Metabolism: what is it, what are its functions and how to support it?

The term "metabolism" comes from the Greek. The word metabolismos means "change", which perfectly describes the principle of this process in our organism.

Metabolism in the human body is an interplay of chemical reactions. They convert nutrients taken in the diet into energy, which our body uses to sustain its existence and ultimately our activity during the day.

What are the functions of metabolism and how it works, you will learn in this article.

Metabolism for life

The chemical reactions involved in the process of metabolism are almost identical in all living organisms - animals, plants, bacteria or fungi.

Our body takes in nutrients in the form of macronutrients such as proteins, carbohydrates and fats. It breaks them down into simpler substances by chemical processes. This process is called catabolism.

However, the body also works in the opposite direction. It creates complex products from simple substrates, for example building muscle mass, fat tissue, creating hormones, enzymes, etc. This process is called anabolism.

All these chemical reactions are mediated by proteins that act as catalysts under specific environmental conditions such as pH and temperature.

What processes consume the energy ingested in the diet?

Energy ingested in the form of food is consumed by our body in three or four processes.

The basic process is called basal metabolism, also called resting metabolism. This is the metabolism in which we burn calories without - as they say - lifting a finger.

This kind of metabolism keeps our cells alive and our whole body running. It ensures basic physiological processes such as breathing, heart function, brain function, etc.

Keeping our body alive is energy intensive. Basal metabolism consumes most of the energy we take in, about 60-70%.

However, this value depends on several conditions such as the temperature and humidity of the environment, gender, weight, height or age of the person.

Calculate your basal metabolic rate:
BMR - Calculator.

The second "combustion" process is the energy the body must use to digest, absorb and process actual energy and nutrient sources.

In order to get any energy at all from food, we must expend some calories to handle the necessary processes. This kind of energy is called the thermic effect of food.

The value of this component depends primarily on the properties of the food itself, its volume, the form in which it is ingested, its consistency and, last but not least, the macronutrients of which it is composed.

Most of the energy is consumed in the digestion of foods with a high protein content. About 10-15 % of the total daily calorie intake is used for this purpose.

The most variable component of our energy expenditure, which only we can influence, is our physical activity. For active people and athletes, this can account for up to 50% of total daily intake.

For less active and non-exercising individuals, it is approximately 20%. They too walk several steps a day, stand in the lunch queue or sit at the computer.

Yes, even these activities require energy in the form of calories.

Physical activity increases energy expenditure during the actual exercise, but the increased calorie burn persists for some time after exercise. This means that even if we are sitting comfortably on the couch after exercise, our body is still burning more than if we had been sitting on the couch all day without exercising.

Hypermetabolism is a metabolism with an accelerated metabolism in situations where our body has increased demands for energy and nutrient supply.

Hypermetabolism is common in high fevers, infectious diseases or endocrine diseases such as hyperthyroidism (increased thyroid activity).

Metabolism doesn't have to be fast. It just needs to be elastic!

Flexible metabolism has long been a well-known concept among professional athletes. It is an ideal way for any individual to improve their training and give their body plenty of energy from the best sources.

Textbook lore on flexible metabolism states that it is the body's ability to adapt fuel oxidation to its availability.

This means that the higher the level of glucose in the blood, the more the body uses it as an energy source. In the latter case, the higher the availability of free fatty acids or fats in the blood, the more they are used as an energy source.

It is the body's ability to switch between the two primary energy sources, glucose and fat, depending on their availability in the blood.

A metabolically flexible person is able to burn mainly glucose after consuming a meal rich mostly in carbohydrates. Conversely, he or she is able to burn mainly fat after consuming a fatty, sugar-poor meal or during fasting or exercise when blood glucose levels are low.

However, individuals with a truly high degree of metabolic flexibility push the boundaries of burning even further.

These individuals are able to generate energy exclusively from fat sources, even during strenuous physical activity, when blood glucose levels are high and muscle and liver glycogen stores are depleted.

The reason for this is to conserve carbohydrate sources during normal and moderate physical activity and to use them as an excellent and readily available source of energy only during periods of really very intense exercise.

The opposite is true for individuals with a low degree of metabolic flexibility. These people use only glucose as their main source of energy, even at very low training intensities. Their body is therefore unable to convert fat into ATP, i.e. energy. Therefore, it stores it.

To become a person with a high degree of metabolic flexibility, we need to increase the number of mitochondria in our cells.

Mitochondria are cellular organelles that we can think of as little "energy factories". Mitochondria convert oxygen and fuel obtained from macronutrients to produce ATP, or energy. In addition, they also produce metabolic waste, which is carbon dioxide and lactate.

Mitochondria owe their ability to aerobically burn oxygen. If we didn't have mitochondria, we would be doomed to anaerobic energy production. This is the way of life for unicellular organisms.

How do we increase the number of healthy mitochondria in our cells?

We can do this by training, increasing the proportion of muscle mass and changing the structure of fast muscle fibres, which naturally have a higher number of mitochondria per cell. By training, we can also increase the number of mitochondria in slow muscle fibres.

However, only people who have an adequate percentage of subcutaneous fat and muscle mass can achieve functional metabolic flexibility. Therefore, especially obese or thin old people are not predisposed to this type of metabolism.

In order to burn, we need fuel or calories

You've probably heard the cliché somewhere that regular dietary intake speeds up metabolism - the more you eat, the more you lose weight. In fact, there's a lot of truth to this.

In order for our body to burn energy in the form of calories, it has to take in those calories. When you supply your body with enough energy, all processes will work like clockwork. The process of burning, i.e. metabolism, is no exception.

