Registered Dietician (RD/RDN)
Accredited degree + internship + board exam. Licensed to diagnose and provide medical nutrition therapy (insurance often covers). Can legally assess, diagnose, and treat nutrition issues.

Certified Nutrition Specialist (CNS) and Certified Nutritionist (CN)
Master’s or Doctorate + 1,000 hours of supervised practice and passing of a national exam.

Certified Functional Nutrition Counselor (CFNC)
Trained in systems biology and root causes. 10 mos + exam through the Functional Nutrition Alliance (FxNA). Looks at the “why” behind symptoms. Uses food and lifestyle education to empower client to connect the dots. Does not diagnose, treat, or prescribe. Example: Helping you link gut health to energy, mood, and sleep — then supporting habit change. (Suzanne Trainor is a CFNC)

Nutritionist
In California and many states, the title of “nutritionist” is unrelated. Anyone can use the title, even without training. Always check education and credentials.