If current trends continue, about one-fifth of adults around the world will be obese by 2025. That trajectory defies the World Health Organization's goal to halt the rise in obesity rates around the globe by the same year. And according to a new analysis of the largest global data set on obesity, the spread of obesity in poor countries could wreak havoc on their health systems in an unprecedented way.
"At least in the rich world, we have bought our way out of it to a large extent," said lead study author Majid Ezzati, a professor of global environmental health at Imperial College London. "But obesity in the middle- and low-income world is the wildcard of global health.”
In other words, high-income countries like the U.S. or the U.K., which Ezzati also projects will have increasing obesity rates, won’t be hit as hard by obesity-related diseases because they have more experience with the condition and more resources to treat people with related complications like Type 2 diabetes and high blood pressure.
While the march of obesity seems hopeless, experts say that countries can fight the trend by closely looking at nations where obesity and overweight isn't increasing at all. What are they doing right, and how can other countries re-create the same conditions that help people stay at normal weights?
The obese now outnumber underweight people
Forty years ago, the number of underweight people was more than double the number of obese, explained Ezzati. Only 105 million adults were obese in 1975, a number that has now ballooned to 641 million. Meanwhile, significant pockets of underweight have persisted for decades in South Asia and Africa.
While it may seem like increasing numbers of obese people is an arguable -- if perverse -- improvement on people who are starving, the increasing proportion of obese people in low- and middle-income nations could one day saddle these struggling countries with a devastating and costly healthcare burden because of diseases and syndromes linked to obesity.
Based on past trends, the regions at highest risk of obesity numbers that could overwhelm their health systems include Pacific Island nations, the Middle East, North Africa and some Caribbean islands. Conversely, because women in Singapore, Japan, France and Switzerland have had almost no increase in average BMI over the past four decades, Ezzati predicts that these populations will manage to avoid the future obesity crisis.
The largest global study on obesity to date
The new data, published Thursday in the British medical journal the Lancet, is the largest population-base dataset on obesity to date, according to the researchers. Ezzati compiled the data with the help of over 700 research collaborators from around the world. It encompasses weight measurement data from almost 20 million participants across 186 countries between the years 1975 and 2014. The analysis is unique because it includes categories for underweight (a body mass index of less than 18.5), severely obese (a BMI of 35 or more) and morbidly obese (a BMI of 40 or more).
To Ezzati, the two most important points of his study are that severe and morbid obesity is increasing and undernourishment continues to persist. More than a fifth of men in India, Bangladesh, Afghanistan and Ethiopia and a quarter of women in Bangladesh and India are underweight. Meanwhile, more than one in four severely obese men and one in five severely obese women live in the U.S.
“Extremes are becoming not uncommon,” he said. “That's the major news."
In the graphs below, you can toggle between "Men" and "Women." Press the play button to see the change in trends over four decades.
Global Underweight Trends
Global Overweight Trends
We need to borrow prevention methods from successful countries
Dr. James Levine, director of Obesity Solutions at the Mayo Clinic and Arizona State University, wasn’t involved in the publication of this study, but pointed out it isn’t the first time an analysis has predicted that obesity rates will continue to worsen. The world has been watching this slow-motion disaster for decades, he said, and it’s time to do something about it.
“We need to be looking at the models of success -- the countries that seem to be somehow winning their battle -- with greater intensity because the need is great and predicted to get even worse,” Levine told The Huffington Post. "The real question I think this paper poses is, are we standing on the shore watching the Titanic sink?”
He noted that Scandinavian countries are rich nations that don’t have the high numbers of obesity expected of a wealthy region. What are they doing right, he asked, and how can other companies replicate their results?
Ezzati agrees. While his paper doesn’t measure the effectiveness of food policy solutions that can help curb obesity or stamp out starvation, he hopes that the most high-risk countries heed the data’s warning and course-correct with strong laws to reverse the projected trends. Such laws could include regulating the way certain foods are marketed to children, taxing junk foods in a similar fashion to tobacco products and subsidizing foods like fresh vegetables and fruits, whole grains, legumes and healthy dairy products to make them more affordable for everyone.
“We have governments to make sure people eat enough, and not too much, and eat food that is healthy,” he said. “Make sure people, regardless of income, can have a minimum amount of healthy nutrition."