Trying to figure out who to trust for nutrition information online or who to go to for advice, can be exhausting. It can also lead to you getting wrong or dangerous health advice.

So, who should you turn to for credible advice? A dietitian? A nutritionist? A self-proclaimed "diet expert"?

These terms can be used interchangeably, but there are key differences in the qualifications, regulation, scope of practice, and legal protections for these professionals. In this guide, we’ll break down the key differences to help you separate fact from fiction and make informed decisions about your health.

We’ve based this information on the advice from organisations including the British Dietetic Association (BDA), the Cleveland Clinic, the Association for Nutrition UK, the American Nutrition Association, and the Academy of Nutrition and Dietetics (US).

Dietitian

(RD/RDN - US, RD - UK)

Dietitians are the only nutrition professionals who are regulated by law, both in the UK and the US. They are legally recognised as healthcare professionals. They “assess, diagnose and treat dietary and nutritional problems at an individual and wider public health level”, according to the BDA. Whether in hospitals, clinics, government, or private practice, dietitians offer evidence-based advice targeted to an individual's specific needs or health conditions.

Education & Training

Before obtaining the title of ‘Registered Dietitian’ you must meet certain education and training requirements.

  • US: Dietitians need to earn a master’s degree from an accredited dietetics program as of January 2024. They also need to complete 1,000 hours of supervised practice, pass a national exam, commit to following a code of ethics specific to their profession, and continue professional development through their careers. Some states require Registered Dietitians to be licensed, in which case they will also use the letters LD for Licensed Dietitian.
  • UK: Dietitians need at least a bachelor’s degree (BSc) in Dietetics or a science degree with a postgraduate diploma or Master’s degree in dietetics. They are required to undergo supervised clinical practice in NHS settings, where they must show clinical and professional competence. All dietitians in the UK must be registered with the Health & Care Professions Council (HCPC).

Regulation

  • US: Dietitians are regulated by the Commission on Dietetic Registration (CDR), the credentialing agency for the Academy of Nutrition and Dietetics. RD and RDN are legally protected titles.
  • UK: Dietitians are legally regulated by the HCPC, ensuring they adhere to strict standards and an ethical code. The title of "Dietitian" is protected by law.

Key Takeaway

If you’re looking for professional, medical-grade nutrition advice, a dietitian (RD/RDN in the US, RD in the UK) is your best choice. Their training and credentials ensure that their recommendations are grounded in science and tailored to your health needs.

Nutritionist

(US and UK)

Nutritionists provide advice about healthy eating and nutrition education, and can work in various roles, but their scope of practice is narrower compared to dietitians. They might work in non-clinical roles like public health, education, the food industry, sports nutrition, or research.

While some nutritionists may be highly educated, others may not have formal qualifications, and the title "nutritionist" is not legally protected in either country. Anyone can call themselves a nutritionist and legally give nutrition advice either in person or online. So it’s important to understand the different levels of education that fall under this category.

Education & Training

  • US: The term "nutritionist" can be used by anyone, regardless of formal education. However, some nutritionists may hold advanced degrees in nutrition and/or dietetics, such as a B.S. or M.S. in Nutrition. Registered Dietitian Nutritionists (RDNs) are both dietitians and nutritionists, but not all nutritionists are RDNs.
  • UK: Similarly in the UK, many people study Nutrition at Bachelor's, Master’s and PhD levels but this is different to studying dietetics. It is less clinical and may often have a focus such as public health nutrition or sports nutrition.

Regulation

  • US: The term "nutritionist" is unregulated, anyone can call themselves a “nutritionist” regardless of their training and education. However, those with a Certified Nutrition Specialist® (CNS) credential are more regulated. CNS will have an advanced degree in nutrition (graduate or doctorate) from a fully accredited university plus 1,000 hours of a supervised internship and must pass the exam administered by the Board for Certification of Nutrition Specialists. It is the most widely recognised nutrition certification by federal and state governments.
  • UK: The title "nutritionist" is not protected by law in the UK either, meaning anyone can use it without formal registration. However, nutritionists can voluntarily register with the UK Voluntary Register of Nutritionists if they meet the required educational standards, which includes completing an accredited degree in nutrition. Registered Associate Nutritionists (ANutr), have typically graduated with a BSc (Hons) or MSc in nutrition science within the last three years. Registered Nutritionists (RNutr) are seen as more credible as they must have demonstrable experience of degree-level, evidence-based practice in a specialist area of nutrition such as nutrition science or public health. Both have committed to adhere to the AfN Standards of Ethics, Conduct and Performance.

