Across the globe, people have long been tipping the scales toward excessive increasing heaviness. Now, new research finds that more of the world's population is obese than underweight.
"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," Majid Ezzati, senior author of the paper and professor of public health at Imperial College London, said in a statement.
In the study, the researchers looked at data from 186 of the world's 200 countries, representing over 99 percent of the world's population. The data spanned from 1975 to 2014. The researchers looked at the percentage of adults who were underweight (which the researchers defined as having a body mass index, or BMI, below 18.5), obese (a BMI from 30.0 to 34.9), severely obese (a BMI from 35.0 to 39.9) or morbidly obese (a BMI greater than 40.0).
Results showed that in the last four decades, the percentage of men in the world who were underweight decreased from 13.8 percent to 8.8 percent, and the percentage of underweight women fell from 14.6 percent to 9.7 percent. [8 Reasons Our Waistlines Are Expanding]
Over the same time span, the prevalence of obesity increased from 3.2 percent to 10.8 percent in men and from 6.4 percent to 14.9 percent in women, according to the findings published today (March 31) in the journal The Lancet.
Some countries had no increase in their average BMI since 1975. These included Singapore, Japan, the Czech Republic, Belgium, France and Switzerland. The largest increases in BMI for men over the study period were seen in high-income English-speaking countries; for women, the largest increases were in central Latin America.
Out of all high-income, English-speaking countries, the United States had the highest average BMI (28). The researchers pointed out that more than one in four severely obese men in the world and nearly one in five severely obese women live in the United States. [The Best Way to Lose Weight Safely]
The researchers also noted that almost one-fifth of all obese adults (118 million people) and over a quarter of all severely obsess adults (50 million people) live in six high-income, English-speaking countries: Australia, Canada, Ireland, New Zealand, the United Kingdom and the United States. Polynesia and Micronesia tied for having the highest average BMI in the world, both with an average BMI of 32.2 for men and 34.8 for women.
While people are well-aware of the world's problems with ballooning weights, the researchers pointed out that many people in the world are still underweight. Although the percentage of the world's population that falls in this category has dropped, the authors stressed that the epidemic of obesity should not overshadow the needs of people who remain undernourished.
According to the findings, more than one-fifth of the men in India, Bangladesh, Timor-Leste, Afghanistan, Eritrea and Ethiopia are underweight. In Bangladesh and India, a quarter of the women are underweight. Timor-Leste has the lowest average BMI among women (20.8), and Ethiopia has the lowest for men (20.1).
In an editorial published alongside the study, Dr. George Davey Smith, a professor of epidemiology at the School of Social and Community Medicine in England, also emphasized the need to pay attention to underweight populations, even in light of the obesity epidemic. "A focus on obesity at the expense of recognition of the substantial remaining burden of undernutrition threatens to divert resources away from disorders that affect the poor to those that are more likely to affect the wealthier in these countries," Smith wrote in his editorial.
Although obesity is associated with potentially deadly health problems, many of those can be helped through medical intervention, which results in a world that is simultaneously fatter and healthier, Smith said. He noted that although obesity tends to be a disease of the poor in more affluent countries, being underweight is still a problem of the impoverished in many parts of the world.
Using post-2000 trends as a guide, the researchers estimated that global obesity will reach 18 percent in men and over 21 percent in women by 2025. The researchers also predicted that severe obesity will pass 6 percent in men and 9 percent in women by that same year.
At the same time, in the world's poorest regions, such as South Asia, the percentage of people who are underweight will remain a serious issue, the researchers said.