Many fitness instructors cross the line of scope of practice when it comes to nutrition and diet. We are not supposed to be making specific food choice recommendations. But as Natalie stated, knowledge is important when speaking to any subject with clients. I spend about 3 hours a month researching various diet/nutrition topics for my own use and to give clients advice on the current science of nutrition. But I never tell clients to eat a specific food. For many clients, I refer them to a registered dietician for such guidance. It depends on what the client needs and the client’s goals. Almost all of my weight loss goal clients go to a RD for menu planning.