|  | Diet Nutrition | Nutrition

What Are Fats & Lipids?

Fats and other lipids have been painted as the dietary villains of our society. New diet fads come out seemingly every month touting greater fat-trimming power than the last trend. What some may not know is that these biomolecules are absolutely essential components of healthy nutrition.

  1. Features

    • Lipids are composed of fatty acids, which are organic carboxylic acids that have long hydrocarbon chains. These biomolecules are diverse in form and function. Common fatty acids are between 12 and 24 carbon atoms in size. They can be saturated, in which no double bonds exist in the chain, or unsaturated, in which one or more double bonds put a "kink" in the chain.

    Types

    • Lipids are classified based on the organization of fatty acids, prosthetic groups and scaffold molecules. The first group is triglycerides, or fat molecules. These contain three fatty acid chains linked to a glycerol molecule. The second group is phospholipids, which only have two fatty acids connected to a glycerol molecule. The third hydroxyl group of glycerol is linked to a phosphoryl group, which can then be further modified with nitrogenous or carbohydrate prosthetic molecules. Sphingolipids are similar to phospholipids. except that ceramide is the scaffold as opposed to glycerol. The final class of lipids consists of the steroid cholesterol and its derivatives.

    Functions

    • Triglycerides are used for long-term energy storage by mammals, and in human bodies, they make up goblet cells filled with fats, which are mainly found in the gut region. Triglycerides are utilized during glucose starvation. Phospholipids, due to their amphipathic nature, are major components of the plasma membrane found around all living cells. Plasma membranes are natural barriers against unwanted biomolecules. Sphingolipids and cholesterol are more complex components of the plasma membrane; the latter is also used to produce steroid hormones.

    Dietary Considerations

    • Mammalian species require a certain amount of lipid intake for two main reasons. Animals in polar climates must be able to withstand bitterly cold temperatures, and large quantities of fat in the form of blubber handles this need quite well. Lipids are also necessary for the upkeep of our long-term energy stores for use during periods of starvation. Also, if we do not intake certain fatty acids which our bodies do not synthesize--the essential fatty acids like DHA--poor growth can result. Even cholesterol is necessary in small amounts; deficiency can lead to increased risk of stroke.

    Warnings

    • There are also dangers and risks associated with too much intake of lipids and fats. Obesity is the most obvious result of excess dietary fats, but a secondary effect of obesity is an increased risk of diabetes. Excess cholesterol--and some lipids--can cause cardiovascular problems such as plaque buildup.

Nutrition - Related Articles