Saturated fats are found principally in animal products, but also in coconut and palm oils.
The term saturated means that all of the carbon atoms in the long chains of these fats, often described as the carbon backbone, are connected to each other with single bonds. When the carbon chains of these fats have all the hydrogen atoms they can hold, they are said to be saturated with hydrogen.
These fats have high melting points and so are typically solid or nearly solid at room temperature (except for coconut and palm oils). This is critical to understanding the saturated fat MS connection.
If one double bond is present between any two carbon atoms in a fat, that fat is monounsaturated. A typical example is oleic acid in olive oil.
These fats have lower melting points and so are liquid at room temperature, but will solidify a little or go cloudy in the fridge.
Monounsaturated fats are sometimes called omega-9 fats because the only double bond present in the backbone is at the ninth carbon from the omega end.
If more than one double bond is present, the fat is polyunsaturated.
These fats have the lowest melting points and are liquid at room temperature and in the fridge. Many of these polyunsaturated fatty acids are what we call essential fatty acids. That is, they are essential for normal bodily function, but cannot be manufactured in the body. They must be consumed through diet, and can be thought of in the same way as vitamins.
There are two principal types of polyunsaturated fats:
- Those with the first double bond at the third carbon from the omega end of the chain, known as omega-3 or n-3 fatty acids, are typified by fish oil and flaxseed oil
- Those with the first double bond at the sixth carbon from the omega end, that is, omega-6 or n-6 fatty acids, are typified by all the familiar cooking oils, namely sunflower oil, safflower oil, corn oil, and so on.
- Note: These polyunsaturated 'cooking' oils are very poor foods and should be avoided altogether in cooking