Did P90x from New Years through the end of March (roughly 90 days
). It is a good program, but time demanding. The lightest day will be about an hour 15, the longest about an hour and half (YogaX). It is a good program, and if you stick with it you will see results.
As far as nutrition goes, eating more often is important. Get 5 to 6 meals in a day. Don't worry about their crap "recovery drink" schpiel, but don't replace it with Gatorade or some other equivalent high sugar drink either.
Water is your friend.
As for my body fat, I got it down to about 13.4 when on P90x... then spring came... then there were playoff beers 'n wings... Currently sitting at 14.7%, which isn't too bad for an old fart.
Not doing P90x right now as I just can't justify the time commitment with the golfing and the kids and such... doing something else that is only about 45 minutes a day, split between 30 in the morning and 15 in the evening.