chunkyd... I think a documentary is a really interesting idea. A lot of my problem with weight loss (or lack of) over the years was with exercise. I just didn't like it. In cycling I finally found a sport that I really enjoy and that I can participate in as a heavier person.
Yes I am trying to use it as a weight loss tool but at the same time it is very freeing to me to be able to get on a bike, pedal, enjoy it and know it's good for me. Yes, I'm slower up the hills, yes I use more gears, yes I breathe heavier but I still can do it. I proved it to myself last year by cycling my first century.
I think your idea could end up being a very powerful and motivating experience for many.
Best of luck and keep us posted!
Gypsy (from the Athenas
)