If your daily calorie intake is too low, the body will become alarmed that it does not have enough energy to keep the cells viable. It will consequently try to put away and save a little energy from every meal you eat. Therefore, it will start to build up stores in the form of fat cells.

If you starve for a prolonged period of time, the body will start using protein from muscle mass as an energy source. The result is a hungry person who has abundant fat stores around the waist and zero muscle mass. And that's probably not the goal you wanted to achieve.

A regular caloric intake that consists primarily of protein, carbohydrates and healthy fats will jumpstart your metabolism and build muscle mass.

Muscles burn many more calories than other types of fibers and cells. The more muscle you have, the better you will burn the calories you take in. Your body will not store stores in fat.

However, dietary fat is not our enemy. On the contrary, healthy fat is needed by our bodies to carry out many important processes. Many vitamins are fat soluble (A, D, E, K), cell membranes are made up of fat, it has a protective function around fragile organs, etc.

Fat is the carrier of taste in the diet. It causes a greater sense of satiety, is the richest source of energy. Because it is not easily soluble in water, it naturally slows down metabolism.

The exception to this rule is fat, which is made up of medium-chain triglycerides (MTC).

This type of fat, on the other hand, speeds up the metabolism, does not burden the liver or pancreas, and improves tissue regeneration. Therefore, it is great to include in reduction diets, after physical activity, for gallbladder problems and digestive disorders.

Wise minds will be pleased with other information. MTC oil has been scientifically proven to support cognitive function and mental activity. Examples include coconut oil and various dietary supplements.

Tips and habits for boosting metabolism

Sometimes we just need to give our metabolism a kick. Check out these dietary tips or habits that may help.

Spice it up!

Some spices can increase the thermic effect of food. The plus side is that you can spice up your food without increasing your calorie intake. For example, adding chilli or hot peppers can boost fat burning. A substance called capsaicin is responsible for this.

Black pepper, turmeric, ginger or cinnamon have a similar effect. Cinnamon doesn't just have to be added to sweet dishes, it can spice up beef dishes too.

Ubiquitous fibre

This is what your plate should look like. Every daily meal should contain a high-fibre food.

Fibre is an insoluble polysaccharide. This means that our bodies cannot consume or digest it. That's why it passes through the entire digestive tract. It brushes, cleanses and promotes the movement of food in the intestines.

Even if the body doesn't absorb the fibre, it still tries to. This burns energy and calories.

In addition, it has a large volume without caloric value, so it keeps us full for a long time. We don't gain weight. On the contrary - our body keeps working hard to "process" the fibre, so to speak.

Foods rich in fibre are legumes such as beans and lentils, various seeds such as flaxseed, vegetables and fruits with skin or avocados.

Hydrate yourself!

It's not for nothing that they say water is the basis of life. Every cell in our body is made up of water and uses it to perform its functions and in the metabolism of nutrients.

Water also fills your stomach so you feel fuller and skip the small snacks between main meals. In addition, water intake increases fat burning - lipolysis.

However, it is important to hydrate yourself with plain unsweetened water or herbal tea without added sweeteners.

How much water should I drink per day?

Morning coffee or tea

For many of us, the morning cup of coffee is a ritual we can't start the day without. However, few people realise that coffee can also kick-start our metabolism!

On the plus side, caffeine's ergogenic effect improves performance, strength and speed. For this reason, coffee is a popular and allowed pre-workout dope.

For those who prefer to use their head rather than their muscles, we also have good news. Coffee has nootropic properties. This means it improves cognitive function, deepens concentration, focus and blood flow to the brain.

If you don't like the taste of coffee, try green tea. It's a good nootropic and also a metabolism booster.

Tea contains not only caffeine, but also other plant components that have antioxidant properties. These include plant catechins and epigallocatechin gallate, which are also available in various dietary supplements.

Lots but varied exercise

Movement is the alpha and omega of a healthy body, burning and fast metabolism. Of the many movement activities, the best for burning is so-called high-intensity interval training - HIIT. The principle of this high-intensity training is that your body burns calories long after the workout is over.

It is ideal to alternate aerobic exercise with strength training. Muscle fibres burn many more calories than fat tissue. Therefore, by gaining muscle mass you increase your body's energy turnover.

If after some time of training you feel that your body is not changing and stagnant, you need a change.

A change in training will cause your body to adapt to something new. It will have to put in increased effort and work harder. And it is the change in routine and stereotype that is the key to making progress.

Treat yourself to quality sleep

Rest and recovery are even more important than the training itself. During sleep, the regeneration mechanisms of cells and organs take place, all the important information is stored in the brain, cells get rid of waste substances and the whole body detoxifies.

A tired body cannot function properly during the day, all processes, including metabolism, slow down. Moreover, lack of energy subconsciously forces us to eat and replenish energy, especially in the form of carbohydrates, i.e. sweets.

The ideal is to allow yourself 8 hours of sleep every day with a large proportion of night sleep. This is the one that lasts until midnight.

Sleep hygiene: 10 simple rules for quality sleep

Intermittent fasting

This modern way of eating or dieting has been subjected to various scientific studies by scientists. They have shown that fasting every other day for two months can reduce LDL cholesterol and triacylglycerols (the so-called bad cholesterol).

A study of glucose levels was equally successful. After eight weeks of intermittent fasting, a decrease was seen in healthy people, obese people and diabetics.

Even in people with type 2 diabetes, the sensitivity of cells to insulin, which helps carry glucose into cells, increased.

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