you have to understand that not a lot of lab testing has being done on the *actual* benefits of fasting, some yes but very little 'documented' evidence of any 'permanent' benefits. there are mounds of testimonies from people claiming their bodies functioned better after one (for while) but also plenty claiming they didn't.
and as eager to believe, as many fasters are, that all toxins consumed during one's life can be removed by fasting and/or will remain locked in our fatty tissues till old age if we don't, there are still no tests proving this.
in fact i'm still searching for definitive proof that pesticides, preservatives and artificial food coloring s etc are excreted in 'larger' quantities via the bladder, bowel and skin during a fast than when not fasting ..or that distilled water 'only' leaches out inorganic minerals (considering everything is organic - chelated by vegetables or not) but does not leach out organic minerals. like where's the *actual* evidence?
one can find can plenty of websites and books written by people *claiming* these marvelous things happen but that's not actual proof! and given humanity's track record, one would have to be a total idiot to blindly *believe* *anything* we say! we are liars (unless your one of those who still thinks de nial is a river in egypt). the fact is most egos are either wannabe gurus or making a living promoting the benefits of their product regardless of proof, so of course they want you to believe them, they get something out of it!
and don't forget why medical Science arose in the first place, it was to free us from snake oil merchants and all the other ridiculous cures humans are prone to indulge in without proof. like using the bile of those poor bears for one and the fins of millions of sharks, another. we are m*o*o*ns. Medical research now costs every nation HEAPS to ensure the safety of its citizens (and other species) from the crap we indulge in.
LOOK for the tangible experiential facts if you wish to become a healthy sensible human being. theres enough blind followers out there already, destroying the human body and the planet without you helping. don't blindly depend on one persons hearsay. get the tangible experiential facts and most of all experiment for yourself.
facts are marvelous because every time we do discover one, then hurray! it sets us free from another blind belief. beliefs (fervent *wishes* only, that something be so) they are what primitive cultures live by when they don't have the facts. but you can, so go get em. then you'll discover that once you know the *actual* fact of something its pointless to continue laying a belief on top of it. facts speak for themselves. facts is far safer than beliefs.
one thing most people do agree on is their bodies worked better after a fast - for a while - but then less food also does that. and as long as they are careful especially after a long fast and don't burst an artery exercising before the fatty membranes of the epithelial arterial cells have strengthened and wait until their platelets and immunoglobins have returned to normal, then the body should remain healthier if eating more vegetables than it was prior.
of course fasting can start up an addictive cycle of overeating ...even healthy foods... or become a crutch for a junk binge if you aren't careful. so beware.
and of course none of this would happen if one just used one's brain and cared enough to eat a healthy Diet all one's life. but thats a bit too much to ask of this primitive species at the mo, its STILL too busy fancying itself as a loving (ahem) spiritual being in crystal ball fairyland.