If you're innovative and have something with some science behind it that's not made it to mainstream health & fitness yet, AND you go in with the right approach I think you'd stand a chance. Too many people try to go there with some plain product or a prop blend of Dr. Oz'ish ingredients and they just get roasted. And rightfully so. I believe it would be very possible to take something that's starting to get some legs (no pun intended) in the bodybuilding world and use Shark Tank to push it mainstream.
Of course, you better have your science down or you'll still get roasted. I always found it amusing how they crucify supplements by saying "You're selling something that people INGEST, how can you be sure it's safe?" - but when someone comes on with some other next-best-thing food or drink product that you're still ingesting, they don't seem to worry too much about the safety, manufacturing processes, etc.