What to Eat With Beans to Make It a Complete Protein

December 31, 2025 •

4 min read

Historically, the idea that plant-based eaters needed to perfectly combine complementary proteins at every meal to achieve a "complete" protein was widely accepted. While modern understanding shows that eating a variety of plant foods throughout the day is sufficient, pairing beans with other foods remains an effective and delicious strategy to ensure a full spectrum of amino acids.

Quick Summary

Beans are incomplete proteins lacking methionine, but combining them with methionine-rich foods like grains, nuts, or seeds creates a complete protein. These pairings provide all nine essential amino acids necessary for the body's functions.

Key Points

Combine with Grains: Pair beans with rice, corn, or whole-wheat bread to create a complete protein, as grains are rich in the amino acid methionine that beans lack.
Add Nuts and Seeds: Sprinkle seeds like sesame, sunflower, or pumpkin over a bean dish, or use nut butters for a methionine boost.
Don't Stress About Same-Meal Pairing: Your body pools amino acids throughout the day, so you don't need to consume complementary proteins in the exact same meal to reap the benefits.
Explore Traditional Cuisines: Many traditional global dishes, like rice and beans or tortillas with refried beans, naturally form complete proteins.
Embrace Variety: A diverse diet that includes a mix of legumes, grains, nuts, and seeds over the course of a day is the best approach for a balanced amino acid intake.
Consider Dairy: If you are not vegan, combining beans with dairy products like cheese or sour cream also effectively creates a complete protein.

Understanding Incomplete and Complete Proteins

Protein is made up of amino acids, and there are nine essential amino acids that our bodies cannot produce, so we must obtain them from our diet. A complete protein source is a food that contains all nine of these essential amino acids. While animal products typically contain all nine, most plant-based foods are considered 'incomplete' because they are low in one or more. For example, legumes, including beans, are rich in lysine but are low in methionine.

To create a complete protein, you simply need to combine a methionine-deficient food like beans with another food source that is rich in methionine. This doesn't need to happen at every single meal, as your body is capable of pooling amino acids from various foods eaten throughout the day. However, creating complementary pairings is a traditional and nutritionally sound practice found in many world cuisines.

Classic Combinations with Grains

Pairing beans with grains is a time-tested method for creating a complete protein. Grains are generally high in methionine, perfectly complementing the lysine-rich profile of beans.

Rice and Beans: This is perhaps the most well-known complementary protein combination, a staple in many cultures worldwide. Brown or white rice combined with black, pinto, or kidney beans provides a full amino acid profile.
Corn and Beans: In traditional indigenous cuisines, corn and beans (part of the 'Three Sisters' agricultural system) are a powerful combination. Corn is high in methionine, while beans provide the necessary lysine.
Whole-Wheat Bread and Beans: Spreading refried beans or hummus on whole-wheat toast or tortillas makes for a quick and easy complete protein meal.
Lentils and Barley: While lentils are technically legumes, they share a similar amino acid profile with beans. Pairing lentils with a whole grain like barley in a hearty soup or stew delivers a complete protein source.

Perfect Pairings with Nuts and Seeds

Nuts and seeds are excellent sources of methionine and can be easily combined with beans in various dishes to form a complete protein.

Beans with Seeds: Toppings like sunflower seeds or pumpkin seeds sprinkled over a black bean salad or chickpea dish can create a complete protein profile.
Peanut Butter on Whole-Grain Bread: Peanuts are legumes, and when combined with whole-grain bread, they form a classic, delicious, and complete protein source.
Hummus and Sesame Seeds (Tahini): Hummus, made from chickpeas (a bean), is often mixed with tahini, a paste made from sesame seeds. This classic pairing creates a complete protein that's perfect for dipping with whole-wheat pita bread.

Dairy and Other Sources

For those who include dairy in their diet, combining beans with dairy products is another way to achieve a complete protein.

Chili and Cheese: A classic chili made with beans and topped with cheese provides all the essential amino acids. The dairy supplies methionine, complementing the beans.
Bean Burrito with Sour Cream: A burrito filled with beans, wrapped in a whole-wheat tortilla, and topped with a dollop of sour cream or yogurt is a complete protein meal.

Comparing Complete Protein Pairings


Combination	Bean Type	Complementary Food	Methionine Source	Recipe Examples
Rice and Beans	Black, Pinto, Kidney	Rice (White or Brown)	Rice	Burrito bowls, traditional rice and beans
Corn and Beans	Black, Lima	Corn	Corn	Succotash, bean and corn salad
Beans and Seeds	Black, Chickpeas	Sunflower, Pumpkin, Sesame Seeds	Seeds	Salads, chili, hummus with tahini
Whole-Wheat Bread and Beans	Refried, Black, Kidney	Whole-Wheat Bread	Whole-Wheat Bread	Tostadas, sandwiches, wraps
Peanut Butter Sandwich	Peanuts (legume)	Whole-Wheat Bread	Whole-Wheat Bread	Peanut butter and jelly sandwich
Chili and Cheese	Kidney, Pinto	Cheese (Dairy)	Cheese	Chili con queso, chili bowl

The Role of Variety

While the concept of deliberate protein pairing is a helpful tool, the most important takeaway for plant-based eaters is to consume a wide variety of foods daily. If you have a bean burrito for lunch and oatmeal with nuts for breakfast, your body will have access to all the amino acids it needs. Focusing on a diverse diet featuring legumes, whole grains, nuts, and seeds is the most reliable way to ensure you're getting all essential amino acids without the need for strict meal-by-meal pairing.

Conclusion: Fueling Your Body with Smart Pairings

Beans are a highly nutritious and versatile food, but they need a complementary food to provide all nine essential amino acids in one meal. By combining them with grains, nuts, or seeds, you can easily create a complete protein source. From classic pairings like rice and beans to more creative combinations like a black bean salad with sunflower seeds, there are endless delicious ways to fuel your body with high-quality, plant-based protein. The key is variety and balance, ensuring your diet includes a range of plant-based sources throughout the day to meet all your nutritional needs.

Visit the National Peanut Board to learn more about how to create complete protein from plant foods.

Frequently Asked Questions

A complete protein is a food source that contains all nine essential amino acids, which our bodies cannot produce and must be obtained from our diet.

No, it is not necessary to eat complementary proteins in the same meal. Your body can effectively combine amino acids from different foods eaten throughout the day to form complete proteins.

Beans are incomplete proteins because they contain lower amounts of the essential amino acid methionine compared to other amino acids.

Yes, some plant-based foods are naturally complete proteins, including soy products (tofu, tempeh, edamame), quinoa, buckwheat, and chia seeds.

A simple example is peanut butter on whole-wheat toast. The peanuts (a legume) are complemented by the whole-wheat bread (a grain) to form a complete protein.

Yes, as long as you eat a varied diet that includes a mix of legumes, grains, nuts, and seeds, you will likely consume all the necessary amino acids over the course of the day.

Grains are typically rich in methionine, the amino acid that beans are low in. By combining them, each food provides the amino acids that the other lacks, resulting in a complete protein.