How should I prevent myself from gaining weight after liposuction?

I am finally getting liposuction and am very excited. My concern though is that I will just gain all the weight back after liposuction. I have had small successes with diet and exercise but I am not as active as I once was. Please tell me that once the fat is removed with liposuction it cannot be gained back with poor diet decisions!

SJones

F, 47, District of Columbia