TwinCities is right, you can't lose fat in a specific area, except maybe the gut, because proportionally it has more that everywhere else.
Bob is ... umm ... err ... right too (ouch). A no-carb diet drops pounds like a bad habit. It's almost like cheating. Be prepared for three things: 1) You'll have low energy in days 2 to 5, though it will pass, 2) Constipation ... get a stool softener, and 3) Drink lots of water, you'll need it. Carbs are carbo-HYDRATES, their hydration must be replaced.
Chaz is right, lifting is better for what you want than cardio. Better for retaining/building muscle mass of course.
enjolras I dunno ... protein shakes are fine on a zero-carb diet, and they pack huge calories. Besides, I think he wants to just maintain the muscle he has.
I'm not as big a beer-hater as some of these guys ... there is one beer, don't remember which, that has just 5 carbs per 12 oz. You can have three if you lay off all other carbs that day.