Susan Powter (born 22 December 1957) is an Australian-born motivational speaker, nutritionist, personal trainer and author, who rose to fame in the 1990s with her catchphrase “Stop the Insanity!“, which was the centerpiece of her weight loss infomercial.
Her platinum-white flat-top haircut,aggressive manner of speaking and being barefoot while speaking in public, became an element of her celebrity. She has since grown out her hair and has multiple tattoos. Powter is author of several books, three of which became New York Times best-sellers in the 1990s. In 1994, Powter also starred in her own talk-show style television program called The Susan Powter Show, which ran for one season.