U.S. adults continue to put on the pounds. New data show that nearly 40 percent of them were obese in 2015 and 2016, a sharp increase from a decade earlier, federal health officials reported Friday.
The prevalence of severe obesity in U.S. adults is also rising, heightening their risks of developing heart disease, diabetes and various cancers. According to the latest data, published Friday in JAMA, 7.7 percent of U.S. adults were severely obese in the same period.
The data – gathered in a large-scale federal survey that is considered the gold standard for health data – measured trends in obesity from 2015 and 2016 back to 2007 and 2008, when 5.7 percent of U.S. adults were severely obese and 33.7 percent were obese. The survey counted people with a body mass index of 30 or more as obese, and those with a BMI of 40 or more as severely obese.
Public health experts said that they were alarmed by the continuing rise in obesity among adults and by the fact that efforts to educate people about the health risks of a poor diet do not seem to be working.
“Most people know that being overweight or obese is unhealthy, and if you eat too much that contributes to being overweight,” said Dr. James Krieger, clinical professor of medicine at the University of Washington and executive director of Healthy Food America, an advocacy group. “But just telling people there’s a problem doesn’t solve it.”
The latest data from the National Health and Nutrition Examination Survey come at a time when the food industry is pushing back against stronger public health measures aimed at combating obesity.
In recent NAFTA negotiations, the Trump administration has proposed rules favored by major food companies that would limit the ability of the United States, Mexico and Canada to require prominent labels on packaged foods warning about the health risks of foods high in sugar and fat.
While the latest survey data do not explain why Americans continue to get heavier, nutritionists and other experts cite lifestyle, genetics and, most importantly, a poor diet as factors. U.S. fast-food sales rose 22.7 percent from 2012-2017, according to Euromonitor, while packaged-food sales rose 8.8 percent.
The latest survey data found that U.S. youth are faring somewhat better than adults. Among Americans ages 2 to 19, 18.5 percent were obese in the 2015 and 2016, while 5.6 percent were severely obese. (A severely obese youth is defined as being 120 percent above the 95th percentile of body mass index for age and gender.)
The study found the percentage of youths who are obese and severely obese rose slightly from the 2007-2008 time frame, but not enough to be statistically significant.
Dr. Craig Hales, co-author of the survey research, said that the small increase in childhood obesity “could be due to sampling error,” and that the upshot was “no increasing or decreasing trends over the last 10 years.”
“Something different is happening with adults and youth,” he said, adding that he wasn’t able to explain the reasons.
One group of youths that has seen statistically significant weight gain are the youngest children, ages 2 to 5. Obesity rates in this group rose to 13.9 percent in 2015 and 2016 from 10.1 percent in 2007 and 2008.
Scholars who study childhood obesity disagree about whether childhood obesity has plateaued or is increasing.
“We haven’t turned the tide. If anything, rates are continuing to climb upwards,” said Dr. David Ludwig, a nutrition professor at the Harvard T.H. Chan School of Public Health.
The 18.5 percent youth obesity rate in 2015-2016 marked an uptick following earlier years dating to 2007 and 2008 when it had held steady at about 17 percent.
Dr. William Dietz, director of the Stop Obesity Alliance at George Washington University, said that it is premature to reach any conclusions about the trend in childhood obesity.
“I’m worried about it for sure, but we need two more years of data,” he said. Still, he called the overall report “dismal,” given that the high rates of obesity mean high rates of disease and premature death.