What Is Metabolism and How It Works?


So let's try to understand better what metabolism is, by clarifying how it works. Here is everything you need to know about this process that is so important for your fitness and in particular:

What is metabolism?

In Greek, metabolé means “change.” The metabolism of a substance is simply the chemical transformation of the substance into something else. Thus, if at the cellular level, sugar is transformed into energy, we can say that a "metabolism" takes place. 

The metabolism is, therefore, the set of chemical reactions that take place in your body - and the hormonal regulation of these reactions - to transform the food ingested into the energy needed by the cells of your body. An energy that is used by the body to make cells work properly and to keep us alive.

How does it work?

This set of metabolic chemical reactions takes place continuously in our body through two essential processes: catabolism and anabolism.

Catabolic reactions

Catabolism is also called “destructive metabolism "because it consists of the decomposition of the molecules introduced with food into others more easily usable by the body.

In particular, macromolecules, such as lipids, proteins, carbohydrates (but also vitamins, mineral salts, and all other substances) are degraded to produce energy, simpler molecules that perform other functions or to be recycled.

Anabolic reactions

Anabolism processes these recycled parts, giving them a plastic and energy reserve function.

In other words, anabolism has the task of growing organs and tissues, restoring them in the event of destruction or a simple replacement, and of storing the molecules and depositing them. This "reserve" means that there is always enough energy to allow us to cope with the efforts and to allow the cells to develop properly.

Furthermore, this reaction also has the function of conserving and optimizing the energy that can serve us in the future.

What is metabolism for?

This complex system of reactions is very important both for your health and for managing your body weight. In fact, it is basically the metabolism that determines the diet to be followed and the physical activity to do, in order to reach the desired healthy weight. it is necessary to make a further distinction between the basal one (also called BMR) and the one linked to the activity carried out by the individual (energy metabolism) to assess the correct functioning of your metabolism.

Basal metabolism

When we talk about BMR, we refer to what your body consumes in conditions of absolute rest. To be more precise, the basal metabolic rate represents the minimum amount of energy needed by the awake subject, but in a total state of rest, to maintain his vital functions (breathing, circulation, digestion, etc.). It is usually calculated after a fast of at least 12 hours and in a moment of total relaxation both physically and psychically.

This energy expenditure that, in a healthy and sedentary adult, represents about 65-75% of the total is mainly attributable to the activity of the lean mass that is to the muscles and internal organs, in particular, the brain, liver, kidney, and heart.

Normally in men, the lean mass is greater than in women, while for all of them, there is a progressive reduction over the years. Furthermore, there is great variability from one person to another. This means that for the same number of calories introduced, someone may tend to gain more weight than another.

This is because the basal metabolism is genetically determined by several factors such as:

- the sex is higher in men

- age: old age is slower compared to adolescence

- Other hormonal factors that can characterize the phases of life.

Energy metabolism

It is determined by the physical activity you do every day and by food-induced thermogenesis. So, from the work you do to move the body, make the different movements or lift a weight and from the energy consumption necessary for the digestion, absorption, and metabolism of the foods taken. It is always a percentage of energy consumption lower than that of the basal metabolism unless this is not increased with a ' very intense sporting activity.

It should also be considered that every physical activity has a particular energy cost, which affects your daily caloric requirements in different ways.

The evaluation of energy metabolism must be done keeping in mind some factors, such as:

- the intrinsic energy cost of the activity

- the time required to carry out the activity

- The size of the individual who carries out the activity.

The energy consumption for the same activity becomes higher, the greater the intensity, the speed, and the time of its execution.

How does energy metabolism work?

There is a link between exercise intensity and fat or carbohydrate (sugar) consumption.

The main factors that determine what will be used by the muscles during exercise are:

1. the type of exercise: for example if it is continuous or intermittent

2. duration

3. The intensity

4. Training status

5. The diet that is followed

6. The physical state of the person: for example, some diseases, such as diabetes, can change energy use.

In general, we can say that in the case of low intensity and short duration physical activity, the body will equally draw the energy it needs from fats and carbohydrates.

When physical activity is of low intensity, but of a longer duration - at least an hour -, the body will tend to burn more fat, which will cover the energy demand almost 80%.

How to speed up the metabolism

The basal and energy metabolism together represent the total of your energy consumption, that is, what your consumption is during the day.

In a correct diet, this total must always be the same or, if you want to lose weight, exceed the caloric requirement introduced with food.

That's why slow metabolism is one of the challenges for those trying to lose weight. Very often, it is to this disorder that you blame it if the balance needle does not go down. The solution you find most often is to reduce calories as much.

If you feed yourself little, you can't afford to consume your energy reserves, and when your metabolism slows down.

Low- calorie diets that tend to produce rapid weight loss consume fat, but also muscles, that is, lean mass, which most influence the change in basal metabolism. For this reason, often these fast weight losses are followed by rapid increases as soon as you start eating again.

The right habits to get it moving again

It is enough to adopt some simple and healthy habits to speed up the metabolism, also restarting the slimming process correctly.

Eat slowly

The first digestion takes place in the mouth. If you eat too fast, in fact, don't chew the food properly, swallow air and experience greater digestive difficulties. In addition, you assimilate food worse and tend to swell and get fat.

Eat often

A strategy to reactivate the metabolism can be to eat little and often. Above all, to break the hunger between one meal and another, crunch vegetables that helps you keep fit, stimulating the metabolism and keeping the sense of hunger at bay.

Eat in various ways

It is important to learn to eat not only in terms of nutritional quality but also in the ways. You have to eat everything, but in the right balance expected from the food pyramid of the Mediterranean diet, distributing the meals correctly in 5 small daily portions.

Foods that accelerate the metabolism

It is not correct to rely on the choice of certain foods rather than others to speed up the metabolism because few foods do it and, in any case, always in a relative manner.

Among these, we can mention foods rich in iodine, such as fish or shellfish, because this element helps thyroid function.

Coffee, chocolate, green tea, and guarana can make a minimal contribution to accelerating metabolism. At the same time, however, an excessively rich diet of these foods can be counterproductive, that is to cause effects contrary to the original objective of wanting to maintain a good state of health.

A smart choice is to consume them in a balanced way, alongside fruit and vegetables, preferably fresh and in season. It is also important to choose foods that are as natural and integral as possible and avoid, or at least reduce, those that contain refined carbohydrates, hydrogenated fatsMetabolism, and simple sugars.The same goes for alcohol if consumed in excessive quantities could stimulate fat accumulation mechanisms and thus influence your metabolism.


1382 Words


Jan 16, 2020


3 Pages

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