I did this diet last year. Ate chicken breast or canned tuna + green veg + sugar-free ketchup or mustard 5-6 times a day for 6 weeks. No cheat meals.
Went from 200lbs to 175lbs and lost a good amount of fat (didn't have visible abs before, had visible abs after). The trick is to reverse out of it correctly without blowing up like a water buffalo. You MUST add in a cheat day or start adding calories every couple days bit by bit and fill out. You'll crash your body beating it with low cals and exercise. I also did 30-45mins cardio 5 days a week, as well. Trained 6 days a week I believe... 5 or 6, can't remember.
I balanced out around 180-185lbs with a good set of abs which lasted all summer. Then once it got cold out I put on that protective layer I will start shedding come mid-April.