Fats

Fats, along with proteins and carbohydrates, are the fundamental building blocks of our body. They perform a number of essential functions:

• they are solvents for vitamins A, D, E, K,
• they are essential for the formation of sex and adrenal hormones,
• they form a structural component of cell membranes,
• they are a very important energy reserve - 1 gram of fat contains approximately twice as much energy (9 kcal) as the same amount of carbohydrates or proteins. For this reason, they are the greatest threat to unwanted fat accumulation in the body.

In general, the richest sources of fats are nuts and seeds, as well as olives, soybeans, fatty meats, and some dairy products.

To adjust our diet in the desired way by manipulating the fat content, it is first necessary to understand their structure and classification. Fats are actually part of a broader group called lipids. Chemically, they are divided into:

1. Simple lipids (esters of fatty acids with various alcohols):
     a) fats and oils (esters of fatty acids with glycerol),
     b) waxes (esters of fatty acids with higher monohydric alcohols).
2. Compound lipids (esters containing, besides fatty acids and alcohol, additional groups):
   These include phospholipids, glycolipids, sulfolipids, and aminolipids.

Fats contained in food are called triacylglycerols or triglycerides and are composed of three fatty acids attached to glycerol. Based on this, a simple system is presented based on the fatty acid content, whereby fats are divided into:

1. Saturated

In the chemical structure of saturated fats, the carbon atoms are saturated with hydrogen atoms:

They are found in the largest amount and proportion in foods of animal origin (less in plant sources). It is generally true for saturated fats that they solidify in cold conditions and are opaque. The higher the temperature at which they remain solid, the more saturated fatty acids they contain.

2. Unsaturated

In the chemical structure of unsaturated fats, there is a double bond – some carbon atoms are not fully saturated with hydrogen atoms:

Unsaturated fatty acids are further divided into monounsaturated and polyunsaturated.

Monounsaturated

Based on the position of the first double bond, unsaturated acids can be divided into several groups labeled with the well-known term omega. For example, omega-3 means that the first double bond appears on the third carbon from the end of the chain, omega-6 on the sixth carbon, and omega-9 on the ninth.

Monounsaturated fats contain one double bond, representing omega-9 acids. Generally, monounsaturated fats have a lower capacity for oxidation than polyunsaturated fats and are more stable under normal conditions.

Polyunsaturated

From a chemical viewpoint, they contain two or more double bonds. These include omega-3 and omega-6 fatty acids.

Trans fatty acids

This group of fats is being increasingly discussed in terms of health (increased risk of cardiovascular disease, increase in LDL cholesterol levels, etc.). Trans fats enter the diet in three ways:

1. Naturally - produced by bacteria in the digestive tract of cattle and sheep, and passed into milk and meat.
2. Artificially – through hydrogenation or hardening of fats (now often replaced by emulsifier technologies) – this process extends shelf life (prevents rancidity).
3. Through cooking - heating oils to high temperatures during baking and frying.

If we want to influence metabolic processes and the resulting level of health through diet by choosing fat-rich foods, the following rules should be respected:

1. Limit the overall amount of fats in the diet (on average, we consume them in excessive amounts, being one of the main causes of overweight).
2. Reduce most animal fats and preferably choose plant-based sources, ideally unprocessed (this changes the ratios of different types of fats and increases the nutritional quality of the diet).
3. Make these adjustments so that the ratios of fatty acid families (saturated, monounsaturated, and polyunsaturated) match not only modern standards based on scientific research but also individual metabolic needs (fats have the ability to affect the rate of energy production in cells, and by manipulating their amount in the diet, we can influence metabolic behavior).