Which amino acids do complete proteins contain?

Complete proteins are those that contain all nine essential amino acids in sufficient quantities that the body cannot synthesize on its own and must obtain from food. These essential amino acids play a critical role in various bodily functions, including muscle repair, hormone production, and immune function.

Foods that are considered complete proteins typically come from animal sources, such as meat, fish, poultry, eggs, and dairy products. Some plant sources like quinoa and soy also provide complete proteins. By including all essential amino acids, complete proteins contribute to a well-rounded and nutritious diet, ensuring that the body has the building blocks it needs to maintain optimal health.

In contrast, non-essential amino acids are those that can be synthesized by the body and are not necessarily required from dietary sources. Some proteins may contain only a subset of essential amino acids, which would categorize them as incomplete proteins. Only branched-chain amino acids, while important for muscle metabolism, do not encompass the full range of essential amino acids required from a complete protein source. Thus, the identification of complete proteins as containing all essential amino acids is crucial for understanding nutrition and dietary planning.