High-fiber foods are effective on a low-carb diet because the fiber slows the absorption of the carbs. This slow absorption doesn't lead to a spike and fall in your blood sugar that can result in a craving for more food. In addition to being lower in carbs, boiled lentils also have more fiber than beans. One-half cup of boiled lentils has 7.
Due to their high carb content, legumes are generally avoided on a strict keto diet. In fact, 1 cup (180 grams) of cooked lentils provides 36 grams of carbs. Even when you subtract the 14 grams of fiber, it yields 22 grams of net carbs ( 7 ).
Take a look at the numbers, and it’s easy to see why keto and lentils don’t mix. Lentil carbs per cup (plain and cooked) add up to 39.8 grams total carbs [ * ]. Since they have a little bit of fiber, net carbs in lentils clock in at 24.2 grams for the same amount. How many carbs in lentil soup? Do lentils have carbs if you add them to soup?
Lentils and beans aren't typically the best choices if you're limiting your carbs. However, if both foods are on the menu, a small serving of lentils is likely the better choice for your diet.