The living tissues of the human body consume energy during various activities, or with performing their biological function, however even when resting our bodies consume energy to sustain life. Some organs of the body function non-stop even during sleep, like the heart and lungs. The amount of energy consumed at rest is known as the Resting Metabolic Rate, and it varies with one’s age, gender, body size and its composition. At absolute rest, in laboratory conditions, this parameter is known as the Basal Metabolic Rate.
Resting Metabolic Rate is an essential component of the Metabolism, the process of energy exchange with the environment, made up of energy intake (anabolism) and energy expenditure (catabolism). The Energy Balance Equation compares the energy intake with the energy expenditure. and gives indication on the body’s weight control. The measured RMR classifies individuals into fast, normal or slow metabolisers, with implications on weight control.
We measure the RMR using calorimetry of the ventilated air at rest. The subject lies down in a relaxed position and maintains stillness for a certain amount of time having a mask over the nose and mouth to capture ventilated air which is than sampled for RMR by a medical grade calorimeter. The test takes approx 15min and it does not require any effort or exertion other than breathing. It is recommended to have this test done either on an empty stomach or few hours after a meal. This test is applicable to adolescents and adults. It does not require undressing, only light clothing taking place at room temperature.