I am at NAS fallon (navy). I haven't sent in my papers yet, I still have to do the nutritional evaluation but I lost it when they tried to tell me I needed to go back on weight watchers so they could document it. I called tricare and the guy said that it doesn't say specifically a time frame to do it. I printed the policy, had Weight watchers send me a copy from where I did it 3 months in the past on my own with little progress and my doctor wrote it in my medical records so it's documented.
Like I said, I haven't been approved yet but I don't see any reason why I won't be because I have tried and it isn't my fault that my doctors suck and wouldn't help me after I expressed my desire to lose weight. Since they wouldn't help I did it on my own and that should be enough to get me past the attempts to lose weight prior to requesting surgery. The surgeon that would be doing my surgery requires you to lose a percent of your body weight before surgery as well just to further prove you are serious about this.
You should also be sure to tell them about any gym memberships you have had, if you did slim fast or just a general low calorie diet or something no as marketed as weight watchers or jenny craig. Everything you've ever done to lose weight should be mentioned to your doctor.