A woman walks by a sign advertising sugary drinks in a Brooklyn, USA, neighborhood
Credit: AFP/Spencer Platt

More than 640 million people globally now weigh in as obese and the world has more overweight than underweight people, according to an analysis of global trends in body mass index (BMI).

A startling increase in rates of obesity in the past 40 years means the number of people with a BMI of more than 30 has risen from 105 million in 1975 to 641 million in 2014, the study found. More than one in 10 men and one in seven women are obese.

BMI is calculated by dividing a person’s weight in kilograms by their height in metres squared, and is an indication of whether a person is a healthy weight. A BMI score over 25 is overweight, over 30 is obese and over 40 is morbidly obese.

“The number of people across the globe whose weight poses a serious threat to their health […]