The 3 types of fat (unsaturated, saturated and trans)

The world of nutrition is complex and, therefore, it is normal that on a social level there are many misconceptions that we have about what a healthy diet is. And in this context, one of the most frequent and at the same time most incorrect beliefs is that "fats are bad". Nothing could be further from the truth.

Macronutrients are chemically complex molecules that constitute the mainstay of metabolism, being bioassimilable organic chemicals that, as such, can be digested, absorbed and used in the body's metabolic reactions to obtain the matter and energy necessary to live.

And it is carbohydrates, proteins and, of course, fats, which make up this group of macronutrients. And as such, these fats are totally essential for our body. And despite being demonized, they are essential for healthy eating. You just have to know how to distinguish which are good and which are bad.

And this is precisely what we will do in today's article and in the hands of the most prestigious scientific publications. We will analyze the nutritional properties of the three main types of fats (unsaturated, saturated and trans), their effects on the body and the products that contain them. Let us begin.

What exactly are fats?

Fats or lipids are a type of macronutrient that the body uses to obtain energy, absorb vitamins, regulate body temperature, maintain the correct structure of our cells, stimulate the functioning of the nervous system or promote blood circulation.

These are water-insoluble substances that are part of the structure of living beings (Cell membranes are made up of lipids) and they consist of more or less long chains made up of carbon, hydrogen, oxygen, phosphorus, nitrogen, sulfur and even other biomolecules such as proteins.

Thus, we must conceive of fats as nutrients rather than as the tissues of being overweight, which are nothing more than a manifestation that there is an excess of these lipids, which must be "stored" in the form of fatty tissue. But fats are not, by themselves, bad.

Fat intake deficits can lead to serious health problems in many body systems and, obviously, excesses as well. Like everything when it comes to nutrition, both deficiencies and excesses are bad. The important thing is, as we have said, to know which are the healthy fats, which are the least healthy and where they can be obtained.

And in this sense, the different types of fats that we will analyze below differ from each other according to their chemical structure. Depending on what types of bonds they present in their chemical structure and how long the lipid chain is (in addition to the possible artificial treatments that you have followed), the fats will be saturated, unsaturated or trans. And now is the time to analyze them.

How are fats classified?

Before we start and as a summary, the most important thing is that, broadly speaking, unsaturated fats are good and saturated and trans fats are bad. Although there are nuances that should be discussed (and that we will discuss) this would be the general idea. That said, we are going to see the characteristics, nutritional properties and sources of obtaining the different types of fats.

1. Unsaturated fats

Unsaturated fats are the healthiest and the ones that must be indisputably part of our diet. They can be differentiated from saturated and trans because, due to their molecular structure, they are liquid at room temperature. They are essential fats for the health of our entire body.

At the biochemical level, unsaturated fats are long chains of carbon atoms with different molecular groups (other atoms of different elements or other biomolecules) linked together, forming one or more double bonds between said carbon atoms. This chemical structure is what explains why, at room temperature, these fats are liquid.

And at the nutritional level, these unsaturated fats help us increase HDL cholesterol levels ("good" cholesterol, essential to build the cell membrane, ensure proper blood fluidity, metabolize vitamins, synthesize hormones, etc.) and lower the levels of LDL cholesterol ("bad" cholesterol, which accumulates in the walls blood vessels and can cause serious cardiovascular problems).

Thus, the consumption of unsaturated fats, in addition to protecting us from hypercholesterolemia, are positive for obtaining energy, absorbing vitamins (especially A, D, E and K), absorbing calcium, developing antioxidant function, keeping the system healthy. nervous, promote blood circulation, keep bones and teeth healthy, help skin and hair look young, healthy and hydrated, regulate inflammatory processes ... They have many benefits.

The WHO recommends that between 20% and 35% of the daily caloric intake should be in the form of unsaturated fats, which are found mainly in blue fish, nuts, avocado, olive oil, legumes, sunflower seeds, corn and eggs. These are the best sources of healthy fats, but keep in mind that there are two types of unsaturated fats.

1.1. Monounsaturated fats

Monounsaturated fats are those that have a single carbon-carbon double bond in the lipid chain. They are healthy fats that should represent between 15% and 20% of the daily caloric intake and are mainly found in vegetable oils (especially olive), nuts and avocados. They maintain HDL cholesterol levels and reduce LDL, although consuming products rich in these fats without reducing the consumption of saturated ones can prevent us from benefiting from these effects.

1.2. Polyunsaturated fats

Polyunsaturated fats are those that have more than one carbon-carbon double bond in the lipid chain. They are found in, in addition to vegetable oils, in fish and shellfish. Polyunsaturated fats should represent between 6% and 11% of the daily caloric intake and the most important are the well-known omega-3 (present mainly in oily fish) and omega-6 (present mainly in corn oil , safflower and soy).

2. Saturated fat

We enter the group of "bad" fats. Saturated fats are unhealthy fats that there is no reason to include them in the diet. Anyway, if it is in moderation and never representing more than 6% of the daily caloric intake, nothing happens if they are consumed. They differ from the unsaturated very easily since they are those that are solid at room temperature.

At the biochemical level, saturated fats are lipid chains where there are no double bonds between the carbon atoms, as is the case in monounsaturated (there is one) or polyunsaturated (there is more than one), so they are simple chains. This makes them solid at room temperature.

At the nutritional level, as we have said, there is no reason to include them in the diet, since they do not provide the benefits that we have detailed when we talked about unsaturated ones. The problem is that most foods that we consider rich have saturated fat in their composition. Hence its consumption is allowed but always below 10% of the daily caloric intake. And if it can be 6%, the better.

And it is that in addition to not having positive effects on the health of the body, they stimulate the increase in the levels of LDL cholesterol, which, as we have said, is the "bad" one, the one that accumulates, due to its low density, in the walls of the blood vessels, which can cause severe cardiovascular problems. The main sources of saturated fat are red meat, whole milk, cheeses, butter, cream, and ice cream.

3. Trans fats

We got to the really bad times. Trans fats are unhealthy fatsTherefore, it is no longer that its consumption should be moderated as in the case of saturated ones (which, although unhealthy, can be consumed in moderation), but rather that we would have to completely avoid them. Obviously, they have no benefits in the body and contribute much more to increase blood levels of LDL cholesterol.

At the biochemical level, it is about fats that consist of simple lipid chains that have undergone a hydrogenation process (addition of hydrogen so that the oils are transformed into solid fats and thus increase the shelf life of the product) that makes them even more harmful to health than saturated fats . They are also solid at room temperature and, as we say, we would have to avoid them entirely.

Trans fats are found in ultra-processed products, industrial pastries, cookies, potato chips and, in short, any product whose label indicates that it has been made from partially or totally hydrogenated fats. Evidently, We can indulge ourselves from time to time, but they cannot be part of our daily diet.

And it is that in a study carried out in a population of 14,000 subjects, it was shown that those individuals who consumed more than 2% of their daily caloric intake in the form of trans fats had a 23% greater risk of suffering from cardiovascular diseases compared to those that they did not ingest these fats so harmful to the organism.