You guys need to eat less sodium (salt) it makes you retain water (you drink it, but you don't pee it out)
Common culprits are lunch meats, sausage, baccon, tuna, cheese, and adding salt to your meals. Reducing some of these should help alot.

And for a quick fix, if I'm going out and need my bloated belly to go away, I have a cup or two of coffee a few hours before I go out. It clears the water right out of me. Caffeinated works better but you're not supposed to have caffein on Atkins, and decaf works just fine too, just not quite as well as regular.

Good luck!