Macronutrients: Fats or lipids

Lipids or fats

The fat is located under the skin, serving as energy reserve, producing more than twice the energy that the liberated by protein and carbohydrates. It also acts as insulation against the cold and form a fabric of support of many organs, at the same time protecting them from shock, as it is the case with the kidneys.
Fat helps make food more enjoyable, since the presence of this in the meals is essential to appreciate the aroma and taste of different foods, also helping the feeling of fullness that we have when we eat it.
It is always essential to health, therefore must be included in any diet in adequate amounts.

Need to lipids in the diet

In general, the term 'fat' has negative connotations for health. However, nutritionists know that fat is an essential and necessary nutrients like carbohydrates, proteins or carbohydrates.
Although currently not has been agreed requirements for intake of lipids, consumption should provide aprioximadamente 30-35% of the total energy of the diet.
It is important that we bear in mind that this percentage is 10% below what the Spanish population regularly consumes.

Types of lipids

Lipids are a very diverse group of organic compounds mainly consisting of carbon, hydrogen and oxygen, sometimes being able to contain sulphur, nitrogen or phosphorus.
There are three types of lipids in the different foods we eat: fats, phospholipids, and cholesterol.

Fat

Saturated fat:

They are considered as 'bad fats', which when consumed in excess can cause cholesterol problems and disorders of circulation. It must be borne in mind that the high consumption of this type of fat, along with cholesterol from food, can cause serious heart problems, due to the hardening of the arteries (atherosclerosis).
Most saturated fats come from foods of animal origin such as red meat and butter. Palm and coconut oils are also rich in fat.

Unsaturated fats:

Most of the unsaturated fats are oils, since at room temperature are in the liquid state. They are beneficial to health fats because they regulate the level of cholesterol and prevent cardiovascular disease. They can be:

• Monounsaturated fats: present in the olive, rapeseed oil, nuts (pistachios, almonds, hazelnuts, macadamia nuts or cashews), peanuts, avocados and their oils.
  
• Polyunsaturated fats: found in the sunflower oil, fish oil, soybean oil, corn, saffron, and also in oily fish such as salmon, tuna, sardines...
  At the same time, polyunsaturated fats are subdivided into different types, highlighting two classes for its properties:
  • The omega-3 fats are present in a multitude of fish as oily fish (salmon, mackerel, tuna, sardines, trout and anchovies; and also in different nuts and oils as walnuts, rapeseed, soybeans and their oils.) Omega 3 best known is linoleic acid.
    
  • Omega 6 fats them can be found in the seeds of sunflower, wheat germ, Sesame, walnuts, soybean, corn and their oils. The best known is linolenic acid.
    Linoleic acid and linolenic acid can not be synthesized in the body and, therefore, must be obtained through diet (essential fatty acids).
• Trans fats: these fats are produced through a chemical process called hydrogenation and consists of adding hydrogen to vegetable oils. This procedure is used to enhance the flavor and improve the texture of food products, prolonging their useful life with a low cost. However, hydrogenation causes a part of polyunsaturated fats from becoming saturated fat which, as we have seen, is not suitable to abuse. For this reason, it is advisable to check labels to check if it contains trans fat, and limit their consumption.

Phospholipids

The contribution of fatty acids is of less importance in the case of triglycerides. These involved in the functions of lipid transport and also have a structural role constituting the cell membrane.

Cholesterol

It plays different roles within the Organization, although it is not considered an essential nutrient. Its functions include:

• Structural: It is essential in the formation of the cell membrane.
  
• Precursor in the synthesis of sex hormones such as testosterone and cortisol.
  
• Precursor in the synthesis of bile salts: these emulsified fatty acids to make them more soluble in water, facilitating their absorption.

We can be found in the following foods: cream, yolk of egg, butter, bacon, butter, milk, coconut oil, lean meat, nuts, avocado, oils: olive, seeds, etc. Oily, such as salmon, sardines, trout, tuna fish.
Foods rich in phospholipids:

• Eggs.
  
• Meat.

Cholesterol-rich foods:

• Pork liver.
  
• Veal brains.
  
• Veal meat.
  
• Egg yolk.

Function of lipids

Lipids are different functions in the body such as:

• Energy: can be used as energy reserve, since they provide more than twice the power than that produced by carbohydrates.
  
• Regulator: for example, cholesterol is a precursor of sex hormones and vitamin D, which perform regulatory functions.
  
• Transport: dietary fat supplies essential fatty acids, i.e., linolenic acid and linoleic acid, being required to transport vitamins A, D, E and K, which are soluble in fats and to assist in its intestinal absorption.
  
• Structural: there are various lipids, such as cholesterol and phospholipids, which are part of biological membranes.

Article contributed for educational purposes