One in five people worldwide will be obese by 2025, experts warn

If current trends continue, a fifth of the world's population will be obese by 2025.

That's according to experts who predict by 2025 18% of men and 21% of women will be obese.

Research shows that over a period of 40 years from 1975 to 2014 the number of men and women in the world classified as obese soared from 105 million to 641 million.

With each passing decade, the average person had become 1.5kg (3.3 pounds) heavier.

How is obesity measured?

  • The clinical definition of obese is a Body Mass Index (BMI) measurement of 30 or above

  • A BMI of 25 or above is considered overweight

  • BMI is measured by a person's weight in kilograms divided by the square of height in meters.

The new analysis of BMI trends, published in The Lancet medical journal, shows that since the 1970s average BMI around the world increased from 21.7 to 24.2 - just under the threshold for overweight.

Obesity by country

In 2014 China had the largest number of obese people in the world - 43.2 million men and 46.4 million women. Chinese men accounted for 16.3% of global obesity and women 12.4%.

Next in the obesity league table was the US, with 41.7 million men and 46.1 million women. They accounted for 15.7% and 12.3% of the world's obese individuals respectively.

UK men, 6.8 million of whom were obese in 2014, took eighth place in the table while British obese women who numbered 7.7 million ranked 11th.

If present trends continue, not only will the world not meet the obesity target of halting the rise in the prevalence of obesity at its 2010 level by 2025, but more women will be severely obese than underweight by 2025.

Professor Majid Ezzati, lead researcher

Despite the trend, excessively low body weight remained a serious public health issue in the world's poorest regions, the study authors pointed out.

In southern Asia, almost a quarter of the population were still underweight, and in central and east Africa more than 15% of men and 12% of women weighed too little.