The world’s obesity epidemic now has 2.1 billion people in its grasp.
The number in 1980 stood at 875 million.
No one country has succeeded yet in treating the epidemic, according to the Lancet which published a new study.
The rate of increase of overweight and obesity was greatest between 1992 and 2002, but has slowed down in the past decade, especially in developed countries.
The highest rates in the world are found in the US, China and Russia.
The UK had the third highest rate in Europe, but was not in the global top ten. Nevertheless, 67% of British men and 57% of British women are overweight or obese.
Overall, more men in developed countries are obese, while in lesser developed nations more women are.
Increasing inactivity was given the primary blame for the rise in obesity, and that was put down to greater reliance on transport and desk-bound and computer-lead jobs and entertainment.
Children and adults were not building up enough functioning muscle mass, and "classical eating" had been replaced by "uncontrolled food intake" spread over the day, said one of the report’s authors.
Prof John Newton at Public Health England said poor nutrition and lack of exercise were a big risk factor in Britain's most deprived areas.
He added: "Obesity is a complex issue that requires action at national, local, family and individual level; everyone has a role to play in improving the health and well-being of the public, and children in particular."
More than half of the world's 671 million obese people live in 10 countries, ranked in order:
US
China
India
Russia
Brazil
Mexico
Egypt
Germany
Pakistan
Indonesia
Source: The Lancet
