Obesity is a greater burden on the UK's economy than armed violence, war and terrorism, costing nearly £47bn a year, a report has found.
The study, commissioned by consultancy firm McKinsey and Company, revealed obesity has the second-largest economic impact on the UK behind smoking, generating an annual loss equivalent to 3% of GDP.
More than 2.1 billion people around the world - or nearly 30% of the global population - are now overweight or obese, with the figure set to rise to almost half of the world's adult population by 2030, according to the McKinsey Global Institute.
It has now called for a "co-ordinated response" from governments, retailers, restaurants, and food and drink manufacturers to address the "global obesity crisis".
A series of 44 interventions could bring 20% of overweight or obese people in UK back to normal weight within five to 10 years, the report said.
This would save around £16bn a year in UK, including an annual saving of about £766m in the NHS, according to the study.
The report found the economic impact from smoking in the UK was £57bn in 2012, or 3.6% of GDP, while the country suffered a £43bn annual loss from armed violence, war and terrorism or 2.5% of GDP.
In the UK, Government efforts to tackle obesity were "too fragmented to be effective", while investment in obesity prevention was "relatively low given the scale of the problem", the report said.
The UK spends less than £638m a year on obesity prevention programmes - about 1% of the country's social cost of obesity, the study found.
But the country spends about £6bn a year on the medical costs of conditions related to being overweight or obese and a further £10bn on diabetes, it claimed.