The peer-reviewed paper, published in BMJ Global Health, provides the first country-by-country estimate of the economic impacts of obesity, a major driver of other non-communicable diseases such as cancer, diabetes and heart conditions.

It also included projections for the numbers of people in each country who are overweight or obese—defined as a body mass index in adults greater or equal to 25 and 30.

"Globally, nearly two in three adults are now living with overweight and obesity. And we project that will be three in four adults by 2060," lead author Rachel Nugent told reporters at a briefing on the margins of the United Nations General Assembly.

The conditions currently cost 2.2 percent of global GDP, and the biggest increases are expected to be seen in lower-resourced countries.

China, the United States and India are projected to experience the highest impact in absolute terms -- costing the countries US$10 trillion, $2.5 trillion and $850 billion, respectively.

As a proportion of the economy, the worst impacted countries are set to include the United Arab Emirates, where obesity would account for 11 percent of GDP, and Trinidad and Tobago at 10.2 percent.

The report analyzed both direct costs, made up primarily of medical fees, and indirect costs from premature mortality and lost productivity. Previous papers had only focused on the former.

"Less visible costs constitute a drag on development," said Nugent, vice president of non-communicable diseases at non-profit research firm RTI International.

"We could be developing and growing faster, and improving people's livelihoods faster, if we were not sort of experiencing this lower productivity, early mortality."

No to stigma

Population and economic growth are the primary drivers of obesity prevalence -- as countries increase their incomes, they experience changes in diet to highly processed foods, she explained.

In rich nations, aging populations are also a major factor as older people find it harder to lose weight.

Francesco Branca of the World Health Organization said there were a number of ways to respond to the obesity epidemic and avoid the worst outcomes.

"Having policies that, for example, shape the pricing of food -- so the foods which are contributing most to obesity, such as drinks or foods high in fat and sugars need to be priced higher," he said.

Other steps include better labeling—and in addition to prevention measures, better access to counseling and drug therapies as treatments.

The report stressed the economic costs of high weight and obesity "are not attributable to individual behavior" but rather a consequence of social and commercial priorities shaping environments.

As such, responsibility for tackling the issues lies with those in power. 

"We need to recognize that obesity is a complex disease with complex interactions and solutions and stop blaming these conditions on individuals, stop the stigma," said Simon Barquera, director of Mexico's Nutrition and Health Research Center.