There are now more obese adults in the world than underweight adults

LONDON -- The number of adults classified as obese now outweighs the number of underweight adults worldwide, according to the largest ever obesity study, published in the Lancet. 

The research -- led by scientists from Imperial College London, and involving the World Health Organization (WHO) and over 700 researchers across the globe ---- analysed body mass index (BMI) values among adults between 1975 and 2014. 

In total, the study used estimates from nearly 1,700 population-based studies for more than 19.2 million men and women in 186 countries.

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The NHS defines the BMI as "a measure that adults can use to see if they are a healthy weight for their height." According to NHS guidance, a healthy BMI is within the range of 18.5 and 24.9. A BMI under 18.5 is categorised as 'underweight', and BMIs in excess of 30 are considered 'obese'. 

The findings revealed that the world has moved from "an era when underweight prevalence was more than double that of obesity, to one in which more people are obese than underweight." 

Six nations -- Australia, Canada, Ireland, New Zealand, the UK and the U.S. -- recorded dramatic upticks in obesity levels during the past 40 years, with the number of obese people in the world increasing from 105 million in 1975 to 641 million in 2014. 

According to the study, this figure comprised 266 million obese men, and 375 million obese women in 2014.

"If present trends continue, [...] severe obesity will also surpass underweight in women by 2025."

The statistics presented in the new study do not mean that the problem of hunger and malnourishment has been solved, however. Though the gap between the number of obese adults worldwide and the number of underweight people has widened; the number of underweight people in the world has also risen. 

The study also found that the number of underweight people increased from 330 million to 462 million between 1975 and 2014. 

"Underweight remains a public health problem in the world’s poorest regions—namely south Asia and central and east Africa," the study says. 

Researchers predicted that the UK will have the highest levels of obese women in Europe by 2025 (38 percent), followed by Republic of Ireland (37 percent) and Malta (34 percent). 

"I am surprised by the suggestion that the UK will have the highest rates of obesity in Europe in a decade's time as the rate of increase for the past few years has been very small," Dr. Jennifer Mindell, a reader in Public Health at UCL, told Mashable. 

Jamie Blackshaw, national lead for obesity and healthy weight at Public Health England, said in a statement that the study "confirms what we already know". 

“Too many people are overweight and obese," says Blackshaw.  

"People who are overweight and obese suffer life-changing consequences and it costs the NHS more than £6 billion a year. The causes of obesity are complex and the environment we live in encourages poor diets and low levels of physical activity."

Original image has been replaced. Credit: Mashable

While the study's findings are based on estimates, Mindell believes the findings are "probably true". 

"This is a major study by a well-respected group. They have allowed for many of the factors that can distort comparisons between countries, such as differences in age distribution in the population or using self-reported rather than measured height and weight to calculate body mass index," she told Mashable. 

Mindell says that the size of the global obesity problem means that individual-based approaches will likely be ineffective.

"We need governments across the world to make healthier choices easier," she said.

“The number of people across the globe whose weight poses a serious threat to their health is greater than ever before," says professor Majid Ezzati, the senior author of the study from the School of Public Health at Imperial.

"And this epidemic of severe obesity is too extensive to be tackled with medications such as blood pressure lowering drugs or diabetes treatments alone, or with a few extra bike lanes," Ezzati said.

"We need coordinated global initiatives – such as looking at the price of healthy food compared to unhealthy food, or taxing high sugar and highly processed foods -- to tackle this crisis,” Ezzati continued.

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