have read in many places that a serving
of rice and beans provides complete protein
- more complete than a serving of beef.
Recently a woman disputed this and I thought
it might be a good idea to check it out
before I tell anyone again.
Quality (complete) Proteins are dietary
proteins that contain sufficient quantities
of all essential amino acids (present in
animal foods only - the only plant food
that is a complete protein is soy).
Quality (incomplete) Proteins are Dietary
proteins that are low or lack one or more
essential amino acids (usually in plant
foods eg wheat and rice lacks lysine, corn
lacks lysine and tryptophan, legumes (except
soy) and nuts lack methionine.
incomplete proteins are combined in the
same meal e.g cereals are eaten with egumes,
they become complete proteins, equivalent
to protein quality of meat (but not better
evidence suggests that there is no need
to combine incomplete proteins at every
meal - as long as one consumes a variety
of protein containing foods across the day.
position paper by the American
Dietetic Association has more information
on the evidence.
Updated: October 30, 2001.