I have personally experienced the pitfalls of extreme fasting out of sheer willpower, and I remember the dizziness and lack of focus that seriously hindered my work. Having gone through that 'trial and error,' I fully empathize with the desire for quick results. Medically, rapid weight loss is a process of forcibly switching the body's energy source. When carbohydrate supply is cut off, the body first utilizes glycogen stored in the liver and muscles, then begins burning fat. However, because significant amounts of water are lost during this process, the initial drop in scale weight is often deceptive. In Traditional Korean Medicine (TKM), we don't view weight loss as simply a result of 'eating less.' A sudden reduction in food intake often leads to 'Bi-heo' (脾虛), or Spleen Deficiency. As digestive and absorptive functions weaken, you feel lethargic and metabolic efficiency drops, creating an environment where 'Dam-eum' (痰飮)—the accumulation of metabolic waste and phlegm—easily builds up. Weight lost while the metabolism is compromised is highly likely to lead to the yo-yo effect, as residues remain in the body similar to 'Eo-hyeol' (瘀血, blood stasis). Therefore, rather than blindly restricting calories, it is far more important to first 'flip the metabolic switch' of your body. Let's discuss whether your current physical condition can safely withstand a short-term weight loss regimen.