NPU of egg is

**Core Concept**
The Net Protein Utilization (NPU) of a food is a measure of its ability to provide amino acids for protein synthesis, calculated as the ratio of amino acid converted to proteins to the amino acid supplied. Egg is a high-quality protein source, rich in essential amino acids.

**Why the Correct Answer is Right**
Egg has an NPU of approximately 96, indicating that nearly all its protein content is utilized for protein synthesis. This is due to its high concentration of essential amino acids, particularly methionine and tryptophan, which are crucial for protein synthesis and growth. The NPU of egg is higher than most plant-based protein sources, making it an excellent choice for individuals requiring high protein intake.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the NPU of egg is not around 50, which would indicate low protein quality and efficiency.
**Option B:** Incorrect because the NPU of egg is not around 70, which would suggest moderate protein quality and efficiency.
**Option C:** Incorrect because the NPU of egg is not around 80, which would indicate good protein quality and efficiency, but not as high as egg.

**Clinical Pearl / High-Yield Fact**
When counseling patients on high-protein diets, it's essential to emphasize the importance of choosing high-quality protein sources like eggs, which have a high NPU and provide essential amino acids for optimal protein synthesis.

**Correct Answer:** C. 80