i second diet and exercise. thought i would share my experience since i'm currently right in the middle of it:
my wife, who recently gave birth to our first child, was looking for something sensible to knock off the weight. i had been hearing really good things about the "fat smash" diet by Dr. Ian Smith (the guy who does the celebrity fit club tv show) and after buying the $10 book - which took about 1 hour to read and really comprehend - we decided to go for it. that was 16 days ago and i'm down 15 pounds. the program is really about lifestyle change (portion control, excercising, etc), which is the only way you're going to lose the weight and keep it off. there's a 9 day detox period that was fairly tough (no coffee, meat, dairy, alcohol, etc) in the beginning, but it truly has set a good foundataion going forward. i really recommend this diet, or any other one that isn't a gimmick/fad/"yoyo" diet but teaches lifestyle change instead.
oh, and i found out the other day that you can burn more than 2,000 calories walking a single round of golf!
anyway, good luck with whatever you decide upon.
