Download
Factsheet What is fat
Types of fatty acids
The body needs fats every day. In a healthy diet between twenty and forty % of the daily calories are obtained from fat. Fats are an important source of the vitamins A, D and E and essential fatty acids. But not all fats are the same. This fact sheet contains information about the different types of fats and their health aspects. The applicability of the various fats in the production of foodstuffs is dealt with in the fact sheet ‘Functions of fats’.
A fat consists of triglycerides. One fat molecule, a triglyceride, is an ester that is formed from a molecule of glycerol coupled with three fatty acids. There are two types of these fatty acids: saturated and unsaturated fatty acids. Unsaturated fatty acids can be divided into the monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). Mono refers to the presence of just one double bond in the chemical structure of the fat, while poly means that more than one such bond is present. Unsaturated fatty acids can occur as the cis-variant and the trans-variant, although in practice when unsaturated fatty acids are referred to only the cis-variants are meant. Trans-unsaturated fatty acids are usually referred to just as trans fatty acids.
Essential fatty acids
Essential fatty acids are polyunsaturated fatty acids that cannot be made by our body. These fatty acids must, therefore, form part of our daily diet. Essential fatty acids are vital parts of the production of hormones in the body. At the present time these fatty acids are attracting a great deal of attention, particularly the omega-3 fatty acids. These include alpha-linolenic acid (ALA) from vegetable oils and the fatty acids EPA and DHA from fish. (ALA can be converted into EPA and DHA in the body, but this only takes place to a limited extent.) As well as the omega-3 fatty acids there are also omega-6 fatty acids. The most well known of this is the essential acid linoleic acid from vegetable oils.
