Marc Siegel M DMarc Siegel, M.D., is a practicing internist and associate professor at the New York University School of Medicine. He is a columnist for the Los Angeles Times, a member of USA Today's board of contributors, and a frequent contributor to The Washingtn Post, Slate, and the New York Post. He has appeared regularly on NBC's Today show, FOX News Channel, CNN, and NPR. Read More Read Less