What Does a Nutritionist Do for You?

If you’re trying to improve your diet, manage a chronic health condition, or just feel better in your body, you may have considered looking for professional nutrition help. 

But as soon as you start searching, it gets a little confusing—do you need a nutritionist, a dietitian, or someone with “RDN” after their name? Understandably, you may wonder what these terms mean and who’s the most qualified to help.

For a TL;DR summary: Nutritionist isn’t a regulated term, while Registered Dietitians (RDs) are licensed, highly trained experts in evidence-based nutrition. 

In this article, we’ll explain what a nutritionist does, the areas they can help, and what to look for when choosing someone to support your health journey.

What Is a Nutritionist?

In the U.S., the term nutritionist isn’t legally protected. That means anyone—regardless of education, training, or experience—can call themselves one. In some states (like California), even your gym receptionist or favorite TikTok influencer could technically use the title.

That doesn’t mean all nutritionists are unqualified—some truly do have degrees or certifications. However, without regulation, there’s no guarantee.

If you’re looking for someone with legitimate credentials, check for the Certified Nutrition Specialist (CNS) certification. A CNS must complete the following: 

• Master of Science or doctoral degree in nutrition, public health, biochemistry, or another related field 
• 1,000 hours of supervised practical experience
• Pass a board examination 

The most significant difference between an RD and a CNS is that RDs are always qualified to provide medical nutrition therapy (MNT) to manage chronic health conditions (like heart disease or diabetes) through diet, while only certain CNSs may provide MNT, depending on state regulations.

Overall, CNSs do not have the same legal recognition or nationwide licensure as RDs. The scope of practice can vary by state, and in some places, CNSs might be able to provide MNT if they work with a collaborating physician. 

The bottom line is that a CNS is much more qualified than your average “nutritionist” but not as universally recognized as an RD.

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Nutritionist vs. Dietitian: What’s the Difference?

Although the terms “nutritionist” and “dietitian” are often used interchangeably, they aren’t quite the same thing.

While all dietitians are nutritionists, not all nutritionists are dietitians.

To become an RD, you need:

• A bachelor’s degree in nutrition or dietetics (as of 2024, a master’s is also required)
• Coursework in biochemistry, anatomy, physiology, culinary science, nutrition counseling, medical nutrition therapy, and more
• 1,000-1,200+ hours of supervised practice in clinical and community settings 
• To pass a national board exam

If you want to verify someone’s credentials as a Registered Dietitian, look up their status here. 

What Can Nutritionists Do?

In general, nutritionists are people who help others improve their diets.

However, the title “nutritionist” is not legally protected or consistently defined in most states or countries. 

Nutritionists might provide help such as:

• Basic meal planning 
• Nutrition advice
• Habit change 
• General wellness coaching 

But because the title isn’t regulated, nutritionists have no standardized scope of practice. What they can legally do depends entirely on state laws, individual credentials, and licensure (if any).

What Can’t Nutritionists Do?

The scope of practice for nutritionists is more limited than that of RDs. 

Nutritionists without a license (i.e., not a CNS) cannot:

• Provide medical nutrition therapy (MNT) 
• Practice in clinical settings (like hospitals) 
• Bill insurance for their services 
• Prescribe medications or supplements
• Diagnose or treat diseases 

The Bottom Line: Should You See a Nutritionist?

If you’re generally healthy, don’t need chronic disease management through nutrition, and don’t mind if someone doesn’t have extensive clinical experience or nutritional education, a nutritionist might be fine for you. 

But if you’re dealing with chronic health issues and want verified credentials, it would be best to look for a CNS or RD/RDN. These protected titles ensure you’re working with someone qualified, certified, and legally allowed to offer personalized, evidence-based nutrition care.

Talk to a Registered Dietitian Nutritionist.