In RER values, which value indicates fat oxidation predominates?

In RER values, which value indicates fat oxidation predominates?

• A. 1.0
• B. 0.7
• C. 0.85
• D. Greater than 1

Answer: (B)

RER shows which fuel is being burned by comparing CO2 produced to O2 consumed. Fat oxidation uses more O2 per CO2 produced, so the ratio sits toward the lower end of the scale when fat is the main fuel. Carbohydrate oxidation produces more CO2 for the same amount of O2, pushing the ratio toward the higher end. A value in the middle suggests a mix of fats and carbohydrates; a value above 1 typically indicates some anaerobic processes or buffering of lactic acid that raises CO2. Therefore, the value indicating fat oxidation predominates is the one toward the left end of the scale.

RER shows which fuel is being burned by comparing CO2 produced to O2 consumed. Fat oxidation uses more O2 per CO2 produced, so the ratio sits toward the lower end of the scale when fat is the main fuel. Carbohydrate oxidation produces more CO2 for the same amount of O2, pushing the ratio toward the higher end. A value in the middle suggests a mix of fats and carbohydrates; a value above 1 typically indicates some anaerobic processes or buffering of lactic acid that raises CO2. Therefore, the value indicating fat oxidation predominates is the one toward the left end of the scale.