How is resting metabolic rate typically measured?

Resting metabolic rate (RMR) is typically measured using calorimetry, which involves assessing the amount of heat produced by the body, reflecting energy expenditure. There are two main types of calorimetry: direct and indirect. Direct calorimetry measures the heat produced by the body in a controlled environment, while indirect calorimetry estimates RMR by measuring the oxygen consumed and carbon dioxide produced during respiration. This method provides a quantitative assessment of energy expenditure while at rest, which is essential for determining an individual's metabolic needs.

Other methods, such as dietary logs or food questionnaires, focus on food intake rather than measuring metabolic processes directly. They can provide insights into dietary habits but do not measure metabolic rate. Physical activity assessments also do not measure RMR, as they evaluate energy expenditure related to physical activity rather than resting conditions. Therefore, calorimetry stands out as the primary method for accurately measuring resting metabolic rate.