Lentils: As vegans and vegetarians know, lentils pack a powerful punch of protein, fiber, and minerals while containing comparatively few calories and almost no fat. A cup of cooked lentils offers 22 grams of protein, about 300 calories, and less than 1 gram of fat. Lentils are also relatively quick to prepare for a meal or snack, and because they soak up the flavors of whatever they’re cooked with, they can make a tasty base for many dishes.