Black Beans vs Soy: How To Choose?

This article explains the key similarities and differences between black beans and soy, foods from the legumes and legume product group. Read on to learn more about the black beans vs soy comparison.
Michael Whaley, Health Writer

Written by Michael Whaley, Health Writer. Updated on January 10, 2023.

Black Beans and soy belong to the legumes and legume products food group, one of the staple food groups for people on a plant-based diet.

Legumes and most legume products are an affordable source of plant protein, dietary fiber, B vitamins, and minerals such as iron, calcium, potassium, and zinc, minerals that are usually harder to get on a plant-based diet.

This article will thoroughly compare black beans and soy and help you learn more about their similarities and differences.

Black Beans

Black beans (Phaseolus vulgaris) are a type of legume that are native to Central and South America.

They are a popular ingredient in many vegan and vegetarian dishes due to their high protein and fiber content and rich, nutty flavor.

Black beans are also a good source of antioxidants. They have been shown to have a number of potential health benefits, including reducing the risk of certain types of cancer and helping to lower cholesterol levels.

They are easy to incorporate into a wide range of recipes and can be enjoyed in dishes such as black bean soup, burritos, and salads.

Black Beans are an excellent source of Vitamin B1 (Thiamine), and Vitamin B9 (Folate).

They also contain a good amount of Vitamin B2 (Riboflavin), Vitamin B3 (Niacin), Vitamin B5 (Pantothenic acid), and Vitamin B6 (Pyroxidine) and some Vitamin K.


Soybeans (Glycine max) are a type of legume native to East Asia.

They are a popular ingredient in many vegan and vegetarian dishes due to their high protein and fiber content. Soy protein is one of the complete sources of a plant-based protein.

Soybeans can be enjoyed in a variety of dishes, including tofu, soy milk, and soy-based meat substitutes, and can also be ground into flour and used in baked goods such as bread and cookies.

In addition to being a tasty and nutritious food, soybeans have been shown to have many potential health benefits.

They are a good source of antioxidants and have been linked to lower cholesterol levels and improved blood sugar control.

Soybeans are also a good source of several important minerals, including iron, zinc, and magnesium.

Soy are an excellent source of Vitamin B1 (Thiamine), Vitamin B2 (Riboflavin), Vitamin B9 (Folate), and Vitamin K.

They also contain a good amount of Vitamin B3 (Niacin), Vitamin B5 (Pantothenic acid), and Vitamin B6 (Pyroxidine) and some Vitamin C, and Vitamin E.

Black Beans vs Soy Nutrition

Now that we’ve described the origin, taste, and usage of these foods, we can move to the most interesting part – comparing black beans vs soy.

This comparison will start by comparing the caloric value of black beans and soy and their macronutrients and then go more in-depth by analyzing their vitamin and mineral content.

Black BeansSoy
Energy341 kcal446 kcal
Carbs62.4 g30.2 g
Sugar2.12 g7.33 g
Fiber15.5 g9.3 g
Protein21.6 g36.5 g
Fat1.42 g19.9 g
Saturated Fat0.366 g2.88 g

Black Beans vs Soy Calories

Most calories in raw legumes come from carbs. Peanuts are an exception here, but they are often considered a nut instead of a legume because of their nutritional profile.

Comparing black beans vs soy for weight loss, black beans are slightly lower in calories, with 341 calories per 100 grams, compared to 446 calories per 100 grams of soy.

However, both black beans and soy can and should be a part of a healthy diet, and neither one shouldn’t be avoided if you’re looking to lose weight.

Black Beans vs Soy Protein

Legumes and most legume products, including black beans and soy, are important sources of plant-based protein.

Soy offer around 41% more protein than black beans.

Soy have 36.5 grams of protein per 100 grams, while black beans have 21.6 grams of protein per 100 grams.

Black Beans vs Soy Carbs

Counting carbs can be important for some people for different reasons, including blood sugar control, weight management, or athletic performance.

It’s also important for people on a keto diet, so let’s compare the carbs content in black beans and soy.

The total amount of carbohydrates is around 52% higher in black beans than in soy. They have 62.4 grams per 100 grams, compared to 30.2 grams in soy.

