Rebound weight gain is not simply about regaining fat but indicates a collapse of the body's regulatory ability. In Traditional Korean Medicine, the main causes are spleen deficiency (脾虛, biheo) and phlegm-fluid accumulation (痰飮, dameum). A weak spleen impairs metabolism, and residues accumulate as phlegm-fluid, making weight loss difficult and promoting a constitution prone to regain. Based on Sasang constitution (四象體質, sasang chejil) and individual tendencies (e.g., phlegm, blood stasis, qi stagnation), a five-step approach is used: 1) Constitution assessment—e.g., Shaoyin type has weak digestion, so high-protein low-carb diets may worsen spleen deficiency. 2) Custom diet—e.g., Taiyin benefits from bitter vegetables that support liver, while Shaoyang benefits from seaweed to protect kidneys. 3) Herbal prescriptions—Buzhong Yiqi Tang (補中益氣湯) to strengthen spleen qi or Erchen Tang (二陳湯) variations to eliminate phlegm-fluid. These support organ function rather than simply 'reducing' weight. 4) Movement reset—Instead of intense cardio, adjust exercise intensity and duration per constitution; those with severe spleen deficiency should start with walking or gentle stretching. 5) Stress and sleep management—Liver qi stagnation (肝氣鬱結, gan gi ulgyeol) disrupts appetite hormones, and poor sleep weakens spleen function. Acupuncture or herbs harmonize qi flow, allowing the body to self-regulate. This process is gradual over 1–2 month cycles, focusing on adapting to one's constitution rather than forcing change.