I send my people to a friend of mine who is a credentialed nutritionist. I find that sort of relationship is great, as it can work both ways. I don’t have a nutritional credential, so I tend to speak of nutrition in rather general terms for those students who need/want it.
I have recommended myfitnesspal for people who want a way to ‘journal’ food intake for themselves.
I also steer clients toward myfitnesspal. It’s a good, general tracking system that lets you check in on them and give them tips and ideas on how to improve. They can customize the daily calorie goal, etc. to their specific situation. It has a huge database and analyzes not only the macro nutrients, but also vitamins/minerals. They can check on their progress throughout the day, which helps them stay on track.
However, they need to be very careful when logging, as many of the entries are user submitted and are not complete or accurate. The best way is to use the scanner tool that automatically inputs the product’s nutrition info.
It’s certainly no replacement for a full blown nutritionist/RD consultation, but provides decent guidelines and is free.