There are now 641 million obese people in the world today, up from 105 million in 1975.  A study published in The Lancet took data of body mass index (BMI) in 200 countries over the last 40 years.

For the first time, obese people outnumber underweight people.

The amount of obese men more than tripled, with 10.8 percent of men being obese up from 3.2 percent.  Women gained at a more moderate rate, but 14.9 of women are obese up from 6.4 percent since 1975.  

118 million of the 641 million obese adults live in just 6 english speaking countries:  Australia, Canada, Ireland, New Zealand, UK and the US.

In Australia about 27% of the adult population is obese.

Manny Noakes, the research director of the Health and Nutrition Program at CSIRO, says the numbers are alarming and impact not only on increasing chronic diseases but also on the environment.

“Heavier populations consume more fuels as well as food which is not sustainable,” Noakes says. “The low cost of junk foods and beverages is a contributor. Appropriate food policies and universal nutrition and healthy weight programs particularly targeting preconception are urgently needed.”

The amount of underweight people fell in both genders.  Men dropped to 8.8 percent from 13.8 percent and women to 9.7 percent from 14.6 percent.

“Over the past 40 years, we have changed from a world in which underweight prevalence was more than double that of obesity, to one in which more people are obese than underweight,” says senior author Majid Ezzati from the School of Public Health at Imperial College London.

“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.”

South Asia still has the highest percentage of people underweight with almost a fourth being classified as underweight.

In central and east Africa, levels of underweight men and women and still higher than average at 15 and 12% respectively.

While growing obesity rates are alarming, they should not overshadow the continuing underweight problem that is still occurring in the world’s poorer nations.

The authors warn that global trends in rising obesity should not overshadow the continuing underweight problem in poor countries.

Almost a fifth of the world’s obese adults, 118 million of them, live in six high-income English-speaking countries – Australia, Canada, Ireland, New Zealand, UK and the US. In Australia, about 27 percent of the population are obese.