Question to the expert: Is it possible to speed up the metabolism
Olga Lukinskaya
RESPONSES TO THE MAJORITY OF US QUESTIONS we used to search online. In the new series of materials we ask such questions: burning, unexpected or widespread - to professionals in various fields.
If the senselessness and danger of severe restrictions and mono-diets are obvious to many, then “scientifically based” diets often look seductive. All have learned that extreme restrictions can lead to a decrease in metabolism - the more attractive ways to “speed up” the metabolism seem to be, switching to certain foods, taking supplements or simply eating small amounts, but often. Do these methods work? Is it possible to make the body burn more without changing the physical load? We asked these questions to the expert.
Elena Motova
Diet doctor at the Dawn Clinic, author of the book My Best Friend is the Stomach. Food for Smart People, and a blog about evidence-based medicine
Our body works as a laboratory in which the processes of disintegration, destruction - catabolic reactions, and the processes of synthesis, construction, accumulation - anabolic reactions. They are subject to the influence of catabolic and anabolic hormones, are in dynamic equilibrium and together constitute the metabolism - metabolism. If to simplify, the metabolism is a series of chemical transformations in each cell, thanks to which the food we eat is converted into energy.
That part of the energy we receive, which is spent on the work of internal organs and systems, refers to the main exchange: this is the largest expenditure item - 50-70%. Energy is needed for the brain to think the liver has neutralized poisons, the kidneys have filtered urine. It turns out that we spend most of the energy without doing anything specifically for it. The main exchange occurs autonomously - regardless of our will and consciousness.
We also expend energy on the digestion and absorption of food - this is called the thermal effect of food, it accounts for about 10% of the total amount of energy received. Energy consumption depends on the composition of food: the least calories are spent on the absorption of fat, most of all - on protein foods. The third component of the energy budget is physical activity. This is not only a sport, but also, for example, maintaining a posture - absolutely everything we do using muscles. This is the most variable indicator - 10-30%, and in athletes and people engaged in hard physical labor, even more.
At the same time, the main exchange in different people is not the same: if you collect a dozen people who live on 2000 kcal per day, then their main exchange can be from 1000 to 1400 kcal. This (or even more) gap depends on various factors, including the activity of thyroid hormone thyroxine, which regulates the basal metabolic rate, and also on the surface area of the body (the greater the height and weight, the more energy is needed) and the ratio of muscle and adipose tissue in the body. Metabolically active tissues — muscles — need more energy. In women, the basal metabolic rate is lower than in men, and this cannot be explained only by a higher percentage of fat; in the second (luteal) phase of the menstrual cycle, basal metabolism is usually more active.
In addition to thyroxin, there are other molecules that affect the basal metabolic rate: in particular, stress hormones make us spend energy more actively. With age, the basal metabolism slows down by a few percent every ten years - partly due to the fact that a person becomes less mobile and loses muscle tissue. With a lack of calories during the diet, the body adapts to the energy deficit, also reducing basal metabolism.
Fat-burning supplements do not work: it is impossible to introduce a substance into the body that is able to break down fat molecules in adipose tissue and remove them
When they talk about speeding up their metabolism, it is usually proposed to do this either with the help of certain foods or by changing their eating habits - for example, switching to a fractional diet. The idea of the latter is that a large number of meals "accelerates" the metabolism, since more energy is spent on its digestion and absorption - the very thermal effect. But in fact, there is no difference how much energy is expended on the thermal effect with a different number of meals, if its total intake will be the same. You can increase the thermal effect by consuming more calories, but is it necessary?
Some foods, like chili peppers and coffee, may slightly increase metabolism (and understand the mechanisms of their influence on fat oxidation and thermogenesis), but their effect is so small and short-lived that it does not affect body weight or volume in any way. The advertising of "metabolic rate-increasing" products and supplements relies on questionable, poorly conducted and paid for by manufacturers of dietary supplements research. Numerous supplements that are positioned as "burning fat", in reality, simply can not work: it is impossible to introduce into the body a substance that is able to break down fat molecules in adipose tissue and remove them. In addition, these supplements have undesirable effects on the liver - and some unlucky slimmers in the US have brought them to the transplant department. Ephedrine supplements are generally prohibited by the US FDA: according to a 2003 meta-analysis, they have psychoactive effects and adversely affect various systems, including cardiovascular.
Dietary supplements are not tested for safety, like drugs. They are not able to accelerate anything (except for the expenditure of money), but they can additionally contain strong laxatives and diuretics, as well as prescription drugs for the treatment of obesity, which are prescribed according to strict indications and are taken under medical supervision. These components may not be indicated on the labels at all.
The only way to gradually increase the basal metabolic rate is to increase the volume of metabolically active tissues. More energy is spent on muscle maintenance, so its consumption will increase a little. But the magic, fast and at the same time safe means to increase metabolism does not exist. As in everything that relates to the human body, the basic principle should be “do no harm” - that is, do not starve, do not try hard food restrictions and “fast” diets on yourself. Extreme diets force the body to turn on economy mode in order to more efficiently use incoming food. Basal metabolism slows down, the synthesis of signaling molecules that control feelings of hunger and satiety is changing.
While reducing weight, some reduction in basal metabolism is logical, because you need to maintain the vital activity of a smaller amount of tissues (although adipose tissue accounts for a little, 3-4% of the energy of the basal metabolism) - but with extreme diets this decrease exceeds the expected one. This leads to an interesting phenomenon: the body resists weight loss with all its might, but easily returns it. That is why in evidence-based dietetics there are no simple, easy and quick solutions.
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