Facts about Fat

Consumption of saturated fats, which are common in some dairy products (such as butter), meat, and poultry, correlates with heart disease, stroke, and even some cancers.

Concentrated fat deposits in adipose tissue insulate organs against shock and help to maintain a stable body temperature.

Chemically speaking, fats are triglycerides, uncharged esters of the three-carbon alcohol glycerol that are solid at room temperature (20° C).

The consumption of fats in the diet requires personal responsibility and discipline, as there is diversity in the health impacts of different triglycerides.

The hormone glucagon signals the breakdown of the triglycerides by hormone-sensitive lipases to release free fatty acids.

The triglycerides are rebuilt in the blood from their fragments and become constituents of lipoproteins, which deliver the fatty acids to and from adipocytes.

Fatty acid chains in naturally occurring triglycerides are typically unbranched and range from 14 to 24 carbon atoms, with 16- and 18-carbon lengths being the most common.

The fat deposits collected in adipose tissue can also serve to cushion organs against shock, and layers under the skin (called subcutaneous fat) can help to maintain body temperature.

Triglycerides consist of three fatty acid chains bonded to a glycerol backbone.

A triglyceride is an ester of glycerol; i.e., a molecule formed from a condensation (water-releasing) reaction between the three hydroxyl (-OH) groups of glycerol and the carboxyl groups of the three fatty acid molecules.

Fatty acids are distinguished by two important characteristics: (1) chain length and (2) degree of unsaturation.

Consequently, ruminant animal fat, such as in cattle, contains significant proportions of branched-chain fatty acids, due to the action of bacteria in the rumen.

The double bonds in unsaturated fatty acids may occur either in a cis or trans isomer, depending on the geometry of the double bond.

Fatty acids found in plants and animals are usually composed of an even number of carbon atoms, due to the biosynthetic process in these organisms.

Bacteria, however, possess the ability to synthesize odd- and branched-chain fatty acids.

Fatty acids with long chains are more susceptible to intermolecular forces of attraction (in this case, van der Waals forces), raising their melting point.

The class of fat-soluble vitamins—namely, Vitamins A, D, E, and K—can only be digested, absorbed, and transported in conjunction with fat molecules.

The chemical properties of triglycerides are thus determined by their particular fatty acid components.

A diet with vegetable oils, fatty fish (such as salmon), and nuts are important in this respect.

In animals, a type of loose connective tissue called adipose contains adipocytes, specialized cells that form and store droplets of fat.

Fat-soluble vitamins are involved in activities ranging from blood clotting to bone formation and can only be digested and transported when bonded to triglycerides.

When energy is needed, stored triglycerides are broken down to release glucose and free fatty acids.

Fatty acids are a class of compounds that consist of a long hydrocarbon chain and a terminal carboxyl group (-COOH).