go back to the basics...eliminate processed, junky foods, sodas, etc. If these are in your diet now, just eliminating them will start the process. Drink lots and lots of water.
they have a couple of programs dedicated to losing Regain. I get my protein powder from them (Bariatric Eating, you can also see their website) and it's way better than any others I've had. I'm only 1 week post op but still get good tips from them.