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Why Do We Need To Eat Fats?

General health Nutrition

Why Do We Need To Eat Fats?

Ava Morris April 23, 2018

In our opinion, fats have been totally doomed to oblivion without good reason. Here we tell you why we all need to eat fats, as well as the dangers of a fat-free diet and low fat content in the human body.

What are fats?

Almost every fat consists of glycerin with fatty acids called “triglyceride”. So, if you ever see triglyceride in the contents of a product, you know that this means fat.

Useful and harmful fatsOne of the components of glycerin fat is, basically, an alcoholic spirit. However, it doesn’t look like a regular spirit and has neither the smell, taste, nor consistency. It’s a family of alcoholic spirits only because it has OH atoms in its molecular formula. Fatty acid – the second component – can chemically connect to these OH atoms.

Fatty acids differ in the number of double bonds between carbon atoms. If there are no double bonds then an acid is “saturated”. If there are double bonds, then it’s “unsaturated”. Depending on the number of double bonds, acids can be monounsaturated (meaning they have one double bond) or polyunsaturated (meaning they have several). The corresponding name receives the type of fat that contains such acid.

These chemical details have large and completely different consequences for the body, as they divide fats into two different groups: conditionally good and conditionally bad.

What kinds of fats exist?

Unsaturated Fats

In order to live a full and healthy life, we need four polyunsaturated fatty acids: linoleic, linolenic, arachidonic and docosahexaenoic. These refer to omega-3 and omega-6 acids, whose benefits are well known to everyone who is interested in nutrition.

These wonderful omega acids lower cholesterol levels, clean the blood vessels and restore their elasticity, prevent the formation of blood clots, have antioxidant effects (also known as “rejuvenating” effects), normalize arterial pressure, prevent strokes and heart attacks, improve blood supply to the brain and limbs, promote the renewal and development of CNS cells, speed up the restoration of bone tissue and bone callus formation in fractures, and improve ligament condition. Omega-3 acids also have anti-inflammatory action.

With a lack of omega-3, your vision becomes impaired, muscle atrophy develops, and numbing of the arms and legs develops. Children deficient in omega-3 have stunted growth. Research shows that people become more prone to negative thoughts when there’s a lack of omega-3 in their blood.

Omega-3 is usually found in sea-dwelling animals: oily fish (e.g. mackerel, herring, sardines, tuna, trout, salmon, sprats, mullet and halibut) and other kinds of ocean inhabitants (e.g. squids and anchovies). In the vegetable kingdom, there’s a large amount of omega-3 in pumpkin seeds, soybeans, walnuts, dark green leafy vegetables and vegetable oils (e.g. linseed, grape seed, sesame, and soybean oil).

Products containing omega 3 and 6Linoleic acid (i.e. omega-6 acid) normalizes lipid exchange, decreases skin dryness, supports the normal state of cellular membranes, and lowers fatty filtration of the liver. Omega-6 can be found in almost all of the same foods as omega-3. In cases of omega-6 deficiency, people can experience tetter, hair loss or even dyslipidemia.

There’s actually one more fatty acid: omega-9, which can be found in olive oil and almond oil. This is a monounsaturated oleic acid. The human body can synthesize it, but it’s better to absorb it from food. This helps it to digest properly. Omega-9 is the only acid that doesn’t affect cholesterol levels.

With a deficiency in omega-9, a person can develop weakness, rapid fatigue, deterioration of the digestive function, constipation, dry skin and hair, brittle nails, and dryness of the vagina among women.

Saturated Fats

Saturated FatsSaturated fats lower the body’s sensitivity to cholesterol and are eliminated from the bloodstream far less efficiently. Therefore, there’s an increased risk of cholesterol deposits on the walls of the blood vessels. However, saturated fatty acids have one big advantage — they provide the body with energy, but you should still consume them moderately.

Saturated fatty acids “hitchhike” with unsaturated fats. They’re present in foods like butter, lard, and meat.


