The 4-Hour Body: An Uncommon Guide to Rapid Fat-Loss, Incredible Sex, and Becoming Superhuman is a nonfiction book by American writer Tim Ferriss. It was published by Crown Publishing Group in 2010. It focuses on diet, with chapters on exercise, sleep, and sexual performance. It debuted at number one on the New York Times Bestseller List and spent three weeks in the top three. The book elicited some controversy for its claims.