Which Is Better for Protein and Fiber?

Lentils and beans provide similar nutrients with slight variations in protein and fiber content. You can eat both legumes to improve your metabolic and digestive health.

Beans and lentils have very similar nutrient profiles, so it’s challenging to compare them. In fact, whether one wins out over the other for protein and fiber depends largely on the specific type you’re eating.

For example, one study comparing the nutrition of various beans and lentils found:

• Kidney beans had the most protein, while home-cooked green lentils came in second place.
• Canned brown lentils had the least amount of protein.

Another study compared the nutrition of five beans: pinto, navy, great northern, red kidney, and black. Cooked pinto beans had the most protein, while cooked navy beans had the most fiber.

Preparation matters, too. Research has shown that pulses—edible seeds of plants in the legume family, including beans and lentils—have more fiber, protein, amino acids, vitamins, and minerals when they’re home-cooked rather than canned.

Again, the nutrient content of beans and lentils depends on growing conditions, varieties, and cooking methods. However, they have similar nutritional profiles.

Both lentils and beans are considered excellent sources of carbohydrates, fiber, and plant-based protein. They are also rich in magnesium, zinc, folate, B vitamins, selenium, and iron.

 
1 cup (198 grams) cooked lentils
1 cup (172 grams) cooked black beans

Calories 
226
227

Carbohydrates 
38.6 grams (g)
40.8 g

Fiber
15.6 g
15 g

Protein
17.9 g
15.2 g

Fat
0.7 g
0.9 g

Iron
6.6 g
3.6 g

Magnesium
71.3 milligrams (mg)
120 mg

Zinc
2.5 mg
1.9 mg

Selenium
5.5 micrograms (mcg)
2 mcg

Folate
358 mcg
256 mcg 

Potassium
731 mg
611 mg

Nutrition comparison of lentils and beans:

The American Dietary Guidelines recommend eating both beans and lentils. It’s a good idea to mix them up.

Each pulse or lentil has different ratios of soluble and insoluble fibers. They also differ in amino acid profiles, micronutrients (like vitamins and minerals), and other healthy compounds.

Beans and lentils are available canned for convenience, but you can also cook them at home. Pressure cooking cooks beans faster, while lentils are easily boiled in a regular pot. The most popular ways of using beans and lentils are:

• Beans with corn tortillas
• Rice and beans
• Eight-treasure porridge
• Gluten-free recipes
• Dips
• Soups and stews
• Beans and lentils can replace eggs in some recipes
• Bean or lentil tofu
• Pasta with beans and lentils flour
• Bread and muffins with beans and lentils flour

Since both of these pulses are so nutrient-dense, they come with a host of health benefits:

• Support for eye health. Carotenoids are beneficial plant pigments that give lentils their yellow, orange, and red color. Beta-carotene converts to vitamin A, while lutein and zeaxanthin help protect the eyes.
• Better weight management. A meta-analysis found that eating 130 g of pulses daily can help reduce body weight. The decline was significant compared to other weight maintenance and weight loss diets.
• A healthy gut microbiome. Lentils and beans contain resistant starch, which is used in the body as food for good bacteria in the gut. In a study, participants who added a cup of beans to their daily diet for eight weeks saw an increase in beneficial gut bacteria.
• More stable blood sugar. Beans and lentils have a low glycemic index, meaning they do not cause a rapid increase in blood glucose. A small study found mixing rice or instant potatoes with lentils (50-50) lowered blood sugar more than eating rice or potatoes alone.
• Heart health benefits. A meta-analysis found eating beans reduced cholesterol by 19% and the risk of heart disease by 11%. Meanwhile, another study concluded that people who ate lentils had much lower fasting low-density lipoprotein (LDL) cholesterol and total cholesterol levels.
• A well-rounded diet. Most Americans get enough protein, but that’s not the case for fiber. Eating more pulses can help you reach those goals. For example, people should get 14 g of fiber per 1,000 calories in a standard 2,000-calorie diet. One cup of beans provides more than half that amount.

Beans contain compounds, such as phytates, lectins, and tannins, that can reduce the body’s absorption of nutrients. Phytates bind to iron, zinc, magnesium, calcium, and potassium, reducing their absorption. They can also bind to lipids (fats), reducing the absorption of fat-soluble vitamins like vitamin D.

Legumes can cause digestive symptoms in some people. They contain nondigestible carbohydrates, like alpha-galactosides, which your digestive system cannot absorb because it lacks the enzyme to break them down.

Different legumes contain varying amounts of alpha-galactosides. Common beans, soybeans, chickpeas, peas, and lentils have higher levels. These molecules travel to the colon, where bacteria ferment them. This produces gases like hydrogen, carbon dioxide, and methane, which can cause abdominal pain, bloating, distension, and diarrhea.

Several methods can reduce compounds that cause gastrointestinal discomfort. Soaking and cooking dry beans and lentils overnight decreases these molecules, but this method’s success depends on the type of legume, water and salt levels, temperature, and soaking time. Soaking and half an hour of pressure cooking can cut these molecules by 40-90% or more.

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