The old Food Guide Pyramid from the USDA was misleading, perhaps because the Department of Agriculture was looking out for the interests of agricultural businesses as well as the health of consumers. Have the multiple new Food Pyramids that have replaced it corrected its shortcomings? We’ll find out what to believe–and what to eat–from one of the country’s foremost nutrition researchers. Guests: Walter Willett, MD, DSc, Chairman of the Department of Nutrition, Harvard School of Public Health; Professor of Medicine at the Harvard Medical School. Author: Eat, Drink & Be Healthy: The Harvard Medical School Guide to Healthy Eating. Rebecca Wood, cookbook writer and winner of the James Beard and IACP/ Julia Child Cookbook Awards. Author: The Splendid Grain and The New Whole Foods Encyclopedia.