Powter, Susan: - Susan Powter is an Australian born American motivational speaker, nutritionist, personal trainer, and author, three-time New York Times bestselling author, AOL's third largest seller in TV history, and the woman dubbed "the Lenny Bruce of Wellness" by Shape magazine, who rose to fame in the 1990s with her catchphrase "Stop the Insanity!", which was the centerpiece of her weight loss infomercial. She hosted her own talk show The Susan Powter Show in the 1990s.