Basal metabolic rate formula for women

Basal metabolic rate (BMR) refers to the oxidative phosphorylation rate when the body is awake and extremely quiet, and is not affected by muscle activity, working temperature, food, stress, etc. [1]. That is, during basic physiological activities (i.e. blood circulation, breathing and stable body temperature), the minimum heat load per unit area per hour minus the standard heat load, and the error as a percentage of the standard heat load is called basal metabolism.

To measure basal metabolic rate, you need to rest for 30 minutes in the morning before breakfast (but keep your mind clear), maintain the room temperature at around 20°C, and use indirect calorimetry to measure. The basal metabolic rate is kJ/(m2/h) (kilojoules/square meter/hour), which is the kilojoules of heat released by each square meter of skin per hour.

Introduction to basal metabolism

Basal metabolism, to put it simply, the metabolism per unit time is called basal metabolism, which refers to the oxidative phosphorylation of the body under basic conditions, and the basic state refers to the state when a person is awake and very quiet, and is not affected by factors such as muscle activity, working temperature, food, and stress. . Anything less than or equal to 15% of the standard value is considered normal. The measurement of basal metabolism is a key auxiliary method for diagnosing thyroid disease. When the thyroid cyst function is more hyperactive, the basal metabolism can increase significantly, and when the thyroid cyst function is not high, the basal metabolism can decrease significantly.

In the clinical and physiological experiments, the subjects were required to have not eaten for at least 12 hours, and their metabolic rate was measured under the conditions of resting for 30 minutes at a room temperature of 20°C, keeping their mind clear and not engaging in any mental or physical activities.

Basic principles of accurate measurement of basal metabolism

According to the law of conservation of kinetic energy, the kinetic energy consumed by the body should be equal to the sum of the energy generated and the external work done. If the body does not do external work for a certain period of time, then the kinetic energy consumed is equivalent to the energy created per unit time. Because human body temperature is stable, the heat produced per unit time should be equivalent to the total heat released to the outside. Therefore, by measuring the total heat released by the body in a certain period of time, the body's oxidative phosphorylation rate can be understood.

Basal metabolic measurement

Based on the above precise measurement principles and continuous scientific research and testing, scholars from all over the world have summarized three methods for measuring BMR: direct calorimetry, indirect calorimetry and formula calculation method. The first two methods are the "gold standard" for measuring calorie consumption, while the formula calculation method is simpler and more convenient than the first two methods and is suitable for estimating BMR of large sample groups [3].

Basal metabolic immediate calorimetry

Direct calorimetry is to place the subject in a special test environment, collect the total heat emitted by the subject in a certain period of time (through radiation, transmission, convection and volatilization), and then calculate it into the metabolic rate per unit time, that is, the oxidative phosphorylation rate (energy metabolic rate). However, the equipment for direct calorimetry is relatively complicated and is mainly used to study obesity and endocrine disorders. The latter two methods are mainly used for accurate measurement of general population.