If you are just starting out on the Pilates, you will not be able to do them every day from the start. If you do them right, you will need recovery time! I've been doing them for about a year and I do them 2 or 3 times a week and I need the recovery days. Also, I alternate tapes. I started with 2 and rearely do the same Pilates routine twice in a row. Healing after excercise is part of the process! You could use weights as additional strength training.
As for diets, look at what your vices are. I never keep ice cream in my fridge or go near donut shops! I'm working on that myself.