The new study, led by scientists from Imperial College London and published in The Lancet, compared BMI among almost 20 million adult men and women from 1975 to 2014.
The researchers found obesity in men has tripled and more than doubled in women.
Lead author Prof. Majid Ezzat said it was an “epidemic of severe obesity” and urged governments to act.
The study, which pooled data from adults in 186 countries, found that the number of obese people worldwide had risen from 105 million in 1975 to 641 million in 2014.
Meanwhile, the number of underweight people had risen from 330 million to 462 million over the same period.
Global obesity rates among men went up from 3.2% in 1975 to 10.8%, while among women they rose from 6.4 % in 1975 to 14.9%.
This equates to 266 million obese men and 375 million obese women in the world in 2014, the study said.
The research also predicted that the probability of reaching the WHO’s global obesity target – which aims for no rise in obesity above 2010 levels by 2025 – would be “close to zero”.
The clinical definition of obese is a BMI – a measurement that relates weight and height – of 30kg/m2.
Prof. Majid Ezzati said: “Our research has shown that over 40 years we have transitioned from a world in which underweight prevalence was more than double that of obesity, to one in which more people are obese than underweight.
“Although it is reassuring that the number of underweight individuals has decreased over the last four decades, global obesity has reached crisis point.”
“We hope these findings create an imperative to shift responsibility from the individual to governments and to develop and implement policies to address obesity.
“For instance, unless we make healthy food options like fresh fruits and vegetables affordable for everyone and increase the price of unhealthy processed foods, the situation is unlikely to change.”
The team also examined the number of people who are underweight, and over the same time period the study suggested the rates had fallen from 14% to 9% in men, and 15% to 10% in women.
Other statistics from the study include:
The US House Ethics Committee has voted to release its report on former Republican Representative…
ABC News has agreed to pay $15 million to President-elect Donald Trump to settle a…
South Korea’s parliament has voted to impeach President Yoon Suk Yeol over his failed attempt…
Israeli war planes have carried out more than 100 air strikes in Syria on December…
President-elect Donald Trump has threatened to impose 100% tariffs on the BRICS countries if they…
Syrian troops have withdrawn from the city of Aleppo following an offensive by rebels opposed…