Nutrients, What Is It? Lipids

Lipids or fats are the other large group of organic or macronutrients. They are a diverse group of water-insoluble organic compounds. They are a high-energy source for the body, releasing more energy per gram compared to carbohydrates and proteins.

Some types of lipids are associated with an increased risk of chronic diseases, while others (essential fatty acids) are important for our health. Triglycerides are an important source of energy when we rest or during light to medium exercise. The human body tends to accumulate large amounts of triglycerides, which are converted into adipose tissue or body fat. These stocks are burned during long starvations - diets or fasting. Foods rich in fat are also a source of fat-soluble vitamins.

Globally, measures are being taken to reduce fat consumption, as excessive consumption is the cause of overweight and heart disease. This does not mean that fats should be completely excluded from our menu. They are vital for the normal functioning of cells.

Triglycerides are the type of lipids that are found in the largest amounts in food. About 95% of all fats we consume are triglycerides. These are the fats that accumulate in our body. Fats are classified according to various criteria, one of which is the level of saturation, which affects their nutritional qualities. They are saturated and unsaturated.

Some foods that contain saturated fatty acids are coconut oil, palm kernel oil, cow butter, cheese, whole milk, lard and beef fat. Unsaturated fats have one (monounsaturated) or several double bonds (polyunsaturated) in their molecule. At room temperature they are liquid. Polyunsaturated fats are also liquid at room temperature. Foods containing polyunsaturated fats are cottonseed, rapeseed, corn seed oil and saffron oil.

The amount of fat varies in different foods. Thus, for example, animal fats contain between 40 and 60% saturated fatty acids, vegetable fats contain 80-90% monounsaturated fatty acids.

The human body synthesizes only saturated fats. And we have to get the unsaturated from food. They are also called essential. The two main essential fatty acids in our menu are linoleic and alpha-linolenic.

Linoleic acid is also known as omega-6 fatty acid. It is found in vegetables, sunflower seeds, corn, soybeans. If your diet is rich in vegetables and nuts, you are probably getting the necessary doses of omega-6 fatty acids.

Alpha-linolenic acid , also called omega-3. Rich in omega-3 are dark green leafy vegetables, flaxseed and oil, soy and soybean oil, walnuts and walnut oil, rapeseed oil. Omega-3 fats are also found in fish (salmon, tuna, cod).

How does the body break down fat? Because lipids are water-insoluble, their absorption is not so easy. The enzyme lipase, which is found in saliva, has a minimal role in the breakdown of lipids. They reach the stomach almost completely. Their hydrophobic nature requires the intervention of bile secreted by the gallbladder and digestive enzymes from the pancreas. As lipids enter the small intestine from the stomach, the gallbladder releases bile. It functions as an emulsifier, which manages to break down fats into smaller units, thus increasing their total surface area. As such, pancreatic enzymes begin to break them down.

Curious . Dissolving fat in our small intestines can be likened to making mayonnaise. The oil and acid are mixed (dissolved) by adding an egg. It contains lecithin, which acts like bile as an emulsifier.
Excess fat is stored in adipose tissue. Once in our body, fats can be broken down immediately and used as a source of energy. Excess accumulates in fat deposits.

Why do we need fat?

Well, first of all, they are a rich source of energy. They provide twice as much energy per gram of product compared to carbohydrates and proteins. During intense physical activity, fats provide the body's energy needs. During aerobic exercise, lipid stores become active and begin to break down. The brain begins to signal the body to break down the accumulated fat in the depots to provide enough energy for the working muscles. Lipids are released from fat deposits and through transport proteins reach the places where energy is needed. 

They are also involved in the construction of cell membranes, protect the DNA molecule from damage, help the body with infection and are vital for the proper development of the fetus during pregnancy. 

Fatty ones give taste and pleasant texture to food. They make the salad dressing rich and filling, the ice cream - delicious and the type of cookies and cakes - captivating. Frying food in melted fat or oil, such as donuts or french fries, gives them crispiness and a delicious appearance. Despite their taste, regular consumption of such foods is unhealthy as they are rich in saturated and trans fats.