Key Takeaway

The lack of legal regulation means that anyone can call themselves a nutritionist, so check for credentials. Look for Nutritionists who have the credentials CNS (US), ANutr (UK), or RNutr (UK) or hold advanced degrees. In certain areas, their formal training, especially clinical training can be limited compared to dietitians.

Medical Professionals

Other medical professionals, such as doctors and nurses, may also provide nutrition advice as part of their overall healthcare practice. However, they typically receive limited formal training in nutrition during their education. While their advice can be valuable, particularly in managing medical conditions where diet plays a role (e.g., diabetes, heart disease), their expertise in nutrition is generally not as comprehensive as that of a dietitian or registered nutritionist. For in-depth and personalised nutrition advice, especially for complex conditions or dietary changes, it is often best to consult with a dietitian, as they are specifically trained to provide evidence-based nutrition guidance.

Some medical professionals may have taken extra training in nutrition and lifestyle medicine, such as Dr Idz who has a Master's degree in Nutritional Research and Dr Shireen Kassam who is a board-certified lifestyle medicine physician.

Social Media Nutrition and Diet ‘Experts’

The explosion of social media has given rise to many self-proclaimed "diet experts" and influencers. These individuals may have little to no formal training in nutrition, yet they often promote specific diets, supplements, or lifestyle changes. Anyone can call themselves a diet expert or nutrition coach, with or without qualifications.

Others may have a degree in a scientific field, and use this to justify their advice on nutrition and health, but this doesn’t necessarily give them the right expertise to provide accurate advice about nutrition and health. For example, Jessie Inchauspé, the self-proclaimed ‘Glucose Goddess’, claims that controlling blood sugar spikes will solve a range of effects on our health. Jessie makes reference to the fact that she is a biochemist, but that doesn’t qualify her as a health professional or to understand the nuanced links between food, blood sugar spikes, and the effects on health.

Her claims have been debunked by experts like Dr Nicola Guess, a Registered Dietitian and PhD, who focuses her work on type 2 diabetes. One of the claims Jessie made was that glucose spikes cause mitochondrial dysfunction, but using the skills most likely gained during her dietetics training and PhD, Dr Nicola Guess pulls apart this claim and shows that it’s not true.

Influencers such as Candi Frazier aka ‘theprimalbod’ may use titles like "Certified Functional Nutrition Therapy Practitioner," but these qualifications are not as rigorously regulated as those for dietitians or registered nutritionists. These titles can provide her audience with a sense of  security in her advice, despite her videos often containing false claims, misrepresenting or misinterpreting the studies she cites.

While some social media influencers may offer helpful tips or share their own experiences, it’s critical to verify their qualifications before following their advice. Relying solely on unqualified individuals can lead to misinformation, which may be harmful to your health.

Can you trust everyone with the right qualifications?

In general, while professionals with dietetics training, a PhD, or a medical degree provide better quality, more accurate advice, they are not immune to spreading misinformation. People such as Paul Saladino MD and Anthony Chaffee MD will frequently cite the fact they are medical professionals while making false claims about ‘toxic’ vegetables, among others.

On the other hand, there are also influencers who provide reliable, researched, and nuanced nutrition and diet advice who don’t have a formal qualification such as Ben Carpenter and Graeme Tomlinson aka The Fitness Chef. A good way to spot this is in both cases, neither Ben nor Graeme make wild or exaggerated claims about foods, instead their advice feels more nuanced and balanced.

Conclusion

When it comes to nutrition advice, credentials matter.

Dietitians are the most qualified and regulated professionals, providing evidence-based recommendations. Registered Nutritionists (RNutr in the UK) also offer reliable advice but with less clinical focus. Nutritional therapists, diet experts, and social media influencers should be approached with caution, especially when dealing with medical conditions. Always check the qualifications of anyone offering nutrition advice and choose professionals who are properly trained and regulated.

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