Nigeria, March 2 -- 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 l...