Legume - Nutritional Facts

Nutritional Facts

Legumes contain relatively low quantities of the essential amino acid methionine, as compared to whole eggs, dairy products or meat. This means that a smaller proportion of the plant proteins, compared to proteins from eggs or meat, may be used for the synthesis of protein in humans. The portion of plant proteins not suitable for the synthesis of human proteins is instead used as fuel in the human metabolism.

Nevertheless, legumes are among the best protein sources in the plant kingdom. The low concentrations of the amino acid methionine in legumes may be compensated for simply by eating more of them. Since legumes are relatively cheap compared to meat, eating more legumes may be an alternative to meat for some.

According to the protein combining theory, legumes should be combined with another protein source such as a grain in the same meal, to balance out the amino acid levels. Protein combining has lost favor as theory (with even its original proponent, Frances Moore Lappé, rejecting the need for protein combining in 1981). A variety of protein sources is considered healthy, but they do not have to be consumed at the same meal. In any case, vegetarian cultures often serve legumes along with grains, which are low in the essential amino acid lysine, creating a more complete protein than either the beans or the grains on their own.

Common examples of such combinations are dal with rice by Indians, beans with corn tortillas, tofu with rice, and peanut butter with wheat bread.