The whole world is steadily becoming more obese, a new study shows, but not surprisingly, the U.S. is No. 1. The survey of 188 countries shows that nearly 30 percent of the global population, or 2.1 billion people, are either overweight or obese. Not a single country has lowered its obesity rate since 1980, the first of its kind study shows. And even though the United States accounts for just 5 percent of the world’s total population, Americans make up 13 percent of the global overweight and obese population.