On wikipedia this definition is given of a
complete protein:
a source of protein that contains an adequate proportion of all nine of the essential amino acids necessary for the dietary needs of humans or other animals. Some incomplete protein sources may contain all essential amino acids, but a complete protein contains them in correct proportions for supporting biological functions in the human body.
Apart from some exceptions such as quiona or soybeans, vegetable sources of protein are more often lower in one or more essential amino acids than animal sources, especially lysine, and to a lesser extent methionine and threonine.
From
Medline we can see that:
Sources of incomplete protein include beans, peas, nuts, seeds, and grain. A small amount of incomplete protein is also found in vegetables. Plant proteins can be combined to provide all of the essential amino acids and form a complete protein. Examples of combined, complete plant proteins are rice and beans, wheat cereal, and corn and beans.
Moreover I have looked up your foods on nutritiondata.com.
Here they are:
oat bran,
sweet potato,
bread, and
pasta.
If you look at the protein profile for your foods you can see
that they contain all amino acids, making your sources incomplete due
to insufficiency.
With all of this in mind, I believe that the answer to your question
for your particular case is yes. I say this because you mention
eating your oat meal with chicken -- a complete protein. I'm also
assuming you do this with the other foods you listed as well.
In general, the best answer is it depends. For the protein from all
sources to be counted, a certain threshold is needed otherwise
the proteins do not seem to be properly utilized by the body. The
following numbers on wikipedia tells us about this threshold:
Essential Amino Acid (mg/g) of Protein
Tryptophan 7
Threonine 27
Isoleucine 25
Leucine 55
Lysine 51
Methionine+Cystine 25
Phenylalanine+Tyrosine 47
Valine 32
Histidine 18
While this threshold exists for complete/incomplete proteins,
I personally believe that if any protein is floating around your body
(regardless of its source) and there is a need for it then it's going
be used.
