A ‘growing epidemic’: About half of U.S. adults will be obese by 2030, researchers predict

Boston — Nearly half of U.S. adults will qualify as obese by 2030, while one-quarter will contend with severe obesity, researchers at the Harvard T.H. Chan School of Public Health project.

The researchers analyzed self-reported body mass index data from nearly 6.3 million adults who participated in the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System Survey from 1993 to 2016. BMI is calculated by dividing a person’s weight in kilograms by the square of his or her height in meters. A BMI of 30 or higher is considered obese, while a BMI of 35 or greater is classified as severely obese.

Using their findings, the researchers predict that by 2030, 48.9% of adults will be obese and 24.2% will be severely obese. Additionally, the prevalence of obesity will be greater than 50% in 29 states and no less than 35% in any state.

“Thirty-five percent (prevalence) is sort of considered a high level for the past few years,” Zachary Ward, lead study author and programmer/analyst at the Chan School’s Center for Health Decision Science, says in a video posted in conjunction with the findings. “So, this means that we project that what will be the best states with the lowest obesity prevalence are going to be the same level as some of the worst states now. So, obesity is rising in every state in the U.S., and some states are going to be at a very high level.”

The researchers estimate that 40% of adults today are obese, while 18% are severely obese. In the video, Ward says the estimated growth in the latter category is “even more concerning” because severe obesity “has typically been a rare condition.”

Ward adds in the video that one of the most effective interventions researchers found was limiting intake of sugary beverages.

“In much of our work, we find that prevention really is going to be the key to better managing this epidemic,” Ward says. “It’s really hard to lose weight. It’s really hard to treat obesity, and so prevention really has to be at the forefront of efforts to combat this growing epidemic.”

The study was published online Dec. 19 in the New England Journal of Medicine.