According to The Global Burden of Disease report, a large study published in The Lancet in December 2012, for the first time in human history, overeating is causing more health problems globally than is malnutrition. In 1990, the leading global health problem, as estimated by shortened life span, was under-nutrition. When the study was repeated with data from 2010, under-nutrition had fallen to the 8th leading factor in life span reduction while a high body mass index (being overweight) was the 6th leading cause of “disease burden.”
For the full report, see http://www.thelancet.com/themed/global-burden-of-disease. For a summary of the report, see http://www.newscientist.com/article/mg21628963.600-overeating-now-bigger-global-problem-than-lack-of-food.html.