Combining legumes and grains successfully addresses individual amino acid deficiencies—such as the lack of methionine in legumes—thereby achieving a complete protein profile through mutual complementation.
The retrieved literature consistently supports the long-standing nutritional principle that combining plant proteins like legumes and grains compensates for individual amino acid limitations (such as sulfur-containing amino acids in legumes) to achieve a complete protein profile. Multiple papers explicitly discuss the necessity and effectiveness of plant protein complementation.