This is a new evangelical program we had seen yesterday on TBN and it seems like inspired by Christotherapy : "Forty day fast!" of a guy named Gregory Dickow. Here is a reference to the program:

http://pathsofrighteousness.blogspot.com/2008/03/forty-day-fast.html

(see also http://thinkingfast.org/ or http://www.fromtheinsideout.us/ )

It seems fairly fundamentalist and simplicistic. Of course, the eternal question in these positive thinking programs as for mind-fasting too, is: who will decide what it a 'good' and what is a 'bad' thought?

One cannot avoid the painful and sometimes tiresome art of discernment that couuld be aquired an maintained only by constant practice, exercise, and by reliance on a dialog with an objective forum (Church, doctrine, ethos, guide etc.). This objective forum somehow should have a regulatory and advisory role for the subjective factors (what I feel right, what attracts me or what I don't like) that provie the "prime matter" for discernment.