A dietitian is a regulated health professional trained to assess, diagnose and treat diet-related problems, including medical conditions, while “nutritionist” is a broader title that, in many countries, isn’t protected by law. In the UK, the British Dietetic Association explains that dietitians are the only nutrition profession with statutory regulation: you must be registered with the Health and Care Professions Council (HCPC) to use the title. Registered Nutritionists (RNutr) are qualified in nutrition science and sit on a voluntary register, but anyone can call themselves a nutritionist. For advice on a medical condition, a registered dietitian is usually the right choice.
The main differences
| Registered dietitian | Registered nutritionist (UK) | Unregistered “nutritionist,” “nutritional therapist” or “health coach” | |
|---|---|---|---|
| Title protected by law? | Yes, in the UK and many other countries | The “Registered Nutritionist” title is controlled by a voluntary register | No |
| Training | Accredited dietetics degree with supervised clinical practice | Accredited nutrition science degree | Varies from none to a short course |
| Works with medical conditions? | Yes, including in hospitals | Mainly general health and public health, not medical treatment | Shouldn’t diagnose or treat medical conditions |
| Regulated by | HCPC (UK); state boards and the CDR (US) | Association for Nutrition (UK) | Usually no one |
What dietitians do
In the UK, the BDA says dietitians must complete an undergraduate or postgraduate dietetics degree, or a degree apprenticeship, accredited by the HCPC and BDA, including 1,000 hours of on-the-job training. They’re qualified health professionals who assess, diagnose and treat dietary and nutritional problems for individuals and at public health level, and many work in the NHS.
In the US, the Academy of Nutrition and Dietetics explains that registered dietitian nutritionists (RDNs) need at least a graduate degree from an accredited program, must complete supervised practice and pass a national exam, and must keep up continuing professional development. Some also hold specialist credentials in areas such as kidney disease, sports nutrition or pediatrics.
Dietitians commonly help with:
- Diabetes and prediabetes
- Kidney, liver and heart disease
- Digestive conditions such as irritable bowel syndrome, coeliac disease and inflammatory bowel disease
- Food allergies and intolerances
- Eating disorders, as part of a treatment team
- Nutrition during cancer treatment, after surgery or with tube feeding
- Malnutrition in older adults
What registered nutritionists do
In the UK, the Association for Nutrition runs the UK Voluntary Register of Nutritionists. A Registered Nutritionist (RNutr) must show nutrition science knowledge to at least honors degree level and, typically, at least 3 years of evidence-based professional experience. The BDA notes that registered nutritionists need an accredited degree in nutrition science, without compulsory on-the-job training like dietitians.
Registered nutritionists often work in public health, universities, the food industry, sports nutrition, education and general wellbeing. They’re well placed to give evidence-based advice on healthy eating, but not to treat medical conditions with diet on their own.
Why “nutritionist” can be confusing
Because the plain title “nutritionist” isn’t protected in many countries, people with very different training use it: a scientist with a nutrition degree, a dietitian, or someone with an online certificate. The same goes for titles such as “nutritional therapist,” “nutrition coach,” “wellness coach” and “diet expert.” Some are well trained; others promote supplements, tests or diets without good evidence.
How to check someone’s credentials
- UK dietitian: search the public register on the HCPC website.
- UK registered nutritionist: search the Association for Nutrition’s register for RNutr or ANutr.
- US: look for the RD or RDN credential and check your state’s licensing board.
- Elsewhere: look for your country’s dietetic association or regulator.
- Ask directly what qualifications they hold and who regulates them.
Warning signs
Be cautious if a practitioner:
- Promises that diet alone will fix serious medical conditions.
- Sells their own supplements as part of the advice.
- Uses unproven tests, such as hair analysis or food intolerance blood tests sold online, to diagnose problems.
- Tells you to stop prescribed medicines.
- Recommends extreme diets or long fasts without medical supervision.
Our guide to reading nutrition headlines explains how to judge health claims.
What to expect at an appointment
A first appointment with a dietitian or nutritionist usually lasts 45 minutes to an hour. Expect questions about:
- Your health, any diagnoses, medicines and recent blood test results.
- What you usually eat and drink in a day, and your eating pattern.
- Your work, sleep, activity and cooking habits.
- What you’d like to change, and what has or hasn’t worked before.
You should leave with a few practical, realistic goals rather than a rigid meal plan, and a plan for follow-up. Keeping a food diary for a few days beforehand can make the appointment more useful. A good practitioner works with your doctor where needed and explains the reasons behind their advice.
Cost and how to get seen
In the UK, NHS dietitians are free, usually through a referral from your GP, hospital team or health visitor, though waiting times vary. Private dietitians and registered nutritionists charge their own fees. In the US, many health insurance plans cover nutrition counseling for some conditions, and Medicare covers medical nutrition therapy from a registered dietitian or nutrition professional for people with diabetes or kidney disease, or who’ve had a kidney transplant in the last 36 months, with a doctor’s referral.
When to see which
- You have a medical condition or take medicines that diet could affect: see a registered dietitian. In the UK, your GP can refer you.
- You want general advice on healthy eating, sports nutrition or weight: a registered dietitian or registered nutritionist can help.
- You’re worried about disordered eating: see your doctor first. An eating disorder is serious but treatable, and if you need someone to talk to now, findahelpline.com lists free helplines in many countries.
Common questions
Can a dietitian call themselves a nutritionist?
Yes. A registered dietitian is also trained in nutrition, so many use both titles. A nutritionist can’t call themselves a dietitian unless they’re registered as one.
Are dietitians available on the NHS?
Yes. NHS dietitians work in hospitals and community services, usually by referral from a GP or specialist.
Is a nutritional therapist the same as a nutritionist?
No. Nutritional therapists usually practice complementary approaches, and their training varies. Check their qualifications and regulator before booking.
This article is general information, not medical advice. Talk to your doctor or a registered dietitian before making big changes to how you eat, especially if you have a health condition, take regular medication, or are pregnant or breastfeeding.
