My insurance company is Blue Cross Blue Shield for Federal Employees. I had to follow a 3 month doctor supervised diet, have 2 years documentation of being obese, my BMI was high enough that I didn't need a comorbidity listed, but we did have documented in my medical record that I was insulin resistant, had a few episodes of high blood pressure, and joint pain. I kept a 3 month log of activity, meal plan and vital signs (blood pressures and pulse) and turned it in to add to my medical record. I really think this helped them see that I was serious about sticking with the plan. I had to be seen and evaluated by a psychiatrist and nutritionist. I met with a personal trainer (that wasn't required) and had them make a plan for me too to show the surgeon and insurance company. I was literally approved in 24 hours and I was stunned. I hope you get approved soon too.
Take care,
Jen