📝 Detailed Answer
In my younger days, I also tried fasting blindly to lose weight quickly, and I remember feeling so dizzy that it was impossible to function in daily life. Through that experience, I realized that the body perceives a sudden lack of nutrition as a state of emergency.
While Western medicine describes this mechanism as inducing fat burning by lowering insulin levels, from a Traditional Korean Medicine (TKM) perspective, this is closer to the 'depletion of Qi and Blood.' Specifically, it often leads to 'Spleen Deficiency' (Bi-heo, 脾虛), a state where the energy of the Spleen—the organ responsible for digestion and absorption—is weakened.
When weight is lost too aggressively in this state, it is easy for 'Phlegm-fluid' (Dam-eum, 痰飮), which are sticky metabolic waste products, and 'Blood Stasis' (Eo-hyeol, 瘀血), which is stagnant blood flow, to accumulate. When these accumulate, your body feels incredibly heavy, and edema (swelling) becomes harder to resolve.
The key is whether the weight loss occurs at a pace your body can handle. Simply eating less is not the answer. To achieve healthy weight loss without the 'yo-yo effect,' you must first boost your metabolic capacity and clear out internal waste. I recommend first assessing the current level of your body's vital energy.