Fats
In addition to proteins and carbohydrates, fats (= lipids) are also among the energy-providing macronutrients. Certain fatty acids are essential, so it is imperative that we supply them with our diet. In today’s blog, we want to take a closer look at the role of fats in the course of a healthy diet.
What are fats?
Fats are the nutrients with the highest energy content. Per 1g, they provide 9.3 kcal, twice as much as 1g of protein or carbohydrates (4.1 kcal). Due to their high energy density, they are therefore ideally suited as long-term energy stores, which we also quickly carry with us in the form of resident waist fat when consuming excessive amounts of food.
In addition to storing energy, fats also serve as energy suppliers (especially fatty acids), as hormones and signal substances, as components of biological membranes and nerve sheaths, and as carriers of flavor and aroma substances. In addition, fats are important for the digestion of fat-soluble vitamins (vit. A, D, E, K).
Fatty acids (FS) are a subgroup of lipids. A basic distinction is made between saturated and unsaturated fatty acids. Chemically, saturated fatty acids differ in that, unlike unsaturated fatty acids, they have no double bonds. The more double bonds a FS has, the more reactive but, also more liquid it is with double bonds.
This is easy to see in the kitchen: plant-based fats such as olive oil or sunflower oil consist largely of unsaturated FS and are liquid. Butter or coconut oil, on the other hand, contain many saturated FS and are therefore solid.
Are fats healthy?
However, the classification of fatty acids into saturated/unsaturated is not the end of the story. They can be subdivided again and also have different properties. Therefore, the question of whether fats are healthy cannot be answered in a generalized way, since, as is so often the case, it depends on the right selection of fats as well as their quality, but also their quantity.
However, it is a fact that the general demonization of dietary fats belongs to history. Fats, as just explained, play an important role in the body and therefore cannot be classified as unhealthy or bad per se.
Although saturated fatty acids are generally considered unfavorable and are associated with increased risk of cardiovascular disease, even large scientific reviews are found with controversial results and do not confirm the connection in some cases.
It is important to know that saturated fatty acids can be divided into short-, medium- and long-chain FS.
Short-chain FS are produced by our intestinal bacteria in the course of digesting dietary fiber and are extremely beneficial to our health.
Medium chain fatty acids (MCT’s) are particularly digested because they reach the liver quickly, where they are usually burned and not stored. Rich in MCT’s is for example coconut oil.
Long-chain saturated fatty acids, on the other hand, tend to be unhealthy. They burn the worst and are stored in the body.
With animal-based fats increasingly containing saturated FS, the recommendation to rely more on plant-based fats became popular in the 1960s. As mentioned, plant-based fats contain an increased amount of unsaturated fatty acids, but here, too, it is important to distinguish between the subtypes and their health advantages/disadvantages.
One can distinguish monounsaturated FS from polyunsaturated FS. One representative of monounsaturated fatty acids is oleic acid, which appears to be particularly beneficial to health. It is predominantly found in olive oil and, along with other nutrients and polyphenols, is responsible for olive oil being one of the healthiest sources of fat.
The polyunsaturated FS include the omega-3 FS as well as the omega-6 FS. Both are essential and therefore important for the body.
Omega-3-FS are associated with positive health effects such as anti-inflammation, vasodilatation or improvement of cell membrane mobility. Too much omega-6, on the other hand, is associated with adverse health effects such as systemic inflammation, vasoconstriction and insulin resistance. Thus, it becomes problematic when there is an excess of omega-6 fatty acids, as these are the starting substance for pro-inflammatory messenger substances.
Since many vegetable oils contain predominantly omega-6-FS, the consumption of omega-6-FS linoleic acid increased by 250% between 1909 and 1999. Thus, many people have a much too dominant ratio towards omega-6 which is detrimental to health. Therefore, a simple generalization into “healthy vegetable fats” and “unhealthy animal fats” is too short-thought and simply wrong.
So what are good sources of fat?
In summary, we can say that it makes sense to consume mainly monounsaturated fats, such as those found in olive oil. Saturated FS, especially in the form of MCT’s — such as those found in coconut oil — also have a place in a healthy diet. Industrial cooking oils should be avoided because they have a high omega-6 content.
On the other hand, one should consume a lot of Omega-3-FS. They are found, for example, in oily fish, nuts or seeds. If you want to avoid fish, you are well advised to take additional algae oil, as the other plant sources of omega-3s differ from animal sources.
How much fat do I need?
The German Nutrition Society (DGE) recommends consuming about 30% of your total calories in the form of fats. However, studies show that, to a certain extent, even a higher proportion of fat is not detrimental to health. It is important to select the right sources of fat.
Text-Sources:
(1) Biesalski, H. (2018) Ernährungsmedizin. (5. Auflage) Georg Thieme Verlag.
(2) Schmiedel, V. (2019) Nährstofftherapie. (4. Auflage) Georg Thieme Verlag
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(4) https://www.dge.de/wissenschaft/referenzwerte/
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