Protein bars are very similar to protein powder in that they are used for the same reason. The difference is in the delivery of the protein, a bar doesn't need to be mixed with a liquid, and it is small enough to carry around in your pocket and consume anywhere A Pure Protein bar can be used as a high protein, low carb and low fat meal replacement, a snack, or a way to get protein when you aren't home and can't mix the protein powder. Protein bars come in different carb/ protein ratios depending on your fitness goals.