Plasma amino acid response to ingestion of L-amino acids and whole protein.

The effect of whole protein and L-amino acid ingestion on plasma amino acid concentrations was investigated in 10 men. Each subject ingested equivalent amounts of amino acids as cottage cheese (session 1), an L-amino acid mixture (session 2), and cottage cheese and L-amino acids (session 3). Postprandial changes from baseline were larger for essential versus nonessential amino acids in each session. Higher and more rapid rises followed by more rapid declines in individual plasma amino acid concentrations were observed after ingestion of L-amino acids alone or with whole protein than after ingestion of an equivalent amount of amino acids as whole protein. Individuals receiving the majority of their essential amino acid and nitrogen needs from elemental products may need, for example, to consume them more frequently or after consumption of other foods in an effort to slow down absorption rates.