Resting Metabolic Rate (RMR)
Energy expended at rest in a thermoneutral environment to maintain basic physiological functions, accounting for 60-75% of total daily energy expenditure in sedentary adults.
Also: BMR, Basal metabolic rate, RMR
BMR is measured under stringent conditions (overnight fast, supine, immediately upon waking); RMR is the more practical measurement, typically 3-5% higher. Determined primarily by fat-free mass, RMR is reduced by aging (~2% per decade), undernutrition, and weight loss (the basis of adaptive thermogenesis). Indirect calorimetry is the clinical reference; predictive equations (Harris-Benedict, Mifflin-St Jeor) are commonly used clinical approximations.
How one textbook covers it
Modern Nutrition in Health and Disease, 12th ed. — Ch 1: Energy
BMR is measured under stringent conditions (overnight fast, supine, immediately upon waking); RMR is the more practical measurement, typically 3-5% higher. Determined primarily by fat-free mass, RMR is reduced by aging (~2% per decade), undernutrition, and weight loss (the basis of adaptive thermogenesis). Indirect calorimetry is the clinical reference; predictive equations (Harris-Benedict, Mifflin-St Jeor) are commonly used clinical approximations.
Related terms
Doubly labeled water, Thermogenesis, Total energy expenditure