If you pay attention to your diet, chances are you’ve debated the two most common diet duos: Good fats and bad fats; good carbs and bad carbs. Well, today we’re switching gears and spotlighting protein for a change.
You see, not all sources of protein are created equal. Proteins are made of building blocks known as amino acids, 9 of which are essential—meaning our bodies cannot produce them, and we must get them from the foods we eat. These essential amino acids are what differentiates “complete proteins” from “incomplete proteins.”
What is a complete protein?
A complete protein is food that provides all 9 of the essential amino acids in high enough amounts for our bodily functions. Typically, complete proteins are animal-based foods, such as meats, poultry, fish, milk, eggs, and cheese. Fun fact: soybeans are considered the only plant-based complete protein, containing all 9 of the essential amino acids.
What is an incomplete protein?
An incomplete protein is a food that is low in one or more of the essential amino acids. Incomplete proteins include grains, fruits, vegetables, nuts, and seeds.
Are animal-based proteins better than plant-based proteins?
While most complete proteins are animal-based foods, you don’t need to be a carnivore to get all of your essential amino acids. In other words, plant-based proteins are not necessarily inferior to animal-based ones. In fact, vegetarian diets are commonly associated with better health outcomes such as lower risk for heart disease, blood pressure, type 2 diabetes and lower BMI.
Still, if you’re vegetarian or vegan, it’s important to be mindful of the types of foods you’re eating to make sure you’re getting the right balance of essential amino acids. The key is to eat a variety of plants, and to pair plant-based protein sources to get the right balance. By combining two or more incomplete protein foods you can create a complete protein meal and get all the essential amino acids your body needs. The idea behind combining is to eat grains that are low in lysine and high in methionine, with legumes (think: beans, peas, peanuts, and more), which are low in methionine and high in lysine. This way of eating is also known as “complementing”—and you might already be doing it!
A few incomplete proteins that become complete sources when combined:
Rice and beans
Peanut butter on whole wheat bread
Mac n’ cheese
Rice and lentil curry
Tofu and millet
Bean and barley soup
Cornbread and black eyed peas
Hummus and pita bread
Yogurt and nuts
Final verdict: Do you need complete proteins?
The short answer is no. Eating a combination of incomplete proteins will provide all of the essential amino acids your body needs. And no, you don’t have to eat the complement protein foods at the same meal. It’s perfectly okay to eat your rice now and munch on beans later. Just one more reason why a varied diet is a healthy diet!