Why should REE measured by indirect calorimetry be used as the caloric target without addition of stress or activity factors?

• A. REE measured under steady state conditions closely approximates true 24 hour energy expenditure.
• B. The addition of stress or activity factor is essential to account for illness.
• C. REE is always lower than total energy expenditure.
• D. REE is unaffected by fasting

Answer: (A)

Indicate the body's baseline energy needs by measuring resting energy expenditure (REE) under steady-state, fasting conditions. In a patient whose physiology is stable, this REE value closely mirrors the amount of energy the body would require over a 24-hour period to maintain essential functions. Because that measurement already reflects the current metabolic state, adding stress or activity multipliers would double-count factors that are already influencing the rate, risking overfeeding. Using REE as the caloric target provides a precise, state-specific starting point for nutrition support, with adjustments made only if the patient’s condition changes.