And, your average speed kicks mine to the curb! I assume you've been to a doctor about the weight. With the amount of miles and the speed you're riding, I can't begin to fathom why the weight isn't falling off. Some of your recent weight gain might be muscle gain, because of the weightlifting and ab work -- muscle weighs quite a bit more than fat. Are you sure there isn't something metabolic going on? Again, this just seems to drastic, especially for someone so committed to fitness.
(Whenever I see a documentary on folks going through the surgery, they never seem to be doing anything to actively try to lose weight, by either exercise or diet. I yell at the TV, "Go ride a bike -- that's all you need to do!" So, it's hard to understand why you can be doing everything right and still not losing weight.)