In the past, many people attempted rigid diets consisting only of chicken breast and sweet potatoes, only to experience dizziness and exhaustion. This happens because the body is highly adaptive; when caloric intake drops significantly, the body automatically lowers its metabolic rate to survive, resulting in the common 'weight-loss plateau.' From a Western medical perspective, when levels of leptin—the hormone that regulates appetite—drop, the brain perceives a state of crisis. The original purpose of a cheating day is to send a signal to the brain that 'food is plentiful,' thereby restarting the metabolic process. In Traditional Korean Medicine (TKM), this state of metabolic slowdown is often viewed as 'Bi-heo' (脾虛), or Spleen Deficiency. When the function of the Spleen is weakened, the body cannot efficiently transform nutrients into energy. The resulting metabolic waste accumulates as 'Dam-eum' (痰飮, phlegm-fluid), which obstructs circulation and further lowers metabolism. If this is compounded by 'Eo-hyeol' (瘀血, blood stasis), the body may shift into a constitution where weight loss is difficult regardless of calorie restriction. Therefore, a cheating day should not be viewed simply as a 'day to eat whatever I want,' but as a process to reactivate the metabolic switch. It is important to note that individuals with a severely weak Spleen and Stomach may experience digestive distress or sudden edema (swelling) if they consume high-fat or high-sugar foods abruptly. I recommend tailoring the intensity of your cheating day to your current physical condition and planning it in consultation with a practitioner.