Almost a quarter of men and 27% of women are fat enough to be considered obese, the study found.
Doctors assessed 168,159 people aged 18 to 80 in 63 countries across five continents. Participants’ waist circumference was measured along with their weight and height to provide Body Mass Index (BMI) figures.
Lead author Dr Beverly Balkau, from the French state-run medical research institute Inserm, in Villejuif, said: “This is the largest study to assess the frequency of adiposity (body fat) in the clinic, providing a snapshot of patients worldwide.
“The study results show that excess body weight is pandemic, with one half to two-thirds of the overall study population being overweight or obese.
“Central adiposity adds significantly to the risk of developing heart disease and particularly of developing diabetes.”
She said waist circumference was a more accurate marker of heart disease and diabetes risk than BMI.
The findings were published by the American Heart Association journal Circulation.
More than half the study population — 56% of men and 71% of women — had over-wide waistlines measuring 37 inches and 31.5 inches respectively.
For men, every extra 5.5 inches around the waist corresponded to a 35% higher frequency of heart disease, Dr Balkau said. For women, an increase of about six inches equated to a 40% greater rate of heart disease.
As measured by BMI, more than 60% of men and 50% of women were either overweight or obese. People with a BMI of 25 or more are considered overweight and 30 or more obese.