Saturated Fat

Please note: If you haven't already read What are Fats?, you may want to read it first.

Saturated fats are naturally occurring in nature and are found in a number of foods such as meat, cheese, cream and butter. They are also high in some fruit such as coconuts and avocados. A saturated fat is defined as containing no double bonds between the carbons in the fatty acids. An example of a saturated fatty acid can be seen bellow.

Because there are no double bonds, there are no ‘kinks' in the chain, which means the chains are very straight (as seen in the above picture). This allows saturated fats to pack closely together, which usually means they form solids at room temperature, which can be seen in coconut oil and butter. The only difference between types of saturated fats are the length of these fatty acid chains, and they can vary from 3 carbons (propionic acid) to 36 (hexatriacontanoic acid).

Saturated fats are one of the more common topics in the media, and we are told to keep our consumption of these fats to a minimum, but we are told that foods high in saturated fats are good for us, such as coconuts and avocados (coconut oil can be 92% saturated fats). So why are we being told different things?

There has been much research into the effects of saturated fats on our health. Many of which have been very high profile but sadly some are a perfect example of bad science. One such example is a study by Ancel Keys known as the 7 study case study. This study concluded that animal fats (about 38% saturated fat) caused CHD, which is still a common idea to date. This study was quickly highlighted by the media and has had a great effect on our diet today. This study ignored vast amounts of data which contradicted Keys conclusion, and has since been highly criticised by many. It is also worth noting that most animal fats actually contain more mono-unsaturated fats than saturated fats.This is just one of the many studies on the effects of saturated fats.

This, however, isn't to say saturated fats don't have their draw backs. There is some evidence to suggest that it can have negative effects on our cholesterol levels, and associations have been made with high saturated fat diets and CHD. However, there are too many variables to take into consideration to definitively say that diets high in saturated fats cause CHD. If we look at an extreme diet example we can see just how many things need to be considered.

Imagine someone who just ate cheese or fast food. This diet would be incredibly high in saturated fat, and this person is sure to have a number of health issues including high LDL and a high risk of CHD. But we cannot say that it is because of the high levels of saturated fat which is causing these health issues. This person will be lacking in fibre, various phytonutrients, vitamins and minerals, it could be a deficiency in one or more of these nutrients which is causing the health issues.

Saturated fats do ahve known benefits though. They make a great energy substrate, especially short chain saturated fats (found, for example, in coconut oil). These can convert to ATP (body's source of energy) much faster than other fats. Saturated fats do not have any effect on insulin (unlike carbs) and so will not cause energy slumps. They also contain 9 kcals/g, whereas most carbohydrates contain 4 kcals/g. this means you need to eat less fat to get the same amount of energy. Saturated fats can also contain fat soluble vitamins. These include vitamin E, D and A, all of which are essential for health.