Sports Nutrition Consultant

Hey MFT, just wondering what are the best organizations to become a certified nutrition consultant.I know that I want to become a person trainer and get certified form the NSCA but I'm not sure where should I get certified to become a sports nutritionist consultant. I'm also would like to know, what are the differences between a dietician, nutritionist, sports nutritionist,nutrition consultant and etc. I know that they are all similar, they all plan nutrition programs, give nutrition advice, and etc but what is the big difference between all of them.