Researchers found that moms were more likely to stop buying junk food when it cost more. Paul Vernon/AP hide caption

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Not only are kids snacking more frequently, but they're eating more unhealthful foods, too. iStockphoto.com hide caption

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Scientists are working to understand what hormonal and physiological cues in the body lead the brain to respond to food emotionally. iStockphoto.com hide caption

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Bob Karch is the chairman and a professor in the Department of Health and Fitness at American University. Here, he helps cross-country champion Steve Hallinan check his heart rate while cross-training on the bike. Allison Aubrey/NPR hide caption

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Bryce Marcus is a fifth-grader at the KIPP Infinity School in the West Harlem neighborhood of New York City. His curriculum includes emotional development training that teaches him to replace negative thinking with more realistic and flexible thinking. Allison Aubrey/NPR hide caption

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Sam Kass, the assistant White House chef, picks spinach from the garden. Maggie Starbard/NPR hide caption

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