Individual food efficiencyA few examples of amino acid efficiencies: Apricots have a low amino acid efficiency, because of their low methionine content. Wheat products such as bread have a medium amino acid efficiency, limited by their lysine content. Quinoa has a high amino acid efficiency.
A sandwich combining bread and cheese (camembert) in equal proportions is almost twice as efficient as any of its components taken alone.
On the other hand, bread and peanut butter may taste very good, but exhibit no synergy as far as amino acids are concerned: combining the two does not allow higher efficiencies to be achieved than those of the individual components.