You need education to become a nutritionist. Experience is what you acquire after you're hired.
Step 1: Find out what the requirements are in your state, or in the state in which you plan to practice. There are 30 states that require a license and 15 states that require certification (1 requires registration after an accredited course). Generally, the requirements for state licensure and state certification include having a bachelor's degree in food and nutrition or a related area, supervised practice, and passing an exam.
Step 2: Find a program. The accreditation required for a degree in the nutritional science field varies from state to state. At this time, 46 states require an accredited 2 or 4 year degree in nutritional science (either online or campus-based.) Getting your bachelor's in nutrition, institution management, biology, chemistry, and physiology is your best bet.
You'll also benefit from business, mathematics, psychology, sociology, and economics courses. Odds are, if your program is a good one, it will touch on all these bases. And if your state is one that requires a license with experience, it's best to pick a program that has a built in internship.
Step 3: Consider acquiring an advanced degree in nutritional science. An advanced degree isn't strictly necessary, but a solid understanding of biology, chemistry and health will be a great asset. In addition, the more education you have, the more job opportunities you'll have.
If you get an advanced degree, you can take the CBNS (Certification Board for Nutrition Specialists). If you take and pass this exam, you will become a Certified Nutrition Specialist.
If you choose not to continue your education, you can still take the Boards for Certified Clinical Nutritionist and this doesn't require an advanced degree.
Step 4: Complete the CNCB's coursework requirements. The CNBC (Clinical Nutrition Certification Board) requires anatomy and physiology, chemistry, microbiology, human biology and biochemistry. There are also 8 nutrition-related electives and you must complete 5 of them.
Step 5: Take the CCN Exam. When you've taken all the courses, the PGSCN, and submitted all your paperwork, you're good to apply to sit for the CNN. Once you've passed the CCN exam, you're a Certified Clinical Nutritionist.
Step 6: Get licensed! Find the licensure requirements for your state by visiting the website of the Commission on Dietitians and Nutritionists. Submit the necessary paperwork and whatever your state requires.
Why not go all the way and become a Registered Dietitian? They are more employable, more knowledgeable and have a lot more prestige.