Q. What exactly is body fat percentage, and why is it the key factor in determining the success of a diet?

I have personally experienced the struggle of being 'skinny fat' during busy clinical periods due to skipped meals and late-night snacking. Despite having a normal weight, my high body fat percentage left me feeling chronically fatigued. From a Western medical perspective, an increase in visceral fat leads to insulin resistance, a state where the body stops using carbohydrates as fuel and instead funnels them into fat storage. In Traditional Korean Medicine (TKM), we interpret this process through the relationship between Spleen Deficiency (Bi-heo) and Phlegm-fluid (Dameum). The Spleen is responsible for the 'Transportation and Transformation (Un-hwa)' function—essentially the engine that circulates energy. When this engine weakens, the body fails to fully process nutrients, leaving behind sticky waste known as Phlegm-fluid. As Phlegm-fluid accumulates and obstructs the circulation of Qi and Blood, metabolism slows further, creating a 'low-efficiency body.' Therefore, lowering your body fat percentage is not about starving to change a number on the scale. It is about restoring the Spleen's functional health to discharge Phlegm-fluid and restart the body's energy factory. The core of a TKM diet is to transform stagnant body fat back into flowing, usable energy.