Becoming a nutritionist (R.D.)

I'm interested in becoming a nutritionist that is also an R.D. I would like to enroll in a graduate program for this in the near future. I was also considering doing a dual major in something such as business just in case I ever want to open a private practice. Would I be taking on too much or is it possible if I really work well at balancing out my schedule? I plan to go part-time. I would really like to hear some experiences from people who have taken this path. What were the classes like, how long did it take, what types of things should I expect? Thanks