The news outlets try to frighten us with incessant warnings about cholesterol, but they do so in vain. Cholesterol, like any other fat, is highly necessary for our body. It’s beneficial in moderation and harmful in excess.

Cholesterol is a content of the cell membrane, which is used to synthesize sex hormones (estrogen, testosterone, progesterone), as well as stress hormones (cortisol, aldosterone), vitamin D and bile acids.

Cholesterol increases the production of serotonin – the “feel good hormone”, which is why low mood is common with a low-cholesterol diet.

However, our body produces the larger part of necessary cholesterol (about 80 percent) by itself and only about 20 percent comes from food. Excessive consumption of cholesterol is dangerous due to the risk of plaque formation in the blood vessels, with several possible outcomes manifested in illnesses like atherosclerosis.

Cholesterol is contained in animal products, such as eggs, meat and dairy. The largest amount of cholesterol is contained in the brains of animals and bird eggs, while fish contains a little less.


Cholesterol (on average),  mg/100g

Cholesterol, mg/100g, from to
Brains 1500 770-2300
Kidneys 600 300-800
Egg Yolk 450 400-500
Caviar 300 300
Crawfish 200 200
Butter 185 180-190
Shrimp, Crab 150 150
Carp 185 100-270
Cow/Pig Lard 110 100-120
Pork 100 90-110
Beef 85 80-90
Duck (with skin) 90 90
Veal 80 80
Duck (without skin) 60 60
Turkey 40 40
Chicken 20 20

Note: two egg yolks contain about 400 milligrams of cholesterol, which is the recommended daily allowance.


This is a type of polyunsaturated fat. Trans-fats contain trans isomer fatty acids, meaning that they have hydrocarbon substituents on opposite sides of the double carbon bond — the so-called “trans configuration”. That’s why they have such an unusual name.

The main sources of these highly undesirable fats are margarines and spreads. What’s interesting is that they were created with good intentions, as a healthy non-cholesterol alternative to natural products. There’s also an insignificant amount of trans fat in milk and meat.

Content of trans-fats in foods

 Product Content, %
Milk Fat 2,3-8,6
Beef Fat 2,0-6,0
Hydrogenated Tallow 35-67
Raw Vegetable Oils <0,5
Refined Vegetable Oils <1
Soft Margarines 0,1-17
Baking Margarines 20-40
Culinary Fats 18-46
Spreads 1,5-6

Trans fats significantly increase the life term of a product, so they’ve gradually replaced more expensive and shorter lifespan products, such as natural hard fats and liquid oils. The critical limit for consumption of trans fats is 6-7 grams per day. In order not to exceed this norm, avoid eating margarines, spreads and culinary fats.

There’s another problem with trans fats. They lose many of their positive properties due to various alterations and they gain negative ones. They not only increase the level of cholesterol in the body, but they also prevent the half-life process of undesirable fats and the formation of vitally important fatty acids.

How much fat should we consume?

The recommended ratio of fatsThe recommended ratio of proteins, fats and carbohydrates for a healthy diet is 1:1:4 (in mass). You shouldn’t consume any more than 30 percent of fat in your daily food intake. The optimal ratio of fats for your diet is 70 percent animal fat (received from fish, meat & dairy products) and 30 percent vegetable fat (e.g. vegetable oil and nuts).

You should consume saturated, monounsaturated and polyunsaturated fatty acids at a ratio of 3:6:1. However, almost every product containing fatty acids already has a combination close to this ratio, so there’s no need to worry about making tiresome calculations as long as you have a balanced diet. You should consume beneficial fatty acids only if there are direct indications for it.

The conclusion? Everything is okay in moderation. Yes, all of the fats mentioned above are beneficial in moderation, and the human body can’t function properly without them. However, consuming too much is not a good idea. You should certainly avoid any sharp increase in fats in your diet if you want to ward off diseases.