What's the difference between an isolate and a meal replacement when it comes to protein supplements. As I often mention, not all supplements are created equally. They aren't all the same. You should decide what your goal is when looking for the right protein supplement for you. Most people think protein is simply for building muscle, which is a myth. Many others think protein supplements are only for those that workout or lift weights, also a myth. I've also heard, 'well I eat meat, ...