The title "Dietitian" is protected in the UK — only those registered with the HCPC (Health and Care Professions Council) may use it. "Nutritionist" is not a protected title. A client agreement clarifies the scope of services, the limitations of nutrition advice vs medical treatment, and data protection obligations.

• Dietitian: HCPC-registered protected title
• Nutritionist: unprotected — qualifications vary widely (check UKVRN registration)
• Medical advice: nutritionists cannot diagnose or prescribe medication
• Referral: serious medical conditions must be referred to GP
• GDPR: dietary and health information is special category data

Legal reference: Health and Social Care Act 2012 (HCPC); UK GDPR Article 9; Food Standards Agency