Basal metabolic rate, and the closely related resting metabolic rate (RMR), is the amount of daily energy expended while at rest in a neutrally temperate environment, in the post-absorptive state (meaning that the digestive system is inactive, which requires about twelve hours of fasting in humans).
- direct calorimetry
measurement of heat actually produced by the organism which is confined in a sealed chamber or calorimeter.
- indirect calorimetry
estimation of the heat produced by means of the respiratory differences of oxygen and carbon dioxide in the inspired and expired air.
Resting metabolic rate (RMR) or Resting energy expenditure (REE) is whole-body mammal (and other vertebrate) metabolism during a time period of strict and steady resting conditions that are defined by a combination of assumptions of physiological homeostasis and biological equilibrium. RMR differs from basal metabolic rate (BMR) because BMR measurements must meet total physiological equilibrium whereas RMR conditions of measurement can be altered and defined by the contextual limitations. Therefore, BMR is measured in the elusive "perfect" steady state, whereas RMR measurement is more accessible and thus, represents most, if not all measurements or estimates of daily energy expenditure.
Resting energy expenditure thyroid
UCP2 and Vitamin D