05/15/2010 05:12 am ET Updated May 25, 2011

New U.S.D.A. Effort Targets Link between Obesity and Food Stamps

With a swipe of a food stamp debit card on a handheld credit machine, shoppers at the Harvest Home Farmers Market receive a stack of wooden tokens worth a dollar apiece. And for every five they cash in for bananas, lettuce and the like, they win a two-dollar "Health Bucks" coupon to buy more.

Read more on scientificamerican.com