What is the complete protein for definition?

A complete protein is a protein source that contains all nine essential amino acids that the human body cannot synthesize on its own. These amino acids are crucial for various bodily functions, including tissue repair and muscle building. Complete proteins are typically found in animal-based foods like meat, fish, eggs, and dairy, but can also be present in certain plant-based sources like quinoa and soy. Consuming a variety of proteins can help ensure adequate intake of all essential amino acids.