Wisconsin has a certification law which certifies Dietitians. The law limits the use of certain titles, and giving the impression, implied or direct, for certain practices.
§ 448.76 states that “a person who is not a certified dietitian may not designate himself or herself as a dietitian, claim to provide dietetic services or use any title or initials that represent or may tend to represent the person as certified or licensed as a dietitian or as certified or licensed in a nutrition-related field.