Basal metabolic rate (BMR)

The energy cost of maintaining the metabolic integrity of the body, nerve and muscle tone, respiration and circulation. For children it also includes the energy cost of growth. Experimentally, BMR is measured as the heat output from the body, or the rate of oxygen consumption, under strictly standardised conditions, 12-14 hours after the last meal, completely at rest (but not asleep) and at an environmental temperature of 26-30°C, to ensure thermal neutrality.

The energy requirements necessary for maintenance of life processes such as heart beat, breathing, and cell metabolic activities.

The level of energy required to sustain the body’s vital functions in the waking state, when the individual is in a fasted condition, at normal body and room temperature, and without psychological stress.

A measure of the energy necessary for maintaining basic functions, such as breathing, heart rate, and digestion.

The amount of energy expended for involuntary functions of the body per unit of time: measured under standard conditions, affecting age, sex, size, shape of the body, and physiological state, basal metabolism.

The amount of energy used by the body in exchanging oxygen and carbon dioxide when at rest. It was formerly used as a way of testing thyroid gland activity.

Energy required to keep up the involuntary work of the fully-relaxed body, such as respiration, circulation and maintenance of body temperature.

The minimal amount of energy needed to sustain the body’s metabolism. Frequently expressed in terms of the amount of oxygen used to sustain this metabolism because of the constancy between energy flux and oxygen use.

The level of energy expended at rest following an overnight fast is considered the basal metabolic rate (BMR). Thus, BMR describes the lowest amount of energy that must be expended to support the body’s physiological processes. This differs from resting metabolic rate (RMR), also known as resting energy expenditure, only RMR is not always measured following an overnight fast prior to any of the days’ activities. Body weight accounts for approximately 75% of variation among individuals’ BMR, with the level lean body mass being the most important component.52 Vital organs, such as the brain, liver, heart, and kidneys expend much of the basal energy. Interestingly, active transport processes (the movement of particles across cellular membranes that requires energy) contribute significantly to BMR.

Physiological consumption of calories as measured 12 hours after eating, sleeping, and being at complete rest.

A measurement of thyroid function, via a breathing test that measures oxygen used and calories spent while the body is at rest.

The metabolic rate as measured 12 hr after eating, after a restful sleep, no exercise or activity preceding testing, elimination of emotional excitement, and in a comfortable temperature. It is usually expressed in terms of kilocalories per square meter of body surface per hour. It increases, for example, in hyperthyroidism.

The amount of energy (calories) expended by the body at rest to sustain vital functions.

The minimum amount of energy required to keep the body alive when in a rested and fasting state.

The rate at which a person uses energy when the body is at rest.

Amount of calories the body burns when at rest, but awake, over the course of one day.

Basal metabolic rate refers to the rate at which the body utilizes energy to sustain essential functions necessary for life. These vital functions encompass breathing, circulation, digestion, and other fundamental processes.

The lowest amount of body heat generated after 12 hours of fasting and while in a completely resting position.