Obese Australian Man
A man crosses a main road as pedestrians carrying food walk along the footpath in central Sydney, Australia, August 12, 2015. Reuters/David Gray

There are now more obese people in the world compared to underweight ones. An analysis of global trends in body mass index (BMI) estimate there are 641 million obese people in the world, comprising 13 percent of the global population, while the underweight are only nine percent.

The 641 million in 2014 is a big jump from 105 million in 1975, says a new study published on The Lancet on Friday. Majid Ezzati, professor at Imperial College London’s School of Public Health, warns that the epidemic of severe obesity gas become too extensive it could not be addressed by medications, such as drugs that lower blood pressure or treat diabetes, or physical exercise alone.

Australia is a major contributor to the obesity problem with Aussie men placing 6th and women 9th in global obesity rankings, reports The Sydney Morning Herald. The problem has worsened for Australian males whose average BMI is 27.5 and women (26.8), which are in the overweight range of 25 to 29.9. The healthy BMI is from 18.5 to 24.9.

The BMI is derived by dividing weight in kilogrammmes by height in metres squared. A BMI over 25 in overweight, over 30 is obese and more than 40 morbidly obese.

Given the current trends, 37.8 percent of Australian men and 37 percent of women would be obese by 2025, the study forecasts. Globally, it would be 21 percent for females and 18 percent for males within the next decade.

Women sit on a bench in New York's Times Square May 31, 2012. Reuters/Brendan McDermid

The most obese are from American Samoa, French Polynesia and Qatar which dominated the top three nations for both gender. On the opposite end are residents of East Timor, Ethiopia and Eritrea.

Ezzati says, “The number of people across the globe whose weight poses a serious threat to their health is greater than ever before,” quotes Reuters. The professor urges for coordinated global steps to be taken such as pricing of healthy food versus unhealthy food or taxing highly processed food and those with high sugar content.

If the problem with obesity would remain unchecked, it would “bankrupt our already overwhelmed healthcare systems,” warns David Crawford, professor and co-director of the Institute for Physical Activity and Nutrition at Deakin University.

But the study, which involved the World Health Organisation and more than 700 researchers worldwide who analysed weight and height data of almost 200 million adults from 186 nations, notes that low body weight is also a major public health problem. Almost one-fourth of the population in South Asia is underweight, while in Central and East Africa, it is the problem of 12 percent of women and 15 percent of men.