You probably know that protein plays a vital role in overall health. After all, the macronutrient is found in literally every cell in the body. If you’re looking to optimize your protein intake, though, it’s important to understand that not all proteins are created equal. In fact, some protein-rich foods are much more digestible than others. Read on to learn about the most digestible protein sources you can consume.
All About Protein Digestibility
The term “protein digestibility” refers to how well our bodies are able to absorb and use the proteins we consume, says Sarah Koszyk, R.D.N., author of 365 Snacks for Every Day of the Year. “It predicts how many amino acids—the building blocks of protein—can be put to use by the body after the protein source is digested and absorbed,” adds dietitian Katherine Brooking, R.D., founding partner of nutrition marketing and communications firm AFH Consulting.
The body requires 20 amino acids in order to survive and nine of them—referred to as essential amino acids or EAAs—can only be obtained from food. “So ‘complete proteins’ are those foods with all nine EAAs,” says Brooking. Since complete protein sources (sometimes referred to as a “high-quality” or “whole” protein) provide the body with every type of EAA the body needs, it is one factor in determining a food’s digestibility.
That said, specific amino acids have a better absorption rate after digestion than others, which also impacts a protein’s bioavailability—or ability to be used by the body, Brooking and Koszyk explain.
Put these factors together and you get the Protein Digestibility Corrected Amino Acid Score (PDCAAS), a measurement that’s been the standard for assessing a protein’s quality since 1989. A score of 1.00 is the highest attainable mark, indicating that a food offers the highest-quality protein and is easy for the body to digest and utilize.
The Most Digestible Protein Sources
While the average healthy adult doesn’t need to stress about how their favorite protein-packed foods score on the digestibility scale, protein digestibility can be pretty important for certain groups of people, including children, the elderly, those with food intolerances, those who limit or avoid animal products, those suffering from food insecurity, and athletes (who tend to supplement their diet with additional protein).
Here are the four most digestible protein sources—the top two animal-based and top two plant-based—on the protein digestibility scale.
1. Greek yogurt
Protein per serving: 16.1 grams per 5.5-ounces
“Greek yogurt receives a top-rated score due to its high-quality milk, casein, and whey proteins,” says Koszyk. “It contains branched-chain amino acids, which bypass the liver and go straight to the muscles for optimal repair and recovery.”
Greek yogurt is also a good source of vitamin B12 (which aids in the function of the central nervous system) and zinc (a nutrient that boosts the immune system to fight off bacteria and viruses), Koszyk adds.
Add it to your diet: Koszyk’s favorite way to enjoy Greek yogurt is in a parfait with fresh fruit and crunchy granola. “I also like using Greek yogurt to make creamy dips, such as spinach dip or onion dips, instead of using sour cream.” (She opts for plain, by the way.)
Protein per serving: 6.24 grams per whole egg
“Eggs contain all nine essential amino acids, providing complete protein in every bite,” says Koszyk. They also contain numerous other nutrients, such as vitamin A (for better vision), vitamin D (necessary for strong bones), vitamin E (an immune-boosting antioxidant), B vitamins (for the formation of red blood cells), selenium (for reproduction and thyroid function), calcium (for healthy bones and teeth), and folate (to help the body make new cells).
Add it to your diet: Koszyk recommends snacking on a hard-boiled egg after a workout. Otherwise, “enjoy a frittata with vegetables for breakfast, lunch, or dinner or add an egg to a bowl of ramen or soup for an extra savory kick.”
Protein per serving: 8.1 grams per 8-ounces
“Soy contains all nine essential amino acids and is found in numerous foods, such as edamame, tofu, and soy milk,” says Brooking. Plus, “most of the fats in soy are polyunsaturated (including important omega-6 and omega-3 fats) and these fats can be good for your heart and help lower your chances of certain diseases when part of a balanced diet.”
Read More: 5 Plant Foods That Are Complete Proteins
Add it to your diet: “One of the easiest ways to consume soy is by making a soy milk smoothie with your favorite leafy greens and fruit.” Try this basic recipe: four ounces of soy milk, two cups of spinach or kale, two cups of ice cubes, and two cups of fresh fruit (like pineapple).
4. Pea Protein
Protein per serving: 24 grams per one level scoop of NOW Foods Pea Protein Powder (other brands vary)
“I like pea protein because it contains iron, an important mineral for vegetarians and vegans,” says Brooking. “Plus, this protein is naturally vegan, gluten-free, dairy-free, and does not contain any of the top eight food allergens—peanuts, tree nuts, eggs, fish, shellfish, cow’s milk, wheat, or soy.”
Add it to your diet: “I always toss a scoop into my smoothie,” says Brooking. Try this blend: one scoop of pea protein mixed with one and a half cups plant-based milk, half a banana, and a pinch of ginger, cinnamon, cardamom, and black pepper.