Cognitive activities can burn energy inside the body, but that alone is not enough to impact our overall physique.
You might find yourself sitting idly by the window, staring off into the distance, seemingly doing nothing at all, but did you know that even then, your body is continuously burning calories? You read that right! Our bodies are constantly burning calories, even if you are just sitting alone on a chair, allowing your mind to wander. Surprising, isn’t it?
Diving deeper, it is the human brain that continuously consumes calories even when we are not physically active. But how does this happen? To understand this phenomenon, let’s explore how the brain works.
The Brain: “The Energy-Hungry Being”
The brain accounts for only 2% of body weight but consumes 20% of its energy.
The brain is the central organ of humans, responsible for maintaining all life functions and is isolated from the rest of the body. It is well-protected by a sturdy skull and hard meninges. Although the brain only makes up 2% of body weight, it consumes a staggering 20% of energy. Most of the energy the brain receives comes from the breakdown of glucose – its preferred “food.” Blood continuously supplies glucose to the brain, as the brain itself cannot store glucose.
So, what does the brain do that consumes so much energy?
Discussing the various functions of the brain is akin to talking about every drop of water in the ocean! The human brain operates continuously, even while we sleep. Different regions of the brain have various functions, and their simultaneous coordination results in specific outcomes. Even at its most idle state, the brain is still quite busy.
Neurons are always “at work” to keep us alive and require a substantial amount of energy to transmit impulses. The brain remains active as it manages a range of human actions such as receiving stimuli, sending feedback signals, monitoring involuntary activities, maintaining homeostasis, and continuously communicating with the body’s internal organs. All these activities require a minimum amount of energy known as the basal metabolic rate.
When you are sitting and pondering a complex issue or trying to calculate how much money you need to save for a new smartphone, the number of calories your brain burns during such stressful moments will increase.
How Does the Brain Utilize Energy?
The brain uses about 300 calories per day to keep everything in check. Cognitive activities such as learning, thinking, and calculating can increase the metabolic rate within the brain and surpass that baseline level.
Numerous studies are ongoing to understand how the brain utilizes energy. Researchers using neuroimaging techniques have shown that the glucose metabolism rate in the brain increases by approximately 10% when subjects perform the Wisconsin Card Sorting Test (a type of neuropsychological test). This increase in glucose uptake during the test is accompanied by enhanced blood flow to the brain.
On average, the entire brain consumes about 0.25 calories per minute. (Illustrative image)
The test requires participants to classify each card based on the number, shape, or color of the characters on the card. The feedback will assess whether the card classification is correct or not. Based on this, participants can better understand the classification pattern. Furthermore, after 10 cards, the classification criteria will change.
In more detailed studies, scientists have attempted to quantify the number of calories the brain consumes. It was found that, on average, the entire brain consumes about 0.25 calories per minute. Cognitive activities are believed to increase the total brain metabolism by about 1%. These figures are approximate and can vary. Therefore, research to determine precise data is still ongoing.
So far, there is some evidence suggesting that performing complex tasks such as learning a new language or doing calculations can increase the brain’s glucose usage.
The More You Think, The More You Burn?
By now, you might be thinking of an interesting “strategy” to achieve your weight goal, like “think a lot to get a slim body.” However, unfortunately, it isn’t that simple.
In reality, the overall change in glucose consumption in the body is calculated in minutes. Solving equations might increase glucose expenditure in the brain by no more than 20 calories out of the total 300 calories (basal energy requirement). Therefore, this calorie increase is negligible compared to the overall energy expenditure of the brain.
Moreover, if cognitive tasks were to burn a significant amount of calories, they would need to be performed continuously for many hours. You might burn some calories by solving problems all day long, but under normal conditions, that won’t happen because we all have our cognitive limits.
We need breaks when our minds begin to feel “saturated” from a specific task. Additionally, many people might prefer to eat during these breaks. At this point, the calorie intake from food can exceed the calories we just burned, rendering the overall “calorie-burning” effect meaningless. Even if we manage to control our cravings, solving math problems can contribute very little to long-term weight loss or our periodic weight measurement.
Solving math problems all day might burn less than 20 calories, but walking for 30 minutes can help you burn up to 150 calories. Physical activities can burn more calories. Therefore, seek out high-intensity exercises to effectively burn calories in your body and achieve the balanced physique you desire.
