Daniel S. Kirschenbaum, Ph.D., is the director of the Center for Behavioral Medicine & Sport Psychology in Chicago and a professor of psychiatry and behavioral sciences at Northwestern University Medical School. He has served as a consultant to dozens of professional journals, the U.S. Olympic Committee, the National Basketball Association, the Ladies Professional Golf Association, the World Scientific Congress on Golf and several major corporations. He is the author of The 9 Truths about Weight Loss. He lives in Chicago.