There’s less sugar in black beans than in soy, 71% precisely.

One handful of black beans (28 grams) contains 0.6 grams of sugar, while the same amount of soy contains 2.1 grams.

Lastly, let’s take a look at the dietary fiber in black beans and soy.

Dietary fiber keeps the digestive system healthy and helps with weight management by promoting a sense of fullness.

With 4.3 grams of fiber per portion, black beans are a better source of fiber than soy which black beans offer 2.6 grams per portion.

Black Beans vs Soy Fats

Like most other legumes, with the exception of lupins and peanuts, black beans and soy are low in fat.

Fats in black beans and soy are mostly healthy unsaturated fats. They are naturally cholesterol-free and trans-fat-free.

Total fat in black beans and soy:

  • Black Beans: 1.4 grams per 100 grams
  • Soy: 19.9 per 100 grams

Speaking of saturated fats, black beans are 86% lower in saturated fats.

Black Beans and soy contain 0.4 grams and 2.9 grams of saturated fat per 100 grams, respectively.

Black Beans vs Soy Vitamins Content

This section will discuss the vitamin content of black beans and soy.

Vitamins are micronutrients, meaning we need only a small amount. However, they are very important for many processes in our bodies.

Black Beans have a higher amount of vitamin A, vitamin C, vitamin B2 (Riboflavin), vitamin B6 (Pyroxidine), vitamin E, and vitamin K.

However, soy have a higher amount of vitamin B1 (Thiamine), vitamin B3 (Niacin), vitamin B5 (Pantothenic acid), and vitamin B9 (Folate).

Black Beans and soy contain the same amount of vitamin D, and vitamin B12 (Cobalamin).

The following table shows the exact amount of vitamins black beans and soy contain side by side, so you can easily compare them.

Black BeansSoy
Vitamin A17 IU22 IU
Vitamin C06 mg
Vitamin D00
Vitamin B1 (Thiamine)0.9 mg0.874 mg
Vitamin B2 (Riboflavin)0.193 mg0.87 mg
Vitamin B3 (Niacin)1.96 mg1.62 mg
Vitamin B5 (Pantothenic acid)0.899 mg0.793 mg
Vitamin B6 (Pyroxidine)0.286 mg0.377 mg
Vitamin B9 (Folate)444 µg375 µg
Vitamin B12 (Cobalamin)00
Vitamin E0.21 mg0.85 mg
Vitamin K5.6 µg47 µg

Black Beans vs Soy Minerals Content

Minerals are important for our body to function properly. We need only a small amount of minerals, so they are called micronutrients.

Some minerals, like iron, calcium, zinc or, iodine, are relatively hard to get on a plant-based diet, so it’s important to choose your foods thoughtfully. This part of the black beans and soy comparison focuses on their mineral content.

Black Beans are a better source of calcium, copper, fluoride, iron, magnesium, manganese, phosphorus, potassium, selenium, and zinc than soy.

On the other hand, soy are a higher amount of sodium.

Check out the table below to learn how black beans and soy compare when it comes to mineral content.

Black BeansSoy
Calcium123 mg277 mg
Copper0.841 mg1.66 mg
Fluoride02.2 µg
Iron5.02 mg15.7 mg
Magnesium171 mg280 mg
Manganese1.06 mg2.52 mg
Phosphorus352 mg704 mg
Potassium1480 mg1800 mg
Selenium3.2 µg17.8 µg
Sodium5 mg2 mg
Zinc3.65 mg4.89 mg

The Final Word

Black Beans and soy are highly nutritious and a great addition to a plant-based diet.

Both black beans and soy are high in specific vitamins and minerals, and including them in your diet will give you the most benefits they offer.

Antioxidants found in beans and legumes can help to protect cells from damage and may reduce the risk of certain diseases and the effects of aging.

Additionally, the fiber and other nutrients in these foods can support the health of the digestive system and may even help to prevent certain digestive cancers.

Legumes are versatile food that can be incorporated into any meal of the day, including breakfast, lunch, or dinner. They can be served hot or cold, making them a convenient and tasty addition to a variety of dishes.


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