During starvation, the non-protein RQ value is close to

**Core Concept**
The non-protein respiratory quotient (RQ) is a measure of the ratio of carbon dioxide production to oxygen consumption, primarily reflecting the metabolic fate of carbohydrates, fats, and proteins. During starvation, the body undergoes metabolic adaptations to utilize stored fat as a primary energy source.

**Why the Correct Answer is Right**
During starvation, the body relies heavily on fat breakdown (lipolysis) to provide energy. When fat is broken down, it produces ketone bodies (acetoacetate, beta-hydroxybutyrate, and acetone) as intermediate products. The complete oxidation of one mole of acetoacetate produces 3 moles of CO2 and 4 moles of O2. This leads to an RQ value of approximately 0.7, reflecting the predominantly fat-based metabolism during starvation.

**Why Each Wrong Option is Incorrect**
* **Option A:** This value is incorrect because it does not accurately reflect the RQ during starvation. Typically, the RQ for carbohydrates is around 1, proteins around 0.8, and fats around 0.7.
* **Option B:** This value is incorrect because it is not relevant to starvation metabolism. During fasting, the body's reliance on fat metabolism significantly shifts the RQ away from this value.
* **Option C:** This value is incorrect because it is too high for fat-based metabolism. While the RQ for carbohydrates is close to 1, the RQ for fats is significantly lower.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that during prolonged fasting or starvation, the body's reliance on fat metabolism can lead to ketosis, a metabolic state characterized by elevated levels of ketone bodies in the blood.

**Correct Answer: C. 0.7**