Why do I experience heart palpitations and insomnia when taking diet supplements? I'm wondering if these are side effects.

I understand how frustrating it is to struggle with sleepless nights and restlessness when you are simply trying to improve your health. Many commercial supplements act like a 'whip,' forcing the body to expend energy it doesn't have. From a Western medical perspective, they temporarily increase the basal metabolic rate by stimulating the sympathetic nervous system. However, the human body is not a machine; constant stimulation overloads the nervous system, resulting in the heart palpitations and insomnia you are experiencing. In Traditional Korean Medicine (TKM), this state is viewed as a deficiency of vital energy (Qi), often related to Spleen Deficiency (Bi-heo, 脾虛). When the Spleen's function is weakened, nutrient absorption and energy metabolism are compromised. Forcing the metabolism to rise under these conditions inevitably disrupts the body's internal balance. Furthermore, if the body contains 'Dam-eum' (phlegm-fluid retention) or 'Eo-hyeol' (blood stasis)—stagnant waste and poor circulation—the stimulants in these supplements can act as toxins rather than aids, further deteriorating your overall condition. Ultimately, restoring the body's 'foundational strength' is more critical than the act of losing weight itself. Rather than fasting or using stimulants, it is far more important to normalize your metabolism within a range your body can handle. I would like to help you determine whether these symptoms are a simple adjustment period or a critical warning signal from your body.