You don’t need a textbook of organic chemistry to learn how to cook and eat healthier, but what you need to know is the difference between saturated and unsaturated fatty acids. You don’t need to know what is COOH and CH 3 and no need to know how to count the number of carbon atoms in the fatty acid to understand the difference between fat we eat today and fat we ate in the past. This is the knowledge you really need, but only in a most basic level.

What you need to do is to notice the difference between simple pictures. We all know what the ordinary train looks like, we all know that couples hold hands and we all have enough imagination to understand short fictional stories.

First things first – terminology: we are used to say fat or oil for what is actually a fatty acid. When we use the word saturated fat, monounsaturated oil, polyunsaturated oil – we are actually talking about saturated and unsaturated fatty acids.

It’s more correct to say: saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids and trans fatty acids. Because there is no 100% polyunsaturated oil, and there is no fat which is 100% saturated. They are all a mixture of different fatty acids. It is correct to say that some fats are mostly saturated or oil is mainly polyunsaturated. It’s fine that people have adopted all this, you just need to know what is right.


I’m going to use the train as a metaphor for fatty acids, of course locomotives and boxcars are included. (In reality locomotive is indicated as CH 3 and a boxcar is COOH, but that’s not important).

One molecule of fat (more accurate expression is lipid or triglyceride) consists of a train station in which 3 trains are parked. (In reality, fat is a glycerol molecule to which three fatty acids are attached, but this isn’t important either, because we’re talking about train stations). Train station don’t have to have trains that look the same

Imagine that these trains are like children’s toys, made from Legos, and are able to bend and curve and have different letter shapes. These letters don’t necessarily contain the same number of boxcars (they aren’t the same length)

The letters “I”, which are not the same length

saturated fats

The letters “V”, which are not the same length

monounsaturated fats

The letters “C”, which are not the same length


If the station has three parked trains, they don’t have to have the same number of wagons. Usually the station has, let’s say, one ’I’ train and two ‘V’ trains – or a ’V’ train and two ‘C’ trains, etc. And still in these combinations none of the letters need to be the same length, and therefore all these stations look different.

How many of these train stations? One teaspoon of oil has about 15 drops. In every drop there is about 63 × 10¹8 train stations with different number of parked trains. I cannot even pronounce the name of this number.


Why are the letters of different shapes?

In places where the letters V and C curve, the train is not flexible but has one or more “fixed positions”. These are the places where there are duplicate (unsaturated) connections. But to make this easier – let’s imagine that in those places is not some complicated “double bond”, but that there is a couple in love on each curve. Couple is sitting in a precisely defined boxcar and they hold hands.

Therefore, it is clear that if the train has only one couple that is a mono (monounsaturated train) and if there is more than one, this is poly (polyunsaturated train). But let’s take it slow…

The ‘I’ letter shaped train – saturated fatty acids

If the “curve” is the place where the couple in love is sitting holding hands – it is clear that in the letter ‘I’ shaped train, without curves, there is no couple holding hands, and that is why this train is completely straight.


The most of these fatty acids are found in animal foods we eat. Train that is 16 and 18 boxcars long, we call it a long train. Since there are no couples in love in this train, clearly that there’s no any drama and it is not as exciting – because it is stable. This is the reason why our body stores energy in the form of fat that look like these trains, precisely because they are stable (and the importance of this will be clear by the end of the article).

The ‘V’ letter shaped train – monounsaturated fatty acids

In this train there is only one couple holding hands, and the curve is the exact place where the couple is sitting – this is the curve of the letter ‘V’.

monounsaturated oil

Since in this train there is only one couple in love, we can expect a dramatic situation. Therefore this train becomes less stable than the first train where there are no couples. However, there’s only one couple so we cannot expect any great drama.

In the real world this is how monounsaturated fatty acids looks like.

The ‘C’ letter shaped train – polyunsaturated fatty acids

Since the curve appears only in a place where the couple is sitting, ’C’ means that this train has at least two couples in love, but in separated boxcars that are not next to each other.


As you can see in the picture, there are at least two couples – and there could be more. In reality there can be from 2 up to 6 couples in love! They usually sit in boxcars 3, 6, 9, 12 and 15 (we said that we’re counting the locomotive too).

In reality these are polyunsaturated fatty acids that are dominant in sunflower, soybean, corn or grape seed oil.

What can happen to a couple sitting in the train?

When a couple goes on a trip, anything can happen. If there’s more than one couple in one place, the chances of trouble are higher. Remember how many train stations in just one teaspoon of oil! Imagine if train station had only this kind of trains, with several couples in each train, the possibility of trouble endless.

Here they are – sitting in a precise boxcar and holding both hands. They are holding with both hands because this represents double bond. No matter how this picture looks, and if they are happy and stable now – they are not stable at all. Double bond is not stable – because there’s always someone who wants to separate the two of them.

