More than half of the world's population will be overweight or obese by 2035 unless governments take decisive action to curb the growing epidemic of excess weight, a report has warned. About 2.6 billion people globally 38% of the world population " are already overweight or obese. But on current trends that is expected to rise to more than 4 billion people (51%) in 12 years' time, according to research by the World Obesity Federation. Obesity among children and young people is on course to increase faster than among adults. By 2035 it is expected to be at least double the rate seen in 2020, according to the federation's latest annual World Obesity Atlas report. It is expected to rise by 100% among boys under 18, leaving 208 million affected, but go up even more sharply " by 125% " among girls the same age, which would see 175 million of them affected. The federation is an alliance of health, scientific, research and campaign groups, and works closely on obesity with various global agencies. It wants governments to use tax systems; restrictions on the marketing of foods that are high in fat, salt or sugar; front-of-pack labels; and provision of healthy food in schools to address rising obesity. The federation's report also highlights that many of the world's poorest countries are facing the sharpest increases in obesity yet are the least well prepared to confront the disease. Nine of the 10 countries set to experience the biggest rises in coming years are low- or middle-income nations in Africa and Asia.