Like karpov, extreme physical changes caused by chess are not uncommon. Although no one else has experienced such a drastic weight loss, according to ESPN, a famous sports media, elite athletes once burned more than 6,000 kilocalories without leaving their seats in one day.
Is the brain the main reason why humans consume a lot of energy? Can thinking hard make us lose weight easily? To answer this question, we must first know how much energy an ordinary brain that is not addicted to chess needs to consume every day.
When our body is still and only maintains basic breathing, digestion and body temperature, the body supplies 20%-25% of energy to the brain. These energies are mainly consumed in the form of glucose. For women, this means that the brain will help us consume 350 kilocalories every day, while for men it is 450 kilocalories.
Children's brains are hungrier. Doug Boyer of Duke University is an associate professor of evolutionary anthropology, who mainly studies the anatomy and physiological changes of primate origin. He said that children aged five or six use more than 60% of the brain's energy every day.
This "sugar-addicted maniac" habit makes the brain the most energy-consuming organ in the body-although its weight only accounts for 2% of the total body weight.
The human brain is not special in the matter of "sugar addiction". Professor Boier and Arianna Harrington, a doctoral student in evolutionary anthropology at Duke University, conducted a study together. They found that small mammals such as tree shrews and bonobos provide a lot of energy to the brain just like humans.
Boier believes that for humans and these animals, although the brain is light, it is relatively large compared with other parts of the body, which is why it is "sugar-loving". Boier told us in an interview: "If your brain is very large relative to your body size, it is likely to consume more energy from a metabolic point of view."
Most of the energy consumed by the brain is used for communication between nerve cells in the brain. Harrington said that this process needs to consume a lot of energy. It needs to trigger a cell structure called synapse to transport many ions between cell membranes-and transporting ions across the membrane is one of the most energy-consuming processes in the brain.
Besides, the brain has never really rested.
When we sleep, the brain continues to "burn" endlessly, transmitting signals between cells to maintain body functions such as breathing, digestion and body temperature. In order to keep the brain working normally, supporting cells need to continuously deliver nutrients to nerve cells. These cells all need to use glucose in the body to maintain their own survival and complete their mission.
A lot of resources are also needed in the process of brain development, which explains why the brain consumes almost three times as much energy as adults at the age of five or six.
Since the brain is an energy glutton, does this mean that if we let it work more, it will consume more energy and we will burn more calories?
Theoretically, when the brain is performing some complex tasks, the answer to this question is yes.
Different people have different standards for "complexity". Claude Messier, a professor of psychology and neuroscience at the University of Ottawa, believes that complex tasks generally refer to "tasks in which the brain cannot easily use previously stored knowledge, or tasks with changing conditions", such as learning a new musical instrument or stepping out of novel footwork in a fierce chess game.
Messier said that when learning new knowledge and skills, the brain will correspondingly activate some brain regions and increase energy consumption. As our newly acquired skills become more and more proficient, the brain will no longer need to work as hard as it did when it first learned, so it will eventually consume less energy.
In this case, when we are just beginning to learn some tiring tasks, can we eat more snacks with high sugar content in order to replenish energy?
Of course, if you just need candy to make yourself more excited. However, if you think that the process of deep thinking will make you consume that dessert, then unfortunately I tell you-no.
Behind the invisible scene, the brain consumes huge energy for multi-dimensional work; In contrast, we think hard and consume very little energy. Messier explained: "Most of the energy consumed by the brain is actually used to supply invisible and unconscious activities; Moreover, these activities have nothing to do with our conscious behavior in Dachuan (such as learning to sing or learn to play the guitar). "
In other words, learning a new skill or doing something complicated is not the most energy-consuming part of brain work. Messier added: "In fact, when we learn new knowledge and new activities, the energy that the brain puts into these' new things' is actually very small compared with other total energy consumption of the brain."
Harrington explained: "The brain can transfer blood and energy to some specific areas that are currently active; But in general, the energy available to the brain should be relatively constant. " Therefore, although we carry out some complex thinking activities, there will be a peak of energy consumption in some areas of the brain; But compared with the total energy consumption of the brain, these activities will not cause obvious changes.
In this case, how to explain karpov's thinness in chess? The current understanding is that this is mainly due to the pressure brought by the competition and the reduction of food intake, rather than mental consumption.
Chess players are under great pressure and will be nervous, which will lead to faster heart rate, faster breathing, sweating and burning calories. Besides, sometimes players have to sit for eight hours in a row in order to compete, which will also disrupt their normal diet. Similar energy consumption is also common among stage actors and musicians, who are often under high pressure and their eating habits are often disrupted.
Messier explained: "Being physically active for a long time is a very energy-consuming thing; If you can't maintain a normal food intake at this time, you may lose weight. "
So, the conclusion is-unfortunately, thinking itself can't make us thin. But the next time you are not inspired, it doesn't hurt to eat an extra chocolate.