RQ = CO₂ Production / O₂ Consumption

English Name: Respiratory Quotient, RQ

Normal Range: Under physiological conditions, the respiratory quotient for mixed food intake is 0.85

The respiratory quotient refers to the molecular ratio of CO₂ released and O₂ absorbed during respiration. If the main energy source is carbohydrates, the respiratory quotient is close to 1.00; if the main energy source is fats, the respiratory quotient is close to 0.71. In cases of prolonged pathological starvation, where the main energy source is the body's own proteins and fats, the respiratory quotient is close to 0.80. Generally, when consuming mixed food, the respiratory quotient is around 0.85.