By Stephanie Nebehay GENEVA (Reuters) – The World Health Organization said on Tuesday governments should raise taxes on sugary drinks to fight what it says are global obesity and diabetes epidemics. If retail prices of sugar-sweetened drinks are increased by 20 percent through taxation, there is a proportional drop in consumption, it said in a report titled “Fiscal Policies for Diet and Prevention of Noncommunicable Diseases”. Obesity more than doubled worldwide between 1980 and 2014, with 11 percent of men and 15 percent of women classified as obese – more than 500 million people, the WHO said.