This editorial deals with the specific professional competences of the registered dietician. The dietician might play an essential role in catering and agro-alimentary industry and in large retailers. Furthermore, the dietician has specific qualification in alimentary education in different fields. In the clinical practice, in any case the dietician cannot substitute the physician in diagnosis and in prescribing therapy. His/her role is to promote building the physicians alimentary and lifestyle indications into the individual current habits and behavior, so that the physician prescriptions become actually useful for restoring and maintaining a satisfactory healthy status.