Which of the following foods are complete proteins?

• A. Rice and beans
• B. Corn
• C. Egg, meat, cheese, meat, poultry, fish, soy
• D. Bananas

Answer: (C)

Complete proteins provide all nine essential amino acids in adequate amounts. Animal-derived foods—eggs, meat, cheese, poultry, and fish—are classic complete protein sources because they supply the full spectrum of essential amino acids. Soy is also considered a complete protein among plant sources. Rice and beans, while they can form a complete amino acid profile when eaten together, are not a single food item that supplies all essentials on its own. Corn does not provide all nine essential amino acids in sufficient amounts, and bananas offer little protein overall. Therefore, the foods that are complete proteins are eggs, meat, cheese, poultry, fish, and soy.