How Do Different Legumes Compare in Protein and Fiber?

Although all legumes are relatively high in protein and fiber, there are clear differences among them: lentils and chickpeas stand out for their protein content, while dried beans and borlotti beans stand out for fiber. These differences can help guide which legumes to choose for different meals.

Which legumes stand out for protein? Cooked red and green lentils contain about 9 grams of protein per 100 grams, making them one of the legume group’s highest-protein options. Chickpeas are similarly high in protein. These 2 legumes are often chosen as a main protein source in kitchens looking to reduce meat consumption.

Which legumes stand out for fiber? Dried beans and borlotti beans have more fiber than lentils. Their higher fiber content can help prolong fullness, and their thicker skins absorb water more slowly, so they also take longer to cook than lentils. The fiber-rich skin of borlotti beans also makes foam in the cooking water more noticeable than with lentils.

How does soaking time affect nutritional value? As soaking time increases, the phytic acid content of legumes decreases. Phytic acid is a compound that can somewhat hinder the body’s absorption of minerals such as iron and zinc. That is why properly soaking chickpeas and dried beans, which require longer soaking, can make them easier to digest and improve mineral absorption; lentils have thinner skins and need much less soaking. Cooking method also affects nutritional value: boiling legumes for too long can cause some water-soluble vitamins to pass into the cooking liquid. Using that liquid as a soup or sauce base can partly offset this loss. Canned legumes are usually packed in liquid with a high sodium content, so drain and rinse them.

In practice, including different legumes in a meal plan for one week—for example, lentil soup on one day, a chickpea dish on one additional day, and dried beans on yet another day—adds variety in both protein and fiber. Relying on only one type of legume can mean missing out on the different nutritional balance offered by others. Medium-sized legumes such as peas and borlotti beans offer a balance of protein and fiber: they are neither as high in protein as lentils nor as high in fiber as dried beans. Soybeans are distinct among legumes because they have substantially more protein and fat than other types, which is why they are a main ingredient in products such as plant-based milk and tofu.

The volume of a serving of cooked legumes also affects nutritional comparisons. A bowl of boiled lentils generally absorbs more water than the same volume of dried beans, so it may have a lower protein density by volume. Comparing dry weight rather than cooked weight gives a more consistent comparison.