Grocery stores may not realize it, but they wield unparalleled insight into their customers’ eating habits. Each swipe of the loyalty card records food brought into the household, which makes up 60 to 70 percent of a person’s calories. John Hurdle, M.D., Ph.D., professor of Biomedical Informatics at the University of Utah, has developed QualMART, a tool that translates bar codes into USDA-based dietary data that gauges the healthfulness of what’s in a shopping cart, and how diets change over time. He is developing an opt-in program where customers with an eye toward improving their health can evaluate their choices and monitor their progress. Hurdle explains how such programs can be a smart way for health care providers, wellness programs, health insurance companies, and grocery store chains to provide incentives to encourage healthy living.