A lot more often than you might think.

The American Dietetic Association (eatright.org) suggests seeing a registered dietitian if you have diabetes, cardiovascular problems, or high blood pressure. You should also consult a registered dietitian if you are contemplating gastric bypass surgery, if you have chronic digestive problems, if you’re an athlete seeking to improve performance, or if your child is having growth problems, said Emily Werner, a registered dietitian at the Joslin Diabetes Center in Boston. Many pregnant women also benefit from a consult with a registered dietitian.