I also have all of my clients on MyFitnessPal! It is a non-intrusive way for me to help keep up with their nutrition and cardio. They also have app’s for iPhone and Android, so there is never any excuse on why they cant enter their food 🙂
For the first few weeks I just focus on letting them learn to enter everything and give them a chance to realize how many calories they are actually eating to help them understand how they got to where they are. After that we start making small adjustments to their daily routines, then slowly making lifelong changes.
I have had the best success with clients that really do buckle down and use the program pretty religiously. Most of my clients are only with me 3 hours a week, they understand its what they do for the other 165 hours in the week that makes a huge difference.