As people were getting ready for the holiday season and its accompanying waist expansion late last year, Dr. Mehmet Oz let viewers of his TV show in on a timely little secret. "Everybody wants to know what's the newest, fastest fat buster," said the board-certified cardiothoracic surgeon and one of People magazine's sexiest men alive… So how are we supposed to tell medicine from miracles? As a general rule, said Victor Montori, an evidence-based medicine guru at the Mayo Clinic, "If studies are cited, then this cannot be, at the same time, a secret revealed just to you now. If the studies are any good, the effects are usually very small." Referring to Oz's holiday weight-loss advice, he added: "It is very unlikely that an important compound hidden in the garcinia could have a big effect."
Slate by Julia Belluz and Steven J. Hoffman