I lost 65 lbs. since December.
In the Army we said, "The important things are always simple, and the simple things are always hard." Losing weight is really as simple as this: calories out > calories in. I have a couple more rules to clarify some minor points:
1) Your body tends to "homeostasis", i.e., status quo. You must vary your calories +/- 10% minimum to gain/lose weight.
2) You can't exercise all the way to skinny town. Most of your calories are burned just breathing, thinking, and making big molecules out of small ones... exercise alone will *not* work.
3) Lose fast at the start, but then slow down the rate of weight loss. This is so you can get motivated by your progress, but if weight comes off too fast (like it did with OP's ulcer) then it will come right back later -- and it will bring a few friends.
Any weight loss program that allows healthy eating WILL work for someone who is 1) sufficiently motivated, and 2) not suffering from a hormonal condition.
As a metabolic research student (PhD) and someone who lost the equivalent weight of a couple of children... I think I've learned a thing or two about it!
Losing it is easy, keeping it off is the hard part. I like the other poster's idea of having a "line-in-the-sand" weight that you must never, ever cross under pain of death! Ok, not death, but, seriously, don't frickin' cross it, or else!!
Remember those annoying word-things for the SAT, where this is to that as the other is to some other thing? Scales are to weight what hydrometers are to brewing... it's essentially not an option if you want to make progress.
