What kind of energy do scientists use

Does thinking make you slim?

by Kristina Abels

It is the organ with the highest energy consumption: our brain. So strenuous thinking should lead straight to the ideal figure. Or not? A psychologist explains the exact relationship between the head and the stomach.

This is how it looks, the typical student life during the exam period: mountains of books, stacks of paper, in between a bitten apple, a bar of chocolate, a hot laptop and somewhere in the middle of it the eagerly studying student. Cramming and thinking from morning to evening until your brain overheats. There is no time for jogging. The stressed test object therefore not only eats knowledge, but also a chocolate belly - at least that's what you think.

Can the pounds drop while thinking?
Photo: Peter
In fact, the opposite is often the case: Many people drop pounds while studying. How can that be? Does hard thinking make you slim? That would be it: Instead of starving and sweating towards the desired weight while exercising, we will simply think thinner in the future! After all, the brain is the organ with the highest energy consumption. It weighs just two percent of the body weight, uses around 20 percent of the total energy and could therefore glow as brightly as a 25-watt bulb.

The brain knows no breaks

From a scientific point of view, however, it doesn't work. “We don't get thinner through hard thinking,” says Ursula Reichwald. The qualified psychologist is a lecturer in clinical and biological psychology at the University of Tübingen. The explanation: The brain hardly consumes more energy during top sporting performances than when it is “at rest”. It doesn't actually know him at all. In fact, our thinking organ never pauses: “Even when nothing is going on, the brain knows what to do. When there is a lack of orders, it thinks up something for itself. ”Daydreams or even misperceptions such as hallucinations are an example of this.

Sensory impressions such as smells or touch have to be processed and behaviors coordinated - even during sleep. It is thanks to our brain that we can dream quietly at night without falling out of bed. Around 100 billion nerve cells, the neurons, are available for all of these tasks. They are linked by around 100 trillion synapses that transmit information in the form of electrical signals from one neuron to another.

With the help of imaging methods such as functional magnetic resonance imaging (fMRI), scientists can now observe how the metabolism and blood flow in the brain change. By applying strong magnetic fields, fMRI can recognize special areas of the brain in which oxygenation occurs. The reason for this is an increased blood flow in the places where there is particularly strong commemoration.

Most of the energy - 60 to 80 percent of body fuel - is consumed by the communication between the neurons, which always takes place when the brain is switched on: not only when philosophizing and discussing seriously, but also when fooling or laughing, even when sleeping. Less than one percent goes into processing external sensory impressions; this also includes reading difficult texts, for example.

With such a small additional consumption, it takes a comparatively long time to use up the bar of chocolate that you have devoured with the thick textbook by simply exerting your brain. Instead of pedaling for two to three hours on the bike, you have to show a lot more thoughtfulness - after around thirty-two hours the little calorie bomb (600-700 calories) would only be gone! Ergo: Thinking is not a means to slim down.

Just don't think about food!

If you think, you get slim - but that could be true if thinking means thinking. After all, every diet is preceded by the cognitive decision to slim down - and thus to actively control food intake. But appearances are deceptive: Experts warn against interfering with eating behavior; because our body unconsciously does it right on its own if you don't disturb it. "Thinking does not make you slim, it can indirectly make you fat!" States Reichwald and warns: "Any intervention in the food balance is the first step towards obesity or anorexia."

Graduate psychologist Ursula Reichwald from the University of Tübingen. Photo: private
The fight against the dreaded yo-yo effect only wins about five to ten percent of dieters. The others rock their way up in a kind of continuous spiral between losing weight and gaining weight in the direction of obesity. Because as soon as the body has to get by with less energy than usual, it switches to the back burner: The food that still comes in is processed particularly effectively - a mechanism that is essential for survival in times of actual food shortages. This strategy is not given up anytime soon, even if there is enough to eat again.

A recent study from the USA clearly shows that it is best to keep your hands off your food balance: Even healthy, normal-weight people can quickly slip into the described savings cycle: The test subjects received 400 calories less than the control group. A feeling of hunger does not arise, and yet: on the third day, the brain cannot help but deal with the food that was withheld from it: “You dream of steaming potatoes and hot sausages,” says Reichwald, describing the reaction of the thinking organ.

It works best automatically

This effect can also be observed in children. Girls in particular are concerned with their weight - and gain weight! Because our brain works differently than we do. For example, if I decide not to have chocolate tonight, all my brain can hear is “chocolate”. The context of the content doesn't matter to my cells in my head. The hint is enough for you to trigger my urgent desire for chocolate!

So if you want to stay slim or lose weight, you shouldn't even think about it - at least not about food. All those who manage to do this without thinking too much: to eat when they are hungry and to stop when they are full is what science calls automated eaters. People like her automatically stay slim. The so-called controlled eaters have to think actively and constantly pull themselves at the belt.

But if thinking does not make you thinner, you have to do something different. The offer is huge and confusing. Dubious promises such as "Get your desired weight at the click of a mouse - lose weight on the Internet" give the impression that you could lose pounds at the push of a button. The latest craze is hardly more serious, the low-fat diet, the effectiveness of which has not even been proven. "The Brigitte diets are most likely to prove their worth," says Reichwald. Because this is about long-term and above all frustration-free weight loss, not about spontaneous starvation diets.

Other dubious miracle diets are the so-called Glyx diet or - for fans of juicy meat - the low-carb diet. According to the motto meat enough! Fat and protein are allowed in large quantities, carbohydrates are prohibited. Malnutrition including unpleasant consequences such as bad temper or even gout is inevitable.

Formula diets have a gray sip instead of a real meal - a monotonous affair that doesn't even teach you what a healthy diet means. And that's actually the core of it all! The popular eat-in-half method does not achieve the goal either. Half of the wrong is still wrong.

There is no slag at all

And fasting? The only thing you gain from this is perhaps clear thoughts and the insight that only healthy nutrition can lead to lasting success! In the case of radical non-eating, it is mainly muscle mass, not fat, that is reduced. And there can be no question of purification: “There is no such thing as slag at all! Nothing is deposited in the body, ”explains Reichwald, who also trained in nursing and physiology before studying psychology and today, in addition to teaching and research, writes expertise for insurers and health insurance companies.

The psychologist shares her attitude with the German Nutrition Society. Because even they don't believe in the slag fairy tale: The end products of metabolism are excreted via the kidneys, intestines, lungs or skin. Nothing remains in the body.

The only exception is hash in the brain: THC, the active ingredient in cannabis, is deposited in fat cells. But THC can hardly be flushed out of the body through fasting.

Getting slim is not an easy matter in the truest sense of the word. To make matters worse, with the armies of plump people, the genetics are 50 to 60 percent to blame for the insatiable fat cells. Those who have slim growers can consider themselves lucky.

But they shouldn't be too slim either! Because then it can just as well happen that the path to obesity is paved before birth: In the case of fetal food deficiency, which occurs when the expectant mother does not eat well or generally has too little on her ribs, the new organism learns particularly well effective processing of the meager food. Once the child is born, it tends to become obese due to its highly functioning savings mechanism.

The desk criminals

Nevertheless: If it is not thinking that makes you lean, how can you explain that academics are usually leaner than less qualified groups of people? In fact, body weight is not only due to hereditary predisposition, but also depends on social class and lifestyle. The pressure from the environment does the rest.

Back to the student desk: Why are not only thoughts falling here, but also the pounds of some, and all that without exercise? Thinking does not lead to a leaner figure. Fear and tension only increase the basal metabolic rate.

The explanation is simple: some exams stressed students forgets to eat because of all the studying. It is lucky that the body balances this out all by itself and gains weight again after the many exams!