Last week, the FDA issued new rules regarding what it means to offer a food that’s “gluten free.” Their new ruling requires that these products contain fewer than 20 parts per million of gluten, a protein found in wheat, barley, rye and related grains. The FDA reports that this new definition is needed to help the growing number of Americans suffering from celiac disease — Estimates for people who suffer from this gluten allergy range from one and a half million to over 25 million. According to Dr. William Davis, author of the book Wheat Belly, the numbers of people with grain insensitivities may be even higher. Here’s a conversation with Dr. William Davis, which broadcast on KGNU Boulder/Denver earlier this month and includes a call-in segment. Monday, Dr. Davis launches his national tour of Wheat: The Unhealthy Whole Grain, and it’s starting in Denver.