The respiratory quotient (RQ) value associated with substrate utilization patterns in normal, healthy individuals is which value?

The respiratory quotient (RQ) value associated with substrate utilization patterns in normal, healthy individuals is which value?

• A. 0.6
• B. 0.8
• C. 0.7
• D. 1.0

Answer: (B)

The main idea is that the respiratory quotient (RQ) tells you what fuel the body is mainly burning based on the CO2 produced per O2 consumed during metabolism. Different fuels give characteristic RQ values: carbohydrates yield about 1.0, fats about 0.7, and proteins around 0.8. In a normal, healthy person at rest with a mixed diet, the body uses a combination of these fuels, which typically results in an RQ near 0.8. So the value associated with normal substrate utilization patterns is around 0.8, reflecting a balanced mix of fat and protein (with some carbohydrate) oxidation. Values closer to 1.0 indicate predominant carbohydrate use, while values around 0.7 indicate fat-dominated metabolism.

The main idea is that the respiratory quotient (RQ) tells you what fuel the body is mainly burning based on the CO2 produced per O2 consumed during metabolism. Different fuels give characteristic RQ values: carbohydrates yield about 1.0, fats about 0.7, and proteins around 0.8. In a normal, healthy person at rest with a mixed diet, the body uses a combination of these fuels, which typically results in an RQ near 0.8. So the value associated with normal substrate utilization patterns is around 0.8, reflecting a balanced mix of fat and protein (with some carbohydrate) oxidation. Values closer to 1.0 indicate predominant carbohydrate use, while values around 0.7 indicate fat-dominated metabolism.