The reference protein is?

NCL (MP) Nursing Officer - 2019

Applied Nutrition & Dietetics

Easy

Appeared in: NCL (MP) Nursing Officer - 2019

Explanation

Egg protein is designated as the 'reference protein' because it contains all nine essential amino acids in the most optimal proportions for human requirements.
It has the highest Biological Value (BV) among natural food sources, typically cited as 100 (or 94), meaning the body can use it very efficiently for tissue synthesis and repair.
Due to its near-perfect amino acid profile and high digestibility, nutritionists use egg protein as the standard to measure the quality of other dietary proteins.
The Net Protein Utilization (NPU) of egg is also the highest, at approximately 100, indicating that almost all of the ingested egg protein is retained and utilized by the body.

Option B: Milk contains high-quality complete proteins (casein and whey) but has a slightly lower Biological Value (around 91) compared to egg protein. Therefore, it is not the reference standard.
Option C: Meat is a source of complete protein and is rich in other nutrients like iron and vitamin B12. However, its Biological Value (around 80) is lower than that of egg, so it is not the reference protein.
Option D: Fish provides complete protein with a good amino acid balance and beneficial omega-3 fatty acids. Its Biological Value (around 78) is high but still lower than egg's, disqualifying it as the reference standard.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Reference Protein and Protein Quality Assessment as background academic context rather than a clinical decision trigger.
Nurses advise patients with increased metabolic needs (e.g., post-surgery, burn victims, sepsis) to consume high-BV proteins like eggs to promote efficient tissue repair and recovery.
In cases of protein-energy malnutrition, especially in children, recommending affordable and high-quality protein sources like eggs is a key nutritional intervention to support growth and development.
Patient education often involves explaining the concept of 'complete' vs. 'incomplete' proteins. Using egg as an example of a perfect complete protein helps clarify this concept.

How to Approach the Question

First, identify the key term in the question: 'reference protein'.
Recall the definition of a 'reference protein' in nutrition. It is the food protein with the highest biological value, used as a standard to compare other proteins.
Evaluate the given options (Egg, Milk, Meat, Fish) based on your knowledge of protein quality.
Remember that while all options are high-quality proteins, egg protein is universally cited in nutrition science as the benchmark or reference standard due to its 'perfect' amino acid profile for human needs.
Select 'Egg' as the correct answer because it fits the definition of a reference protein with a Biological Value of 100.

Concept Tested & Keywords

QDt7EI05SmsGPCHiXmvgU6

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) pp. 165-167, 144-146