Schoolgirls eat a free midday meal in Hyderabad, India, last month. India has offered such meals since the 1960s to persuade impoverished parents to send their children to school. A U.N. report released Tuesday finds modest progress in the worldwide fight against chronic hunger. Mahesh Kumar A./AP hide caption

itoggle caption Mahesh Kumar A./AP

In an experiment, people who saw a picture of a big bowl of soup before eating lunch were less hungry a few hours later than those who saw a smaller bowl, regardless of how much they ate at the meal. stuart burford photography/iStockphoto.com hide caption

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Somali girls line up to receive a hot meal in Mogadishu last year after the worst drought in the Horn of Africa in decades, compounded by war, put millions in danger of starvation. Roberto Schmmidt/AFP/Getty Images hide caption

itoggle caption Roberto Schmmidt/AFP/Getty Images