Obesity has long been a chief health concern in the United States.
And a new study led by the Harvard T.H. Chan School of Public Health says it may only get worse in the decade to come.
The report, published Wednesday in the New England Journal of Medicine, predicts that roughly 48.9 percent of American adults will be obese by 2030, with approximately 24.2 percent of adults projected to have severe obesity.
At least 35 percent of each state’s population will be obese, the study predicts.
“What’s even more concerning is the rise in severe obesity,” lead author Zachary Ward, a programmer/analyst at Harvard T.H. Chan School’s Center for Health Decision Science, said in a video discussing the study. “We find that nationally about 1 in 4 adults are projected to have severe obesity — this is usually over 100 pounds of excess weight.
“This was surprising from the study because severe obesity has typically been a rare condition. But we find that it’s growing pretty rapidly in a lot of states.”
Researchers estimate that currently 40 percent of adults are obese and 18 percent are severely obese, according to the Chan School of Public Health. Obesity is considered a body mass index of 30 or higher, with severe obesity considered a BMI of 35 and up.
The study, which placed an emphasis on trying to determine trends and predictions for each state rather than just at the national level, took a look at 20-plus years of self-reported BMI data from over 6.2 million adults.
For Massachusetts, the report predicts that by 2030, 42.3 percent of adults will be obese, while 20 percent of adults with have severe obesity, according to the numbers.
Slightly more men will be obese than women — or 43.1 percent compared to 41.7 percent — but more women will be severely obese than men, 21.5 to 18.7 percent, respectively.
Elsewhere in New England, the study predicts 48.8 percent of adults will be obese and 24.1 will be severely obese in New Hampshire by the end of the next decade.
Other predictions put adults in Vermont at 43.6 percent obese and 20.7 percent severely obese; Maine at 50.3 percent and 24.2 percent, respectively; Rhode Island at 47.3 percent and 22.9 percent; and Connecticut at 46.6 percent and 22.5 percent.
“Although previous criticisms of obesity projections — often based on small samples over short periods — argue that changes in obesity prevalence have not followed a predictable pattern, we observed remarkably stable and predictable trends across a wide range of states and demographic subgroups,” the authors wrote.
They predict that severe obesity will be “the most common BMI category” nationally among black non-Hispanic adults, women, and low-income adults, or those making an annual household income of less than $50,000.
Some states, meanwhile, will reach obesity rates near 60 percent among adults, especially in parts of the South, the report shows.
“The high projected prevalence of severe obesity among low-income adults has substantial implications for future Medicaid costs,” Ward said in a statement. “In addition, the effect of weight stigma could have far-reaching implications for socioeconomic disparities as severe obesity becomes the most common BMI category among low-income adults in nearly every state.”
Ward said researchers hope the study gives state lawmakers a better sense of where the issues are heading so they can intervene. Policies to help cut down on sugar intake, such as taxing sugary drinks, could be relatively inexpensive and effective, he said in the video.
“In much of our work, we find that prevention is going to be the key to managing, to better managing this epidemic,” he said.