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A new report looks at obesity levels worldwide.Getty Images
  • A new report has found that obesity trends have shifted significantly in the last 30 years.
  • Researchers find rates of obesity have risen drastically.
  • Experts say that the study further cements what those in the field have known for a long time.

A new analysis, recently published in the Lancet, has found that the worldwide trends among people who are either obese or underweight have shifted over the last 30 years.

Now over 1 billion people are estimated to have obesity and the number of people who are underweight has decreased.

The report looks at 3,663 studies, spanning from 1990 to 2022, and involves 222 million people overall. The indicator used was body mass index, which the authors acknowledged is an imperfect, though widely available, measure.

The researchers, who were part of the NCD Risk Factor Collaboration in conjunction with the World Health Organization, found that, in the vast majority of the world, the combined issues of being underweight/thin or obese have increased.

The number of people who are obese has increased significantly since 1990.

For women, 2003 was the last year that the average person was more likely to be underweight than obese. For men, that year was 2009.

Today, more than a billion people in the world today can be characterized as having obesity.

Dr. Chris Damman, a clinical associate professor at the University of Washington who specializes in internal medicine and gastroenterology, says that this research confirms what those in the field have known for decades and highlights serious concerns about the trajectory of these trends.

“As we transition from countries which have had [a] higher prevalence of underweight we’re moving directly into overweight, obesity, and metabolic disease,” Damman said. “We’re really trading one problem for another. And the study confirms that understanding of what’s happening with nutrition in the world.”

The report also found that not only are more adults trending towards having obesity, so are children and adolescents.

The increasing number of obese adults worldwide was evident as early as the 1970’s and 1980’s, according to Dr. Eric Sternlicht, PhD, an associate professor at Chapman University who teaches a range of courses in their health sciences faculty. However, he says that this trend translating to younger populations is a growing problem.

For context, over the timespan studied, 1990 to 2022, the number of children with obesity rose drastically, Sternlicht said. The number of girls with obesity rose from 1.7% in 1990 to 6.9% in 2022. For boys with obesity, the number rose from 2.1% in 1990 to 9.3% in 2022, according to the report.

“Our kids are no longer eating the traditional diets,” Sternlicht said. “So, it’s not surprising to me, as we become more mechanized, and especially with the advent of smartphones and computers, the amount of activity that individuals are doing is reduced.”

While there are still significant parts of the world where people are underweight, the steady rise of people with obesity has made headlines.

The researchers link these trends to an increase in sedentary lifestyles and an increase in people being able to eat calorie-dense foods at restaurants or other places outside of their homes.

Damman points to a host of societal issues that have become key culprits in the sharp rise of obesity that is identified by the study, particularly in countries with a comparatively high level of household income.

“How do you prevent this is the million-dollar question. And, for the longest time we’ve known the solution is simple. It’s to eat a largely plant-based whole food diet, tons of epidemiological and interventional data support that,” Damman said. “Why isn’t that happening? Well, there are questions of convenience, of marketing on the part of big food and busy lifestyles that have largely precluded a return to that healthy diet, which we had historically before the advent of ultra processed foods.”

Sterlich points out that another concern is the socio-economic realities at play here, particularly when it comes to issues like food deserts and government programs that have pushed people towards highly processed yet convenient foods.

Sterlich points out it can cost much more to get healthy fresh vegetables than processed foods.

“A parent will pay three and a half dollars to get four meals for her family or his family,” Sterlich said. “Whereas. if there was a salad at that same restaurant, which there no longer is at fast food restaurants, that would be seven to nine dollars.”