We could tell you our successes on longer fasts, but will that really help? I don't think so. There's plenty of excellent information already out there as well as in the archives.
Fonty and Chris constantly post links to Shelton's book on the soilandhealth website. If you haven't read this yet, then it should be your next step. Once you've read that book, then get back to us and tell us if you need any more motivation (you won't).
Also find the Upton Sinclair booklet on line which I think is also at soilandhealth.
Maybe the fasting forum needs to have a prerequisite that posters have to read the two works above first before posting!!??