What to do about appealing

I've received my denial letter from my insurance company ( Aetna ) two days ago.  They said I was denied because I did not show 6 or 3 months of supervised diet in my submitted paperwork.  I had my doctor fax me over that information and now the question I have is should I or do I need to go through the whole appeal process or should I just submit the information they are questioning.  The problem I am having is that my doctor is not very detail when it comes to documenting and I am afraid that what she has faxed to me may not be enough for them.  Should I just fax them over the paperwork or do I need to go through the appeal process?

I believe that once you have been denied you must go thru an appeal. Call your insurance company and question them. I am surprised that everything was not submitted. Did you or your doctor not know what was needed to submit and therefore submit less than complete info?