6 Answers

  1. During the day, your body spends about a quarter of its energy on the work of your brain. Now a minute of math. If you don't do any sports, a woman burns an average of 1,000 calories a day, while a man burns 1,500. That's how many calories your body needs to keep you breathing and functioning. This means that a woman's brain requires an average of 250 calories a day, while a man's brain requires an average of 375 calories.

    And here's what's important: if an athlete, unlike a person who likes to lie on the couch like a sack of potatoes, can spend both 3000 and 6000 calories, the brain will still not burn more than its 250 (for women) and 375 (for men). 250 calories (and 375, respectively) is his limit! He doesn't need any more, and he won't spend any more.

    From the fact that you will think a lot — you will not burn a single extra calorie. Sometimes you hear someone say, ” Oh, I've been thinking so hard, my brain must have consumed so many calories, I'm going to get a chocolate bar to eat.” Nope, your brain hasn't burned any extra calories, it's just that you've been stressed out by intense mental stress and now you want to eat it sweet to make you feel better.

  2. In my personal experience, I say that increased mental activity contributes to greater calorie burning. Moreover, the dependence is directly proportional. Look at people who, under constant stress, lose a few pounds in 2-3 days. With the same diet, without physical exercises, but with strong mental loads, my weight kept exactly the same as with strong physical exercises with no mental ones. And it fell very much when they were combined. The brain eats well. And it doesn't have any limit.

  3. Yes, another article with mythology for those who have forgotten elementary school physics – the law of conservation of energy. Energy from food or stored reserves of the body can be converted either into useful work or into heat. During sleep, the temperature drops, the heartbeat and heat exchange with the environment slows down – energy consumption per unit of time is minimal. During wakefulness, energy consumption for maintaining body temperature and basic vital functions (including maintaining consciousness) increases, and the cost of movement/work is added. But the work must be physical. When preparing for the exam, work in the physical sense of increasing body temperature is usually not noted, so there is no need to talk about any” calorie burning ” from mental exertion.

  4. The human brain, even in a state of relative rest and sleep, consumes an extraordinary amount of energy-16 times more than muscle tissue (in terms of unit mass). “The brain, having a mass of no more than 1.5—2% of the body weight, consumes 25% of all energy. At the same time, one of the most energy-intensive operations is concentration of attention. A person is not able to keep attention at a consistently high level for more than 20-25 minutes, because during this time the brain will “eat” as much glucose as it would not eat in a day of relative rest. So tasks for attention and reaction, and even in a situation of time pressure, can squeeze out all the energy, — said Igor Lalayants, Candidate of Biological Sciences, employee of the Institute of Neurosurgery of the Russian Academy of Medical Sciences. – The need for energy decreases only during sleep, because synchronization of the left and right hemispheres increases and the brain does not have to spend energy on “coordination” of their work. Neurons also reduce energy consumption with age, which slows down the synthesis of protein molecules and, as a result, worsens the ability to remember.” In an adult, brain metabolism accounts for 9% of the total energy requirements of the body during sleep and 20-25% during intense intellectual work, which is significantly more than in other primates (8-10%), not to mention other mammals (3-5%). So, only to maintain the necessary vital functions, transmit nerve signals and reproduce elementary operations, the human brain on average needs about 400-500 kcal. Meanwhile, according to the most conservative estimates, the energy expenditure of the brain in the active state increases more than twice. “The part of the brain that is most stressed consumes the most energy. Therefore, when solving multi-part tests and puzzles, where all types of thinking are involved in turn, energy consumption increases dramatically. You will also have to spend more calories on unusual tasks. So, if you force a humanist to solve a geometry problem, the energy consumption of his brain will greatly increase. However, not everyone can bring themselves to the degree of physical exhaustion by mental exercises. As a rule, scientists, mathematicians, and chess players have such a reaction to mental work, ” explained Alexander Revishchin, PhD, Senior Researcher at the Institute of Developmental Biology of the Russian Academy of Sciences. In addition, intellectual work is necessarily accompanied by activation of the nervous system and under the influence of emotional experiences, energy costs increase by 10-20%. And unusually large intellectual loads, coupled with the stress that accompanies any exam or testing, according to the Russian Academy of Medical Sciences, increase the body's energy consumption by all 30-40%. So, scientists from the P. K. Anokhin Research Institute of Normal Physiology of the Russian Academy of Medical Sciences calculated the energy consumption of 75 students a few days before the exam and directly during testing. It turned out that the need for calories increased as exams approached, and if three days before day “X” a student spent about 750 kcal in excess of the basic exchange rate, then on the day of the exam — 1000-1100 kcal.

    source: rbcdaily.ru

  5. I'll tell you for myself. I have traveled many times by car (driver) from Moscow to Izhevsk and back. This is 1200km. I often traveled in one day, without spending the night. I left at 5-6 in the morning and arrived at 22-23 in the evening. I only stopped at gas stations. For one such stage, I lost 1-1. 5 kg in weight. According to my calculations, calorie expenditure was 2000-2500 a day. I arrived very tired, my eyes hurt wildly. Working as a driver is a complete lack of physical work, you sit in the driver's seat, twist the steering wheel and step on the gas. Everything! All the work of the brain. Sharpens attention, a large load on the eyes. That is, this is an example of mental work . And my answer is: yes, the brain still spends calories!

  6. Unfortunately, I am not an expert in this field, but it seems to me that James Painter's argument is not logical.

    Brain function is work. The development of nerve impulses and others like it. It is difficult for me to judge here, but I assume that in the state of general metabolism(when a person is lying down, relaxed and has not yet eaten), the brain “does” less work, that is, it “eats” fewer calories. After all, if the brain simply “supports” life, and does not rush around in a panic and try to save its owner from a crocodile or help him not to embarrass himself at a meeting, it should produce fewer nerve impulses, and therefore do “less” work.

    So the thesis about a strictly defined number of calories and their limit seems doubtful to me.

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