For the most part yes. When dealing with nutrition, health and fitness, you should have certifications. Not only to follow requirements but to help with the creditbility of your business. I have friends(they all are always helping me to get into a healthy routine), who run a fitness center, are fitness trainers, nutritionists and another into natural health nutrition. They have all gone through certifications, training and some are degreed in their relevent field.
What I would suggest is to check with your local college...I did and was certified as a personal trainer and it was a 3 month course.The cost is pretty resonable. And you may learn something that you did not know. I have helped 2 of these friends with there forms and information, so if you ever need information, just let me know. Or I can give you a contact to one to ask questions to see what is involved. Even if you become a certified coach and deal with weight issues and planning you should be certified. It will not only help your creditbility in the field, you will gain knowledge and follow state regulations. I know that WIT has courses nationwide. When you start building out your business, let me know, i would be happy to share some information and forms with you.