there is a difference between fasting and starving. the two concepts are easy to decipher. on one hand you are controlling when you break the fast, on the other you have no choice but to starve due to lack of food..
the longest I have fastest was 19 days. you can find my log where i talk about it
i could have kept going, but the social aspects of fasting make it hard to.. food is such a big part of our society. tailgating at a game, going out to dinner, cooking, going to your favorite grocery store and picking out a steak, etc.. these are all things you have to sacrifice when you fast