What is a primary source of complete proteins?

Complete proteins are those that contain all nine essential amino acids that the body cannot synthesize on its own. Animal foods, such as meat, fish, eggs, and dairy, provide these essential amino acids in sufficient quantities, making them primary sources of complete proteins. Additionally, soy products, such as tofu and tempeh, are unique among plant sources in that they also provide a complete amino acid profile.

This means that when looking for sources of complete proteins, both animal-derived foods and high-quality plant sources like soy are vital. In contrast, vegetable sources generally lack one or more of the essential amino acids, and processed foods can vary widely in nutritional content, often lacking the balance of amino acids found in whole foods. Fats and oils do not contain proteins, as they are primarily sources of energy and fatty acids. Thus, the combination of animal foods with soy products distinctly qualifies as a primary source of complete proteins.