From a Western medical perspective, the mechanism is clear: the simple sugars in commercial sauces cause rapid blood sugar spikes. This triggers excessive insulin secretion, leading to a state of insulin resistance where excess sugar is stored as body fat. Even if the total calories remain similar, a high-sugar sauce can shift your body into a 'fat-storage' constitution. In Traditional Korean Medicine (TKM), we approach this through the concept of 'Spleen Deficiency' (Biheo, 脾虛). The Spleen is responsible for the transformation and transportation of nutrients. Stimulating and overly sweet sauces place a heavy burden on the Spleen, preventing nutrients from being converted into energy. Instead, they turn into 'Phlegm-fluid' (Dameum, 痰飮), which is non-physiological metabolic waste that accumulates in the body. Furthermore, the high sodium content in these sauces contributes to 'Blood Stasis' (Eohyeol, 瘀血), where blood circulation becomes stagnant. This leads to edema (swelling), creating a vicious cycle where fluid retention eventually hardens into stubborn body fat. Sauce is not just a condiment for flavor; it is a metabolic switch that can flip your system from 'burning' to 'storing.' This is why choosing your sauce is just as critical as selecting your vegetables.