Legumes and Beans in a Low-Carb Diet

Nutritional Value and Preparation Tips

Show Article Table of Contents

Beans and peas
enviromantic/Getty Images

Smaller servings of beans and legumes, such as chickpeas and lentils, are encouraged on the South Beach Diet and other low-carb diets. They are not only an excellent source of fiber, vitamin, minerals, and other nutrients, they are less likely to affect your blood sugar because they are slowly digested and contain resistant starches that are not readily absorbed by the intestines.

Nutritional Value

By definition, a legume is a plant or seed that belongs to the family Fabaceae. The legume fruit itself is a pod filled with dry seeds that can either be consumed or used for feed. These include a variety of dry beans and dry peas but exclude green beans and green peas which are considered vegetable crops. 

The nutritional value of a one-half cup serving of cooked, unsalted legumes can vary, although they all tend to deliver a higher percentage of protein per calorie.

Calories (per gram) Carbs (per gram) Protein (per gram) Fiber (per gram)
Adzuki beans 147 28.5 8.65 8.4
Black beans 114 20.4 7.6 7.5
Black-eyed peas 99 17.8 6.6 5.6
Broad beans (fava beans) 94 16.7 6.5 4.6
Chickpeas (garbanzo beans) 134 22.5 7.3 6.2
Edamame 94 6.9 9.2 4
Field beans 114 21.3 6.2 8.3
Great Northern beans 104 18.7 7.4 6.2
Green peas 67 12.5 4.3 4.4
Kidney beans 112 20.2 7.7 5.7
Lentils 115 20 8.9 7.8
Lima beans 108 19.6 7.3 6.6
Mung beans 106 19.3 7.1 7.7
Navy beans 127 23.7 7.5 9.6
Pinto beans 122 22.4 7.7 7.7
Soybeans 148 7.2 15.7 5.2
Split peas 116 20.7 8.2 8.1
White beans 124 22.5 8.7 5.6

Like other plant-based foods, legumes contain no cholesterol and have little fat or sodium. There is also evidence that the daily intake of legumes may help lower blood pressure and reduce low-density lipoprotein (LDL) cholesterol.


While all types of legumes and beans can be included in a low-carb diet, you should steer well clear of any that are made with sugar or lard. This includes baked beans, which are often packed with brown sugar and molasses, and split pea or bean soups, which are sometimes made with fat back.

While peanuts are technically a legume, for the purpose of a low-carb diet, they are considered a nut. The recommended serving size of peanuts on the South Beach Diet is between two-thirds of an ounce to an ounce. Two tablespoons of natural peanut butter (no added sugar or oil) are also allowed.

Canned Versus Cooked 

Generally speaking, canned beans tend to raise blood sugar more than those that are soaked and cooked at home. The only exception is soybeans which already have a low carb count and low glycemic index (GI)

Canning requires extremely high pressure that breaks down the starches in beans and makes them more accessible in the digestive system. By doing so, it can remove some of the key benefits of the resistant starch (which include maintaining the intestinal flora and normalizing bowel movements). 

Preparing the Beans

Cooking dry beans at home is easy and help ensure that you retain the maximal health benefits. With the exception of lentils and split peas, dry beans will need to be soaked for at least a couple of hours before cooking.

Soaking help soften the beans, making them easier to cook and digest. It also helps remove some of the excess starch which can ferment in the intestines and cause bloating and gas. Larger beans especially will benefit from an overnight soak. Adding salt to the soak may also shorten the cooking time.

There are two basic ways to soak a bean: 

  • The traditional way is to soak them for four to 12 hours in a pot or bowl filled with water two inches above the level of the beans. If salting, use one tablespoon of table salt or two tablespoons of coarse salt per pound of beans. Drain and rinse before cooking.
  • If you are in a hurry, place the beans in a pot and cover with two inches of water. Add salt and bring to a boil. When the boiling point is reached, turn off the heat and let sit for an hour. Drain and rinse before cooking.

If you choose not to soak the beans, be sure add another hour or two to the cooking time.

Cooking the Beans

Once soaked, the beans can be cooked to whatever recipe you choose. You can either use a slow-cooker or cook them on the stoveto[p. While cooking, always be sure to cover the beans with two inches of liquid and to replace the liquid as it reduces. Always cook on a low temperate and avoid stirring too much, which can break down the beans and release excess starch.

Smaller beans like lentils or split peas may take 30 minutes to an hour to cook. Others can take anywhere from three to six hours depending on their size. The beans are done when they are tender but not mushy. One cup of dried beans will yield around three cups of cooked beans.

The cooking liquid will often be tasty and can be stored in the freezer for up to six months. When needed, simply defrost and use the liquid as the base of a vegetarian soup or stew. 

Was this page helpful?
Article Sources