What is the normal respiratory quotient?

What is the normal respiratory quotient?

• A. 0.8
• B. 1.0
• C. 0.6
• D. 0.9

Answer: (A)

The respiratory quotient shows how much CO2 is produced relative to O2 consumed during metabolism, reflecting which fuels the body is burning. For a typical mixed diet, the ratio lands around 0.8 because carbohydrate oxidation tends toward 1.0, fat around 0.7, and protein near 0.8; with a mix of substrates, the overall value is about 0.8. So the normal respiration quotient is approximately 0.8. Values near 1.0 suggest mostly carbohydrate use, while lower values (near 0.7) point to predominant fat use.

The respiratory quotient shows how much CO2 is produced relative to O2 consumed during metabolism, reflecting which fuels the body is burning. For a typical mixed diet, the ratio lands around 0.8 because carbohydrate oxidation tends toward 1.0, fat around 0.7, and protein near 0.8; with a mix of substrates, the overall value is about 0.8. So the normal respiration quotient is approximately 0.8. Values near 1.0 suggest mostly carbohydrate use, while lower values (near 0.7) point to predominant fat use.