By Mukaila Kareem
We have been taught to think about body weight like an arithmetic problem. The “calories in, calories out” mantra is a mental concept that portrays the body as a container. Add here, subtract there, and if the numbers balance, everything stays the same. We are often told that sugar behaves like money in a checking account, while fat is like a long-term deposit for storage. This analogy sounds neat and logical, but the human body is not a bank account. It is also not a sealed container where energy simply piles up or drains away. The human body is a living system built on movement, and movement is about flow, not arithmetic.
Even at rest, the body is not idle. Energy is constantly being used. The heart pumps and the lungs move air. The skin may appear passive, but it is constantly renewing itself and quietly exchanging heat and waste with the outside world without our awareness. In a living system, old cells break down while new ones are built. Heat is generated and released, facilitating the continuous progression of life with each passing second. In essence, metabolism does not pause and restart like a machine in a repair shop. If it stops, life stops. We are therefore never static and even in sleep, energy remains in motion.
When one stands up and walks, the pace of energy flow rises. Blood moves faster and heat increases. The whole body shifts into higher gear. Therefore, the difference between sitting and walking is not just a few extra calories burned. It is a change in energy flow or a rise in metabolic power. Like a river already in motion, the flow begins to move faster.
This is where simple calorie arithmetic falls short. It treats the so-called “calories out” like a fixed drain at the bottom of a water tank. In real life, that drain widens or narrows depending on whether life is active or sedentary. A body that moves often runs like a fast stream. A body that rarely moves becomes more like a slow pond. That is why the same amount of food can behave differently in different people. Because life is continuous, when things slow down, they do not break immediately. However, energy flow slows, waste lingers longer, and heat release narrows. Over time, that lingering can matter. Not because physics is broken, but because flow has changed.
All over the world, traditional farming communities, whether in tropical villages or temperate fields, do not count calories. They match food with daily movement without spreadsheets or scales. Their bodies are in constant motion due to walking, lifting, bending and carrying. Therefore, energy flow is built into life, and arithmetic calorie counting becomes less central.None of these denies that energy balance exists, but balance is dynamic. It depends on how wide the river is, not just how much water enters it. When public health focuses only on the subtraction mantra of “eat less, burn more,” it misses the deeper point. The body thrives when energy moves smoothly through it. Metabolism abhors stagnation. Life is not a still pond. It is a current in motion. Therefore, the question is not only how much you eat, but whether your daily life keeps the river flowing.
Mukaila Kareem, a doctor of physiotherapy and physical therapy advocate, writes from the USA and can be reached via makkareem5@gmail.com
