Lentils like kala chana can be a challenge to fit into a keto diet because of the extreme focus on avoiding carbohydrates. For a plant-based food, lentils are very high in protein, but they still contain some carbohydrates. If you are a vegetarian attempting a keto diet, you may choose to relax the rules a little bit and include kala chana and other lentils in your diet in order to get the protein you need.