Yes, they're varied, and there's a lot of debate about their effectiveness—but Fred DeVito of Exhale Spa is a fan.
"I like to do one at least once a year," he says. "It can jump-start your weight loss and helps the body process nutrients more efficiently. It also 'resets' your taste buds so you are better able to appreciate real, nonprocessed foods."
How to Fast (and Not Want to Die) >>>