Which has more protein, beans or lentils?

January 4, 2026 •

4 min read

According to the USDA, a single cup of cooked lentils provides nearly 18 grams of protein, while a similar serving of black beans offers around 15 grams. This comparison immediately raises the question for many health-conscious individuals: which has more protein, beans or lentils?

Quick Summary

Lentils generally contain slightly more protein per cooked cup compared to most beans, though both are powerful sources of plant-based nutrition, fiber, and essential minerals.

Key Points

Protein Content: Lentils typically have slightly more protein per cooked cup than most types of beans.
Iron and Folate: Lentils are richer in both iron and folate compared to black beans and many other bean varieties.
Cooking Time: Lentils cook much faster than most dried beans and do not require prior soaking.
Digestibility: Lentils may be easier to digest for some people, as they contain lower levels of certain indigestible sugars.
Nutrient Synergy: Combining beans or lentils with grains like rice creates a complete protein with all essential amino acids.
Overall Health: Both are nutrient-dense powerhouses, offering high fiber, and significant benefits for heart health, blood sugar control, and digestion.

A Detailed Nutritional Showdown

For those following a plant-based diet, or simply looking to boost their nutritional intake, beans and lentils are dietary cornerstones. Both are celebrated for their high fiber content, essential vitamins, and affordability. However, the question of which offers more protein is a key consideration for many. While lentils hold a slight advantage in protein per cooked cup, the overall nutritional profile and preparation differences are worth exploring to make the best choice for your dietary needs.

Protein Content: The Verdict

When comparing cooked servings, lentils typically offer a higher protein concentration. For example, one cup (198g) of cooked lentils contains approximately 17.9g of protein, while one cup (172g) of cooked black beans contains about 15.2g. The protein content varies significantly among different types of beans, with some, like kidney beans (at around 8.7g per 100g cooked), falling behind lentils on a gram-for-gram basis. It is important to note that the protein concentration in legumes changes dramatically when cooked, as they absorb water. For instance, while raw lentils contain a higher percentage of protein by weight, the cooked values are more relevant for consumption.

Beyond Protein: Other Nutritional Highlights

While protein is a major factor, it's not the only one. Both beans and lentils are nutritional powerhouses, but they offer different strengths.

Iron: Lentils are notably higher in iron, which is crucial for red blood cell production and preventing anemia. A cup of cooked lentils can contain significantly more iron than a cup of cooked black beans.
Folate: Lentils are an outstanding source of folate (Vitamin B9), which is particularly important for pregnant individuals and overall cell growth. Cooked lentils contain substantially more folate than cooked black beans per cup.
Fiber: Both legumes are fiber champions. A cup of cooked black beans offers about 15g of fiber, while a cup of cooked lentils provides around 15.6g. This fiber aids digestion, helps manage blood sugar, and supports a healthy gut microbiome.
Magnesium: Some beans, like black beans, can offer more magnesium per cup than lentils.

Nutritional Comparison: Beans vs. Lentils

Here is a side-by-side comparison based on standard cooked serving sizes, highlighting some key differences:


Nutrient	1 cup (198g) Cooked Lentils	1 cup (172g) Cooked Black Beans
Protein	17.9 g	15.2 g
Fiber	15.6 g	15.0 g
Iron	6.6 mg	3.6 mg
Folate	358 mcg	256 mcg
Magnesium	71.3 mg	120 mg
Potassium	731 mg	611 mg

Cooking and Digestibility: Convenience Matters

For many, preparation time is a practical concern. Lentils are significantly easier and quicker to cook than most beans.

Soaking: Most dried beans, particularly larger varieties like kidney beans, require overnight soaking to rehydrate and reduce potential toxicity. Lentils, by contrast, typically do not require any pre-soaking and can be cooked from dry in about 20-30 minutes.
Cooking Time: Red lentils cook in as little as 5-10 minutes, making them ideal for quick soups and curries. Other lentils take slightly longer, but most are ready within half an hour. Dried beans can take an hour or more to become tender, even after soaking.
Digestibility: Lentils may be more easily digestible for some people. They have a lower content of indigestible sugars compared to beans, which can reduce gas and bloating.

Incorporating Beans and Lentils into Your Diet

There are numerous ways to add these nutrient-dense legumes to your meals:

Soups and Stews: Both lentils and beans are perfect for adding bulk and protein to soups, chilis, and stews.
Salads: Cooked lentils or black beans can be tossed into a salad for a satisfying, protein-packed meal.
Dips and Spreads: Hummus is a classic chickpea dip, but red lentils can also be used to make flavorful spreads.
Side Dishes: Simple rice and beans or a lentil pilaf can serve as an easy, healthy side.
Meat Substitutes: For vegetarian burgers or meatballs, lentils and beans provide an excellent base.
Combining for Complete Protein: As incomplete protein sources, pairing legumes with grains like rice creates a "complete protein" with all nine essential amino acids.

Conclusion: Which is the Winner?

So, which has more protein, beans or lentils? The short answer is lentils, holding a slight advantage in protein content per cooked cup. Lentils also provide more iron and folate and cook significantly faster. However, the choice is not a simple matter of a "winner" and "loser." Both are exceptionally healthy and versatile. Beans offer more variety in texture and flavor, and certain types may be richer in specific minerals like magnesium. Your final choice should depend on your specific nutritional needs, recipe requirements, and cooking time constraints. The best approach is to enjoy a wide variety of both beans and lentils to reap the full spectrum of their health benefits, from promoting heart health to supporting gut function. For further reading on the broader topic of plant-based protein, see this guide on the best plant-based protein sources.

Frequently Asked Questions

No, most beans and lentils are considered incomplete protein sources on their own, meaning they lack one or more of the nine essential amino acids. However, they can be combined with grains, such as rice, to form a complete protein.

For many, yes. Lentils contain lower levels of certain indigestible sugars and phytates than beans, which can lead to less gas and bloating for some individuals.

Lentils generally contain more iron per serving than most common types of beans. This makes them an excellent choice for individuals needing to boost their iron intake, particularly those following a vegetarian or vegan diet.

Both are excellent sources of dietary fiber. On a per-cooked-cup basis, lentils and black beans have very similar fiber content, with some slight variation depending on the specific type.

No, it is not necessary to soak lentils before cooking, unlike many varieties of dried beans. They cook relatively quickly from dry, in as little as 20 to 30 minutes, with split red lentils cooking even faster.

Both are very versatile. Lentils are ideal for soups, curries, and quick salads due to their fast cooking time. Beans are excellent for dishes like chili, tacos, and spreads like hummus, offering a wider variety of textures and sizes.

Not always, as their textures and cooking times differ. Lentils tend to break down and become softer faster, while many beans retain their shape well. You can substitute them in some recipes, but be mindful of the required cooking adjustments.