JuJu Harris is the author of The Arcadia Mobile Market Seasonal Cookbook. A former recipient of government food assistance, she now teaches healthy eating skills to low-income families in Washington, D.C. Courtesy of Molly M. Peterson hide caption

itoggle caption Courtesy of Molly M. Peterson

At NPR's Sound Bites Cafe, all food gets coded with one of three circles: Green is reserved for the most healthful dishes; yellow flags the "good choices;" and red signals the high-calorie foods to grab "on occasion." NPR hide caption

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A Safeway customer browses in the fruit and vegetable section at Safeway in Livermore, Calif. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

How a wealthy table set with a second course in the month of January would look, according to Mary Smith of Newcastle, in her 1772 book, The complete house-keeper and professed cook. British Library hide caption

itoggle caption British Library

Dried beans and legumes are healthy and cheap. iStockphoto.com hide caption

itoggle caption iStockphoto.com