Rustmetabolische

Rustmetabolische, commonly referred to in English as resting metabolic rate (RMR), is the amount of energy the body uses while at rest to maintain essential physiological functions such as breathing, blood circulation, and cellular processes. It represents the baseline level of energy required for basic life-sustaining activities and often constitutes the largest portion of an individual’s total daily energy expenditure, especially for people with low levels of physical activity.

Measurement and estimation methods: RMR is typically measured in a thermally neutral environment after an overnight fast and a period of rest, using indirect calorimetry to assess oxygen consumption and carbon dioxide production. When direct measurement is not available, RMR can be estimated with predictive equations that use factors such as age, sex, height, and weight. These equations provide useful estimates but come with margins of error that vary by population.

Determinants and variability: Lean body mass is the strongest determinant of RMR, with higher muscle mass generally increasing energy needs. Other factors include age, sex, hormonal status, sleep quality, recent caffeine or nicotine intake, medications, and certain diseases. RMR can vary day to day and can be influenced by environmental temperature and recent physical activity.

Clinical and practical relevance: RMR informs dietary planning, weight management, and clinical nutrition. It helps set initial daily energy targets for weight loss, gain, or maintenance and can be adjusted based on monitoring outcomes and objectives. It is related to but distinct from basal metabolic rate (BMR), which is measured under stricter conditions and often yields slightly lower values.

See also: Basal metabolic rate, indirect calorimetry, energy expenditure, predictive equations.