05/21/13- Tuesday's Topical Currents is with nutritionists Jayson and Mira Calton. They’ve developed a system to determine the healthiest options among the some 40,000 food offerings in the mega-mart. With a bit of effort, shoppers can avoid processed sugars, high fructose corn syrup, refined flour, artificial colors, and nitrites. They’ve written, RICH FOOD/POOR FOOD: THE ULTIMATE GROCERY PURCHASING SYSTEM. That’s Topical Currents at 1pm on WLRN-HD1 rebroadcast at 7pm on WLRN-HD2 and audio on-demand after the live program.