Alright:
There are three layers of people involved here.
Firstly, there is this Australian lady who had a morbid obesity issue and tried many and varied diets etc to no avail. She then tried her own strategy - including motivational elements - and succeeded in dramatically reducing her size, pretty much at a level that you see periodically on TV.
My friend is a friend of hers and found out that she tried to write a book about it, but she has no talent in that space. It really needs a rewrite. My friend is an entrepreneur and is willing to cough up dollars for publishing and marketing the book. However, he needs a ghostwriter to make the deliverable work.
I am not just a friend of this fellow, I am also a publisher (co-owner, and Chief Editor), and I have agreed - given quality - to handle epublishing and trade paperback level publishing of the deliverable. I also offered to help get the word around to find a ghostwriter.
I don't think this is an onerous task for a good specialised writer, and I also don't think this is a big gig. Consequently, this is not a big buck thing, but on the other hand it would be good money for the timeframe involved.
My role is to advertise, and any interested parties will be filtered by myself and I would then give those writers the contact details of my agent friend.
I hope this helps - it is pretty much all I know.
Gerry