RD versus Nutritionist
I would say about a quarter of the people I talk to aren't sure what the term "dietetics" means.
A subset of them also don't know 'dietitian' when I elaborate further. This is why I wish the term 'nutritionist' was regulated -- because almost everyone knows what that term is, but they don't usually know what's behind it.
Registered Dietitian/RD/RDN - someone who can administer Medical Nutrition Therapy and has been trained according to a set of regulations and is bound by a code of ethics
Nutritionist - someone who decided to call themselves a nutritionist
You can see where the issue is... I'm not trying to discredit those with formal nutrition training (i.e. my professor who isn't a dietitian, but has a PhD in nutrition. Clearly, she knows what she's talking about). Rather, it has become trendy to be able to give nutrition advice -- personal trainers, yoga instructors, zumba instructors, life coaches... everyone wants to be able to also be a nutritionist! And why not? It's easy enough: take a nutrition course online, and BAM you're in. On the flip side, there are people who fall into the categories above who aren't just looking to expand their resume, but actually want to provide better advice to their clients.
In order to sort of "reclaim" this term, RDN has become the more prominent abbreviation behind dietitian's names, meaning Registered Dietitian Nutritionist, so that the lay public know what we do and can recognize us. I don't blame people for not knowing the difference--I only vaguely know what differentiates the geek squad at Best Buy from any of the other blue shirts who I can ask a question (because usually it's a basic thing like "can this cord also carry sound.") I'm sure my boyfriend, a computer science engineer, would find this frustrating.
Having said that, while these people would certainly not be hired at a hospital without their RD credential, they are the ones in the private sector, consulting, and working in corporate wellness. But what makes RDs so special? Well, starting in 2020, every RD2Be will have to have a master's degree. And we have to participate in a national matching process with a chance of less than 50% of actually getting an internship. Without one, you can't qualify for the RD national exam, and you can't practice. If you get an internship, you're lucky if it costs only a few thousand dollars. While there are a few highly competitive internships that give you a living stipend and don't cost money, most give no stipend and cost thousands of dollars (mine was $8,000). Future RDs pay the money because we love what we do and are passionate about it--we recognize that it will take a long time to pay off student loans (undergraduate and graduate school) and recoup our internship costs. It's similar to social work -- you don't go into the field expecting to have a lot in your savings account, you go into the field to educate and make a difference.
If you don't match, you can be a nutritionist. For some people, knowledge in nutrition is all they need. I have friends going into policy--they don't need an RD for that, but knowledge of nutrition can make them exponentially better policy makers. I have friends going into global health--the RD credential is only for the US, so why spend money on an internship when you can make a bigger difference going right into global healthcare?
Overall, the landscape is messy.
I can't say that only RD's are knowledgeable -- that's simply not that case. But scope of practice has some very blurry lines, even in the RD world. Sometimes we are put in counseling situations that require a therapist and it's our job to recognize that and refer as necessary. I expect that as time continues, tensions will only intensify in the field. The biggest impact I can make is voting for protection of my credentials, and differentiating myself from others who also claim that they can give you good, maybe better, care.