within the body or are absorbed into the liver where they are released at a later time to provide cellular energy when needed. Bad cholesterol is also broken down by the liver into bile acids. Lipids are most commonly converted into triglycerides for later use. Some triglycerides remain in blood stream and some are stored in fat cells. Excess lipids in the blood are converted into adipose tissue (fat cells) which stores the lipids until needed and this is where fatty acids are stored for later use.
Some lipids are not stored at all and are used to make brain and nerve tissue, excreted via the elimination system, oxidized for energy, or used to create cell membranes.