A good friend of mine had this done last year, has lost around 40kg, exercises heaps and has the fitness level of an elite athlete.

I think she can eat almost anything except for really tough to digest stuff like steak. She followed the instructions to the letter in terms of chewing, not drinking anything with meals. She knows someone else who didn't follow the instructions and who hasn't lost any weight.

It was another BB member called Sushee's posts that opened my eyes to the benefits of lap band surgery - the fact that some people just don't feel full so find it very hard to lose weight. You might want to have a look for those - I think you'd find them really informative.