The protein quality indicator adopted by ICMR in recommending dietary protein requirements is
**Core Concept**
The protein quality indicator adopted by ICMR in recommending dietary protein requirements is a measure of the amino acid composition of a protein source, assessing its ability to support human health. This concept is crucial in evaluating the nutritional value of various protein sources, such as plant-based proteins, animal-derived proteins, and protein supplements.
**Why the Correct Answer is Right**
The correct answer is **Nitrogen Balance (NB)**. Nitrogen balance is a measure of the difference between the amount of nitrogen ingested and the amount of nitrogen excreted. A positive nitrogen balance indicates that the body is in a state of protein synthesis, where the amount of nitrogen ingested exceeds the amount excreted. This is essential for growth, maintenance, and repair of body tissues. ICMR recommends dietary protein requirements based on nitrogen balance, taking into account factors such as age, sex, weight, and activity level.
**Why Each Wrong Option is Incorrect**
* **Option A:** **Biological Value (BV)** is a measure of the proportion of absorbed protein that is retained by the body, but it does not account for the overall quality of the protein source.
* **Option B:** **Net Protein Utilization (NPU)** is a measure of the efficiency with which the body uses dietary protein, but it is not directly related to the protein quality indicator adopted by ICMR.
* **Option C:** **Protein Efficiency Ratio (PER)** is a measure of the rate at which a protein source promotes growth in experimental animals, but it is not a practical or relevant indicator for human dietary protein requirements.
**Clinical Pearl / High-Yield Fact**
A positive nitrogen balance is essential for growth, maintenance, and repair of body tissues, particularly during periods of rapid growth, such as childhood and adolescence, or during recovery from illness or injury.
**Correct Answer: D. Nitrogen Balance**