Cleansing’s more recent popularity is traceable to the 1990s, when Peter Glickman, the Scientologist and entrepreneur, repackaged a 1940s diet called the Master Cleanse (which)...involves lemon juice, cayenne pepper, maple syrup and 10 days of your life. Celebrities as varied as Beyoncé, Jared Leto and the Moore/Kutchers (Demi and Ashton were tweeting about it this week) swear by its energizing and weight loss effects, weight loss being not all that surprising, when you consider that you are essentially sucking lemons and a few teaspoons of sugar for 10 days. And the diet has a glorious circular logic to it. As Mr. Glickman explains on his Web site, if you experience symptoms like cravings, fatigue, irritability, headaches, pains, nausea, vomiting, hot bowel movements (!) ... congratulations! That means you were supertoxic, and the cleanse is working.
...
That green juice? It was like drinking everything bad that ever happened to me in high school.
...
it’s dumb. “Many people are undiagnosed diabetics, and these cleanses can cause spikes and crashes in blood sugar levels that could be quite dangerous,” said Nancy Kalish, a certified health coach in Brooklyn who advises clients against juice cleanses. “In addition, even if you have nothing wrong with you, this kind of cleansing puts a lot of stress on your body. Your body wants and expects food. And as with most crash diets, which is really what this is, your body thinks it’s starving. It doesn’t know it’s going to get more food. So it lowers your metabolism, and if you do this enough, it can lower your metabolism permanently.”