In Guatemala – the country with the highest rates of malnutrition in the Americas – roughly half of the nation's children are "stunted" and experience slow growth, poor school performance and, later in life, lower economic productivity. In the heavily Mayan western highlands of Guatemala, where poverty rates top 80 percent, the ratio of stunted children is closer to 7 in 10. Roger Thurow and Hari Sreenivasan report for the PBS NewsHour.