Biological Value and the Chicken Egg
The Gold Standard of Proteins.
Anyone dealing with proteins inevitably comes across biological value. In nutrition, quality is not an abstract concept – it is a measurable performance.

The ultimate measure.
The chicken egg is often referred to as the ultimate. The reason for this is its biological value (BV). This indicates how efficiently a dietary protein can be converted into the body's own protein (e.g., muscles).
The formula is simple: the more similar the amino acid profile of a food is to that of the human body, the less your organism has to "rebuild." The whole egg used to be considered the highest quality source, which is why the reference value of 100 was arbitrarily assigned to it.
Reference 100
The chicken egg is not a percentage, but the fixed point against which all others are measured.
Synergy Effects
Clever combinations cover mutual weaknesses and exceed the value of 100.
Plant Power
Often below 100 in isolation, plant sources achieve absolute peak values in combination.

Combination as the key.
No single food is perfectly complete. The amino acid profile is often limited by a so-called "limiting amino acid." By strategically mixing different sources, these building blocks complement each other.
Ultimately, a high biological value means that you need to consume less protein overall to meet your needs for muscle growth and regeneration. Quality demonstrably trumps quantity here.