Dietary guidelines : fats (saturated and unsaturated)

Our body stores energy as glycogen (short term storage) and fat (long term storage). Fat is an efficient, lightweight, flexible, and portable source of energy. 

A saturated fatty acid contains single bonds between the carbon atoms.  A “saturated” fatty acid has the most hydrogen atoms it can possibly carry—it is therefore “saturated” with hydrogen. Every carbon atom is attached to as many hydrogen atoms as it can hold. Each carbon-hydrogen bond carries energy, so the more hydrogen atoms that are bound to a fat, the more energy you can get out of that fat when you burn it. Saturated fat has more energy, and therefore more calories, per pound.

Saturated fats, with their full load of energy-packed hydrogen bonds, are straight molecules that pack together efficiently, and are therefore solid at room temperature. Unsaturated fats, with their weaker double bonds, are crooked, because double bonds create kinks in the backbone. When molecules have room to move around easily, they are more likely to form liquids than solids.

Most fats occurring in nature contain mixtures of saturated, monounsaturated, and polyunsaturated fatty acids. Olive oil contains approximately 17% saturated fatty acids, 71% MUFA (oleic acid), and 11% PUFA’s. Coconut oil contains more than 90% saturated fat. Beef fat contains nearly equal parts saturated fat and monounsaturated fat (most of which is oleic acid, the primary fatty acid in olive oil) and approximately 5% polyunsaturated fat, depending on what the animal is fed.

Saturated fats are very stable, whereas unsaturated fats (oils) are fragile. The carbon double bonds in unsaturated fats are weak and vulnerable to chemical attack compared to the strong carbon-hydrogen bonds in saturated fats. This is why unsaturated fats (oils) go rancid (become “oxidized”) when exposed to air, whereas you can leave lard or butter on the countertop for a long time without worrying about it. Ghee, which is butter with all of its proteins removed (pure butterfat), can be stored at room temperature indefinitely.

Saturated fat is the preferred fuel of the heart, which is why the heart has some saturated fat wrapped around it.

Saturated fats are good for things like insulation (myelin), cushioning (abdominal fat around our organs), and storage (body fat under the skin) purposes.

An unsaturated fatty acid contains double bonds between the carbon atoms and have less hydrogen.   Monounsaturated means it contains one double bond.   Polyunsaturated means it contains more than one double bond.

If a carbon atom does not have a hydrogen to bond to it forms a double bond with a carbon atom.  If a fat atom has one double bond, it is called “monounsaturated” (missing one hydrogen).

A monounsaturated fatty acid (MUFA) is oleic acid found in olive oil.

A polyunsaturated” fatty acid has more than one double bond. It is missing more than one hydrogen.

Unsaturated fats are good for flexibility and fluidity purposes, such as in membranes and body fluids.