At least once a week during dinner, Cathy Smith and her husband, Robert, are confronted with the same choice: Don't let the kids have seconds or forgo a meal themselves.

“I have growing children, and I want to make sure they have enough portions to nourish themselves,” says Smith, 40, a mother of five who works at an Atlanta-area school district as a recruiter. “It’s to the point that we have stopped buying cereal because milk is so expensive.”