Hey there Kari1980
I was on the cookie diet for just over two months and I loved it. I'd lost about 30 pounds. One thing I would caution be very aware of how much working out you did. When I started going to the gym every day on the cookie diet my body went into starvation mode and my weightloss stopped. After a loss in the family, I gained all my weight back and I am not starting all over again. I have been thinking about starting it up again as I'm trying to lose 80 + pounds before March 2013, but think I will try it the old fashioned way. Contact a nutritionist, join the gym by my house and hire a personal trainer.
I wish you the best of luck Kari! It doesn't matter how you do it, at least you are trying to better your life! Kudos to that!