How to speed up metabolism and lose weight? See what science says

One of the main trends today among those trying to lose weight is the search for ways to speed up metabolism, which would lead to greater calorie expenditure. On store shelves and on the internet, it is possible to find several thermogenic foods, substances and supplements that promise to enhance this process. But the truth is that none of this is really effective, as studies point out.

But, after all, what does it mean to “accelerate metabolism”? Nutritionist Dennys Cintra, a professor at FCA-Unicamp (Faculty of Applied Sciences at the University of Campinas), in São Paulo, explains that the term metabolism refers to the body’s expenditure of energy.

“We work thinking about an equation that translates the biological reaction of energy expenditure. In other words, we need an X amount of energy for the organism to perform a certain function”, he explains.

Metabolism is separated into two types: basal and total. The first is the amount of energy needed to perform vital functions. “Even a person in a coma consumes this energy. She is at rest, but her heart continues to beat, the other organs continue to function”, exemplifies Cintra.

Total metabolism, on the other hand, refers to the physical effort itself, both what is done by breaking a sweat at the gym and getting up to go to the bathroom at night. “We put energy in through food. If I spend more than I ate, I’ll lose weight. If I spend less, I’ll gain weight”, concludes the nutritionist.

However, this is not a 100% accurate account because the result also depends on the speed at which the metabolism works, something that is individual, as explained by endocrinologist Márcio Mancini, vice president of the Department of Obesity at Sbem (Brazilian Society of Endocrinology and Metabology).

“This is genetically determined. There are thin people who eat a lot of calories, but their body consumes a lot of energy in daily activities without them necessarily doing a lot of physical exercise. And there are obese people who don’t eat as many calories and exercise, but tend to gain weight. weight”, reports Mancini.

Metabolism also changes throughout life to adapt to the energy demand of each age group. This is why metabolism slows down as we approach old age, as energy expenditure is not the same as when we are young.

Do thermogenics help you lose weight?

We call foods and supplements with substances that are capable of accelerating our metabolic reactions, which increases body temperature and basal caloric expenditure, thermogenic. Therefore, they are sold with the proposal to help you lose weight by burning calories without you having to make an effort to do so. Green tea, pepper, ginger, omega 3 and caffeine-based supplements are some examples.

But scientific evidence shows that, despite actually accelerating metabolism, the energy expenditure offered by these items is not significant to help in the slimming process.

A review of studies published in the International Journal of Obesity showed that consumption of caffeine, capsaicin (a substance present in pepper) and teas such as green and white, increase energy expenditure by only 4% to 5%.

See: an adult weighing 80 kilos consumes, on average, 2,000 calories daily. 5% of this amount represents only 100 calories more, which is not effective to lose even a kilo on the scale.

There is even research with evidence that thermogenics work. “But the studies that reveal these benefits are done in cells or animals, not in people. This shows that the cellular mechanism exists, but not to a sufficient degree to induce weight loss”, reasons Cintra.

In addition to not bringing real benefits, these substances still pose dangers when consumed in excess. “Some thermogenic supplements, especially those with caffeine in the composition, end up leading to death from cardiac arrhythmia when the person uses a dose greater than the recommended one”, warns the endocrinologist.

Cintra cites a problem caused by coconut oil, which is widely consumed in recipes. “It is an important activator of the immune system. It is as if you induce a pseudo-infectious process in the body itself. It backfires. The effect of energy expenditure will be minimized in the face of this side effect”, he reports.

How to speed up metabolism

In the end, is something capable of accelerating our metabolism? And the answer goes back to the basic recipe for a healthy life: exercising, having a balanced diet and quality sleep.

Any type of physical activity accelerates metabolism as the body consumes energy by recovering tissues damaged during practice. But this will vary depending on the type, duration, and intensity of exercise.

A review of studies carried out by EEFE-USP (School of Physical Education and Sport of the University of São Paulo) showed that SIT training (sprint interval training) generates greater energy consumption after practice, when compared to continuous training such as HIIT ( high-intensity interval training).

In relation to food, the very act of digestion already causes metabolism to be activated. It is important to focus on maintaining a balanced and well-distributed menu throughout the day. This is more effective than investing in miracle diets.

“When an individual is on a highly restrictive diet, the body responds to it as if it were an attack and reduces energy expenditure. In other words, the drastic reduction in calorie consumption ends up slowing down the metabolism”, warns Cintra.

Finally, a good night’s sleep also contributes to the functioning of metabolism. When we get little sleep, the levels of leptin, a hormone that makes us feel full, decrease, leading us to eat more. And ghrelin, another hormone responsible for opening up the appetite, grows, influencing this result. In addition, during the night’s rest, the body expends energy. According to the Sleep Foundation, in the United States, 1 hour of sleep consumes about 50 calories.

Specialists emphasize that none of this can be taken literally, since the assessment of cases must be individual and the guidance of a professional is necessary.

“It is very important to know the history of each patient because they are completely different. We have to individualize both the diet and the physical activity proposed for them”, concludes Mancini.