What are complementary proteins, and how do we get them?

We know that getting protein in our diet is important for our health, but why? Proteins are part of every cell, tissue and fluid in our bodies. Proteins are made from amino acids, which can be thought of as building blocks. The body uses 20 different amino acids to make its proteins. There are some amino acids that the body cannot make in required amounts. These are called essential, and they must come from the diet.

Complete protein foods have all the essential amino acids. In general, animal foods such as meat, poultry, eggs, dairy and fish are complete protein sources. Incomplete protein sources have only low amounts of some of the essential amino acids. Combining two or more foods with incomplete proteins, to form complementary proteins, can provide adequate amounts of all the essential amino acids. Complementary proteins do not need to be eaten together, so long as the day's meals supply them all.

Here is a list of some food pairings that make a complete protein:

• Legumes with grains, nuts, seeds or dairy
• Grains with dairy
• Dairy with nuts
• Dairy with nuts/seeds and legumes

And here are some common meal items that naturally complement each others' proteins:

• Beans and rice or tortillas
• Peanut butter sandwich
• Macaroni and cheese
• Tofu with rice (or any grain)
• Hummus with pita bread
• Grilled cheese sandwich
• Yogurt with nuts
• Noodle stir-fry with peanut or sesame seed sauce
• Lentil soup or dairy-based soup with bread
• Whole grain cereal with milk
• Pizza
• Lasagna
• Tacos filled with beans or lentils
• Quinoa salad with black beans and feta

Protein is essential to life. So, just as the rhyme "I love you once, I love you twice, I love you more than beans and rice" suggests, get complementary proteins in your diet by enjoying some beans and rice with someone you love.

- Shelly Guzman, dietetic intern, and Debra A. Boutin, MS, RD, former chair and dietetic internship director, Department of Nutrition and Exercise Science at Bastyr University