I am not familiar with the American Association for Nutritional Consultants or their certification program for CNC. Don’t know what this certification would enable one to do or the educational qualifications that would enable one to apply. It appears that all you have to do is take an open book test to qualify. According to Quackwatch, the AANC and the CNC certificate are bogus.
I am aware that most states license who can provide nutrition services, including Pennsylvania. Contact your state licensure board to determine what the qualifications are to practice nutrition counseling in your state. There are 46 states that license who can provide nutrition services. The Academy of Nutrition and Dietetics’s Commission on Dietetic Registration has a list of all license boards.