The subject of the invention is the use of a protein material whose rate of digestion has been reduced, for the preparation of an enteral composition which makes it possible to modulate the postprandial plasma amino acid level, said protein material having been previously treated so as to convert the fast-digesting proteins which it contains to slow-digesting proteins, characterized in that the slow-digesting protein material is a material containing microparticulate gelled proteins combined with polysaccharides under conditions of thermodynamic incompatibility.