What is the formula for RQ?

What is the formula for RQ?

• A. CO2 produced / O2 consumed
• B. O2 consumed / CO2 produced
• C. CO2 produced × O2 consumed
• D. CO2 produced − O2 consumed

Answer: (A)

Respiratory quotient reflects what the body is oxidizing by comparing the amount of carbon dioxide produced to the amount of oxygen consumed. It is defined as the ratio VCO2 divided by VO2. This division captures the balance of fuel use: carbohydrate oxidation tends toward 1.0, fat oxidation toward about 0.7, and protein around 0.8–0.85. The key idea is that you’re forming a ratio from CO2 output and O2 uptake, not multiplying or subtracting them, and not reversing the order. In practice, this ratio is obtained from indirect calorimetry and helps indicate substrate utilization during metabolism. (Note: RER can differ from RQ in some clinical situations due to non-metabolic CO2 sources, but the formula remains CO2 produced divided by O2 consumed.)

Respiratory quotient reflects what the body is oxidizing by comparing the amount of carbon dioxide produced to the amount of oxygen consumed. It is defined as the ratio VCO2 divided by VO2. This division captures the balance of fuel use: carbohydrate oxidation tends toward 1.0, fat oxidation toward about 0.7, and protein around 0.8–0.85. The key idea is that you’re forming a ratio from CO2 output and O2 uptake, not multiplying or subtracting them, and not reversing the order. In practice, this ratio is obtained from indirect calorimetry and helps indicate substrate utilization during metabolism. (Note: RER can differ from RQ in some clinical situations due to non-metabolic CO2 sources, but the formula remains CO2 produced divided by O2 consumed.)