The methods of calculating basal metabolic rate are divided into direct calorimetry, indirect calorimetry and formula calculation. 1. Direct calorimetry: Direct calorimetry is to place the subject in a special testing environment, collect the total amount of heat dissipated by the subject within a certain period of time, and then convert it into the metabolic amount per square meter of body surface per unit of time, i.e. the basal metabolic rate. This method is more accurate, due to the expensive and complicated operation, mainly used for scientific research. 2. Indirect calorimetry: According to the law of conservation of energy and matter, the three major energy producing nutrients in the energy consumption of oxygen and carbon dioxide produced by the existence of a fixed ratio relationship, using this relationship to calculate the basal metabolic rate, more accurate, but the price is also very expensive, mainly for scientific research. 3. Formula calculation method: This method is simple and can be widely used in clinical, preventive and sports medicine, but it is only an approximate value with errors and is for reference only. Basal metabolic rate % = (pulse rate + pulse pressure difference) – 111. Basal metabolic rate is mainly affected by thyroid hormones. If your basal metabolism is abnormal, please consult your doctor to find out the cause of the abnormality and cooperate with your doctor for treatment if necessary.