V.C.
I am not familiar with that plan. The other post mentioned eating only 1200. If that is what the plan calls for and you are training for a half marathon, you will definitely be burning muscle as well as fat and messing up your metabolism. If you clean up the eating you should lose weight training for the run.
Otherwise if the plan will work for you go for it. The information on the website looked ok.
As a personal trainer, I use another plan developed by sports nutritionists. You can let me know if you want info on it.
Victoria