A one-tablespoon serving of nutritional yeast is only 20 calories and offers three grams of protein. Add it to salads, steamed broccoli or kale, sautéed tofu, roasted veggies, or cooked whole grains or pasta. Sprinkle it on popcorn instead of butter and also use nutritional yeast to make vegan cheese sauce for mac and cheese. It's an easy way to quickly get a little extra protein and B vitamins.