To become a registered dietician, you need to complete some type of undergraduate degree (preferably in the nutrition field, but not required). In addition, you need to complete a required sequence of "DPD" courses at an ADA accredited university. These DPD courses are required and are similar at most accredited universities (they include nutrition courses, lots of science courses, and some management courses). You must complete these courses and receive a verification statement from the director of the program at the university. You must then complete a dietetics internship (usually runs about 10 months, unpaid, approx. 40 hrs per week, including clinical rotations, community rotations, food service admin, etc-). The internships are done through some universities and some companies (look on the ADA website for the list of accredited schools and internship programs). After completing the internship you can sit for the RD exam. Once passing the exam, you need to also do continuing education to renew your RD status.
Its a really long process, but the RD is really the only credible nutrition certification. I'm in the process right now, and its a lot of work.