Basic three situations that can happen on a train and disrupt the couple are as follows:

The first situation: the case of a woman gone mad

When she agreed to go on the trip, the girl pointed out that she doesn’t like too much light and excessive heat because she is very sensitive. She didn’t say the whole truth, because the light and the heat actually make the total lunatic out of her. As the air conditioner doesn’t work and there is no curtain, the girl goes insane. She gets up completely mad and starts detaching boxcars from the train – exactly where she was sitting with her dear. When other girls from different boxcars saw this (they are also sensitive to heat and light), they go crazy too. Because of the crazy woman the whole train falls apart and disaster is inevitable.

fat oxidation

Now let’s get serious: The oxidation of fatty acids should occur in the body during digestion, in a specific order. The order is most often like this – two trains go away from the station and one train remains in the station, and that way they travel through the body. Also, trains should be intact and preserved.

If detaching starts while all the trains are still in the station and outside the human body – we can talk about spoiling. These types of fats and oil are called rancid. This can happen only in places where the couple was.

Antioxidants in oils protect trains from falling apart (they are like valium for crazy girl), but antioxidants can be found only in cold pressed and properly stored oils. Refined vegetable oils that are kept in clear plastic bottles have already been processed, that you cannot feel the bad smell. And just how many crazy women are in the bottle, you can imagine.

The second situation: A James Bond movie

Imagine that someone jumped on the train. It happens in James Bond movies, so it can happen in this article as well J Since these are all good people, they want to help the guys on the train, so they don’t fall off. They raise one arm in the air to support the ‘train jumpers’.


Let’s say that one couple raises one hand as a support.


If there were two couples and both raised their hands, then we no longer have anyone who’s holding with both hands. We said that it’s important that the couple holds both hands together, because when there’s no holding with both hands – no more curves in the train. If there’s no curves, the train becomes straight.

complete hydrogenation

Now let’s get serious: Cis-bond is when both hands are raised in the air, so that boyfriend and a girlfriend are now holding with just one hand.

In reality jumpers are hydrogen (H). As soon as boyfriend and girlfriend release their hands and raise them up in the air to hold on to a jumper – the train becomes ‘I’ train. This their wagon is no longer in no way special, but becomes the same as all other cars on the train. Their boxcar is no longer special, and becomes the same as all other boxcars on the train. If ‘C’ train becomes ‘I’ train, in this way we understand that there has been a transition from polyunsaturated fatty acids to saturated fatty acids. The process by which this is achieved is complete hydrogenation.

It can be done in the lab, but it can also work in our body. Our body can make the most of the trains by itself from the trains it already has – except for those we call essential Omega 3 and 6 trains.

The third situation: a heartbreaking melodrama

Let’s say that he proposes to her, and she says “no”, of course something bad is going to happen. He becomes desperate and decides to jump off the train. The girlfriend saves him, because they are still holding with both hands, while he hangs out the window in a difficult position.

trans bond

We all know how risky it can be for someone to hang out the window of the train, and it is also very unsafe. The train twists, bents and at some point it is even “upside down” (the example is shown in the pictures below, boxcars 7 and 9 are upside down):

partial hydrogenation

Now let’s get serious: It would be enough that only one couple gets into this position and the entire train would be called trans fat.

If this happens only in one boxcar, due to twisting of that car – to someone who watches all this outside of the train, the train would seem just fine. It would look like the ‘I’ shaped train. But it cannot be a real ‘I’ train, because there’s no couple holding both hands in the ‘I’ train! That is why this train is at the same time “false ‘I’ train” and “false ‘C’ train.” Simple deception and optical illusion.

This twisting is called partial hydrogenation. It is a process that creates artificial fats that do not exist in nature. This is the case where a man is bombarding the train with jumpers to separate the couple, but when he fails to separate them, he brings them into this terrible and dangerous situation.

That is how vegetable fats and margarine are made. There are also margarine with no trans fats and they are made by another process.

Anyway, the idea of partial hydrogenation was to stabilize the girl so she wouldn’t run around the train detaching boxcars. It was thought that while they are busy because the boyfriend is hanging out the window of the train – train can be stable, and they were wrong. In fact, the train has just become deception and optical illusions. In the end our body gets cheated because it doesn’t know what the train actually is, so it uses it incorrectly.

How would it actually look like in chemistry class?

Here’s how Cis and Trans really look like in the example of one small part of the “train”. If you carefully read the text, I am sure that now you can look at this picture and understand something even though you’ve completely forgotten the chemistry that you learned in school:


  • Bottom left is complete hydrogenation. Double bond no longer exists, and this fatty acid now seems saturated. These are train jumpers.
  • Bottom right is a partial hydrogenation, a failed marriage proposal and jumping off the train. Double bond still exists, but fatty acid is “straightened” at this point, and now it looks like straight saturated. But that’s just an illusion!

We know that many would fall for looks, but when they get to know the person they get confused and disappointed. This is exactly what happens to our body when we consume trans-fatty acids. That is, when we eat margarine, vegetable cheese, vegetable cream…

Just when you think you’ve stumbled upon the ravishing Saturated Beauty, it turns out that you’re dealing with the Trans schizophrenic who has a completely different personality.

Ivan is a exercise enthusiast and has a great passion for healthy living. He is extremely dedicated, motivated and passionate towards achieving positive results and has a genuine interest in helping others achieve their goals. His motto is "If we work together, the success will come twice as fast!" His mission is to provide others with nutrition and diet tips, workout advice and anything else that will help promote a healthier lifestyle.