A friend/coworker did this to the extreme, i think his daily caloric intake to maintain his weight was 2300-2500ish so he cut it to 1000 calories a day. Which is like a bowl of special k, salad and a small SMALL dinner. all while on p90x, he cut alot of weight but i dont know how safe or healthy it is to cut your calories that drastically and you'd probably be really weak after a while.
Your best bet is to research and make your own mealplan and stick to it. Im sure you could hire a personal trainer to help you make one, might be cheaper than seeing them daily too. I use to go to Brianna Tinsley, she was great (read:hot) and cheap.