Elson M. Haas, MD, has been in medical practice for more than 30 years and is the founder and director of the Preventive Medical Center of Marin in San Rafael, California. Dr. Haas is the author of seven books on health and nutrition including the new twenty-first-century edition of Staying Healthy with Nutrition: The Complete Guide to Diet and Nutritional Medicine ($39.95, Celestial Arts, 2006), as well as The New Detox Diet, The False Fat Diet, and the latest 2003 edition of Staying Healthy with the Seasons. Visit his Web site for more tips on healthy living.