Back in 1961, residents of far-flung countries ate very different mixes of crops (blue, below). By 1985 the disparities worldwide had shrunk (orange), and daily fare became even more homogeneous by 2009 (magenta). In nearly 50 years the differences in foods eaten narrowed by 68 percent. Prevalent staples such as wheat have become even more dominant, and oil crops such as soybean, palm and sunflower have risen sharply (bottom right). The convergence comes at the expense of many minor crops, says Colin Khoury of the International Center for Tropical Agriculture. People are consuming more processed foods made from a small number of ingredients and are frying with oils instead of steaming. Although the resultant increase in calories has been needed in certain regions, scientists say obesity, diabetes and heart disease are rising globally. They are also concerned that if one crop falters because of disease or drought, food prices could soar and supplies across continents could crumble.

SOURCE: “INCREASING HOMOGENEITY IN GLOBAL FOOD SUPPLIES AND THE IMPLICATIONS FOR FOOD SECURITY,” BY COLIN K. KHOURY ET AL., IN PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES USA, VOL. 111, NO. 11; MARCH 18, 2014. Graphic by Jen Christiansen