The world is getting much, much heavier. And we can expect a massive increase in obesity-related medical costs as a result. Obesity rates are at new highs in the U.S., according to the most recent data from the CDC, with 40% of adults qualifying as obese. But as the graphic shows, obesity is increasingly a global problem—and one that affects a growing number of children. A new study by Imperial College London and the World Health Organization found that child and teen obesity has increased 10-fold worldwide over the past 40 years. The World Obesity Federation estimates that the global cost of treating obesity-related health problems will reach $1.2 trillion annually by 2025.