A protein bar is a great quick grab for a mid-day snack. Or is it? Not all bars are created equal, and they serve different functions in our diets. With so many out there to choose from, our expert breaks down some of the best bars. Studio 5 Health Contributor Miki Eberhardt shares her thoughts on protein bars in general. Some are great for a meal replacement, but some don't have all the nutrients you need for that. Those bars are better suited as a snack.