Personally tailored advice. When you see an RD or RDN, the last thing you'll get is one-size-fits-all diet advice. "A dietitian is like an investigator seeking to learn about your current and desired state of health," says McDaniel. "At your initial visit, expect to do a lot of talking while the dietitian does a lot of listening." After learning about your health history, favorite foods, eating and exercise habits, an RD or RDN will help you set goals and prioritize. Follow-up visits will focus on maintenance and monitoring your progress.