Final answer:
Complementary proteins are proteins that complement each other's amino acid profiles and supply the missing amino acids. They do not need to be consumed together in the same meal but should be included in the daily diet for a complete intake of essential amino acids.
Step-by-step explanation:
Complementary proteins are proteins that complement each other's amino acid profiles. They are called complementary because they supply the amino acid(s) missing in the other protein. For example, if a grain lacks an essential amino acid, a legume can provide that amino acid, making the combination of grain and legume a complete protein. Complementary proteins do not need to be consumed together in the same meal, but rather on a daily basis to ensure a sufficient intake of essential amino acids.