Answer:
The correct answer is- Indirect calorimetry
Step-by-step explanation:
Indirect calorimetry is the method which is used to estimate the energy expenditure by measuring the amount of consumed oxygen and the amount of carbon dioxide produced.
For estimating energy expenditure we should know that energy production means the conversion of chemical-free energy present in foods into ATP form with the addition of some energy loss in the oxidation process.
This method is a highly accurate method of metabolic rate and is the gold standard method for critically ill patients. So the right answer is indirect calorimetry.