Timeline: A History of Single-Food Diets
See also: Can man live on fruit alone? Read more about fruitarianism.
The Diet: Salmon two to three times a day for three days, with sides of fruit, veggies, or oatmeal. Devised by dermatologist Nicholas Perricone to combat inflammation—a possible cause of weight gain—and wrinkles.
The Die-hards: It reportedly hooks Bruce Willis and Heidi Klum.