NEW YORK — The past 40 years have seen an unprecedented increase in the number of obese adults worldwide, climbing to about 640 million — more than six times the total of 105 million in 1975.
If the trend continues, about one-fifth of adults will be obese by 2025.
The rate has more than doubled for women and tripled for men, according to an analysis published in the Lancet. The chance of meeting a goal set by the World Health Organization to halt the increase over the next decade is, according to the study, “virtually zero.”
They should be as nervous as a cat on a hot tin roof about the tsunami of diabetes that’s coming their way.
Excess weight raises the risk of diabetes, heart disease and other chronic conditions, and governments need to prepare for skyrocketing health costs, Bill Dietz of George Washington University said.
“They should be as nervous as a cat on a hot tin roof about the tsunami of diabetes that’s coming their way,” Dietz said. “The cost of this rise in the prevalence of obesity is going to be staggering.”
Behind the global spike is greater access to cheap food.
“It has been very easy, as countries get out of poverty, to eat a lot, and to eat a lot of unhealthy calories,” said Majid Ezzati, the study’s senior author and chair of global environmental health at Imperial College London.
The price of fresh fruits, vegetables and whole grains are often “noticeably more than highly processed carbohydrates,” he said.
A person who has a body-mass index higher than 30, or weighs at least 203 pounds and is five-foot-nine, is considered obese. The world population’s average weight has increased by about 3.3 pounds per decade since 1975, the researchers estimate.
Ezzati and hundreds of colleagues from around the world gathered data from surveys that measured the height and weight of 19 million adults. They then used statistical methods to estimate trends in global and national weight patterns from 1975 to 2014.
The main takeaway? Excess weight has become a far bigger global health problem than weighing too little. While low body weight is still a health risk for parts of Africa and South Asia, being too heavy is a much more common hazard around the globe.
For women, this transformation took place many years ago. Obese women have outnumbered those who are underweight for more than a decade. For men, being underweight was a bigger problem until about 2011. Adults are considered underweight if their BMI is below 18.5, or weighing less than 125 pounds for someone who is five-foot-nine. In 1975, more than twice as many people were underweight than obese.
Ezzati said the trends are related. “The issue really comes down to people either not having enough to eat or not having enough healthy food to eat,” he said. “It becomes a manifestation of the same problem.”
No government has found a way to stop rising obesity, though some are trying. Mexico, with almost two-thirds of its population overweight or obese, enacted a national tax on sugary beverages in 2014.
Ezzati said the world needs to focus on making more healthy foods competitive with cheap, processed foods. “To me, how to change the price of good things is perhaps the bigger question going forward,” he said.
The analysis also estimates an alarming rise of extreme cases of obesity. The global rate of severe obesity, or BMI over 35, is on pace to surpass nine per cent in women and six per cent in men by 2025. That category now includes 39 million adults in the U.S. In 1975, it was four million.
Meeting the WHO target of halting the rise in obesity by 2025 “will require action of monumental proportions,” Boyd Swinburn, a professor of population nutrition and global health at the University of Auckland in New Zealand, said.